ALSA sequencer code has an open race between the timer setup ioctl and
the close of the client. This was triggered by syzkaller fuzzer, and
a use-after-free was caught there as a result.
This patch papers over it by adding a proper queue->timer_mutex lock
around the timer-related calls in the relevant code path.
snd_seq_ioctl_remove_events() calls snd_seq_fifo_clear()
unconditionally even if there is no FIFO assigned, and this leads to
an Oops due to NULL dereference. The fix is just to add a proper NULL
check.
The 'umidi' object will be free'd on the error path by snd_usbmidi_free()
when tearing down the rawmidi interface. So we shouldn't try to free it
in snd_usbmidi_create() after having registered the rawmidi interface.
Found by KASAN.
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com> Acked-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[wt: file is sound/midi/usbmidi.c in 2.6.32] Signed-off-by: Willy Tarreau <w@1wt.eu>
snd_timer_user_read() has a potential race among parallel reads, as
qhead and qused are updated outside the critical section due to
copy_to_user() calls. Move them into the critical section, and also
sanitize the relevant code a bit.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.2: there's no check for tu->connected to fix up] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
In snd_timer_notify1(), the wrong timer instance was passed for slave
ccallback function. This leads to the access to the wrong data when
an incompatible master is handled (e.g. the master is the sequencer
timer and the slave is a user timer), as spotted by syzkaller fuzzer.
ALSA timer ioctls have an open race and this may lead to a
use-after-free of timer instance object. A simplistic fix is to make
each ioctl exclusive. We have already tread_sem for controlling the
tread, and extend this as a global mutex to be applied to each ioctl.
The downside is, of course, the worse concurrency. But these ioctls
aren't to be parallel accessible, in anyway, so it should be fine to
serialize there.
In ALSA timer core, the active timer instance is managed in
active_list linked list. Each element is added / removed dynamically
at timer start, stop and in timer interrupt. The problem is that
snd_timer_interrupt() has a thinko and leaves the element in
active_list when it's the last opened element. This eventually leads
to list corruption or use-after-free error.
This hasn't been revealed because we used to delete the list forcibly
in snd_timer_stop() in the past. However, the recent fix avoids the
double-stop behavior (in commit [f784beb75ce8: ALSA: timer: Fix link
corruption due to double start or stop]), and this leak hits reality.
This patch fixes the link management in snd_timer_interrupt(). Now it
simply unlinks no matter which stream is.
ALSA timer instance object has a couple of linked lists and they are
unlinked unconditionally at snd_timer_stop(). Meanwhile
snd_timer_interrupt() unlinks it, but it calls list_del() which leaves
the element list itself unchanged. This ends up with unlinking twice,
and it was caught by syzkaller fuzzer.
The fix is to use list_del_init() variant properly there, too.
The port subscription code uses double mutex locks for source and
destination ports, and this may become racy once when wrongly set up.
It leads to lockdep warning splat, typically triggered by fuzzer like
syzkaller, although the actual deadlock hasn't been seen, so far.
This patch simplifies the handling by reducing to two single locks, so
that no lockdep warning will be trigger any longer.
By splitting to two actions, a still-in-progress element shall be
added in one list while handling another. For ignoring this element,
a new check is added in deliver_to_subscribers().
Along with it, the code to add/remove the subscribers list element was
cleaned up and refactored.
The rawmidi read and write functions manage runtime stream status
such as runtime->appl_ptr and runtime->avail. These point where to
copy the new data and how many bytes have been copied (or to be
read). The problem is that rawmidi read/write call copy_from_user()
or copy_to_user(), and the runtime spinlock is temporarily unlocked
and relocked while copying user-space. Since the current code
advances and updates the runtime status after the spin unlock/relock,
the copy and the update may be asynchronous, and eventually
runtime->avail might go to a negative value when many concurrent
accesses are done. This may lead to memory corruption in the end.
For fixing this race, in this patch, the status update code is
performed in the same lock before the temporary unlock. Also, the
spinlock is now taken more widely in snd_rawmidi_kernel_read1() for
protecting more properly during the whole operation.
Also a similar warning is found but in another path:
Call Trace:
[< inline >] __dump_stack lib/dump_stack.c:15
[<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50
[<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482
[<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515
[<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133
[<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163
[<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185
[< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150
[<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252
[<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302
[<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528
[<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577
[< inline >] SYSC_write fs/read_write.c:624
[<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616
[<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185
In the former case, the reason is that virmidi has an open code
calling snd_rawmidi_transmit_ack() with the value calculated outside
the spinlock. We may use snd_rawmidi_transmit() in a loop just for
consuming the input data, but even there, there is a race between
snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack().
Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and
snd_rawmidi_tranmit_ack() separately without protection, so they are
racy as well.
The patch tries to address these issues by the following ways:
- Introduce the unlocked versions of snd_rawmidi_transmit_peek() and
snd_rawmidi_transmit_ack() to be called inside the explicit lock.
- Rewrite snd_rawmidi_transmit() to be race-free (the former case).
- Make the split calls (the latter case) protected in the rawmidi spin
lock.
Although ALSA timer code got hardening for races, it still causes
use-after-free error. This is however rather a corrupted linked list,
not actually the concurrent accesses. Namely, when timer start is
triggered twice, list_add_tail() is called twice, too. This ends
up with the link corruption and triggers KASAN error.
The simplest fix would be replacing list_add_tail() with
list_move_tail(), but fundamentally it's the problem that we don't
check the double start/stop correctly. So, the right fix here is to
add the proper checks to snd_timer_start() and snd_timer_stop() (and
their variants).
ALSA sequencer may open/close and control ALSA timer instance
dynamically either via sequencer events or direct ioctls. These are
done mostly asynchronously, and it may call still some timer action
like snd_timer_start() while another is calling snd_timer_close().
Since the instance gets removed by snd_timer_close(), it may lead to
a use-after-free.
This patch tries to address such a race by protecting each
snd_timer_*() call via the existing spinlock and also by avoiding the
access to timer during close call.
There are potential deadlocks in PCM OSS emulation code while
accessing read/write and mmap concurrently. This comes from the
infamous mmap_sem usage in copy_from/to_user(). Namely,
NULL user-space buffer can be passed even in a normal path, thus it's
not good to spew a kernel warning with stack trace at each time.
Just drop snd_BUG_ON() macro usage there.
ALSA OSS sequencer spews a kernel error message ("ALSA: seq_oss: too
many applications") when user-space tries to open more than the
limit. This means that it can easily fill the log buffer.
Since it's merely a normal error, it's safe to suppress it via
pr_debug() instead.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.2: this was still using snd_printk()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
ALSA sequencer OSS emulation code has a sanity check for currently
opened devices, but there is a thinko there, eventually it spews
warnings and skips the operation wrongly like:
WARNING: CPU: 1 PID: 7573 at sound/core/seq/oss/seq_oss_synth.c:311
When a TLV ioctl with numid zero is handled, the driver may spew a
kernel warning with a stack trace at each call. The check was
intended obviously only for a kernel driver, but not for a user
interaction. Let's fix it.
This reverts one hunk of
commit ef44a1ec6eee ("ALSA: sound/core: use memdup_user()"), which
replaced a number of kmalloc followed by memcpy with memdup calls.
In this case, we are copying from a struct snd_seq_port_info32 to a
struct snd_seq_port_info, but the latter is 4 bytes longer than the
32-bit version, so we need to separate kmalloc and copy calls.
Fixes: ef44a1ec6eee ('ALSA: sound/core: use memdup_user()') Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
This reverts one hunk of
commit ef44a1ec6eee ("ALSA: sound/core: use memdup_user()"), which
replaced a number of kmalloc followed by memcpy with memdup calls.
In this case, we are copying from a struct snd_pcm_hw_params32 to
a struct snd_pcm_hw_params, but the latter is 4 bytes longer than
the 32-bit version, so we need to separate kmalloc and copy calls.
This actually leads to an out-of-bounds memory access later on
in sound/soc/soc-pcm.c:soc_pcm_hw_params() (detected using KASan).
Fixes: ef44a1ec6eee ('ALSA: sound/core: use memdup_user()') Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
hrtimer_cancel() waits for the completion from the callback, thus it
must not be called inside the callback itself. This was already a
problem in the past with ALSA hrtimer driver, and the early commit
[fcfdebe70759: ALSA: hrtimer - Fix lock-up] tried to address it.
However, the previous fix is still insufficient: it may still cause a
lockup when the ALSA timer instance reprograms itself in its callback.
Then it invokes the start function even in snd_timer_interrupt() that
is called in hrtimer callback itself, results in a CPU stall. This is
no hypothetical problem but actually triggered by syzkaller fuzzer.
This patch tries to fix the issue again. Now we call
hrtimer_try_to_cancel() at both start and stop functions so that it
won't fall into a deadlock, yet giving some chance to cancel the queue
if the functions have been called outside the callback. The proper
hrtimer_cancel() is called in anyway at closing, so this should be
enough.
A slave timer instance might be still accessible in a racy way while
operating the master instance as it lacks of locking. Since the
master operation is mostly protected with timer->lock, we should cope
with it while changing the slave instance, too. Also, some linked
lists (active_list and ack_list) of slave instances aren't unlinked
immediately at stopping or closing, and this may lead to unexpected
accesses.
This patch tries to address these issues. It adds spin lock of
timer->lock (either from master or slave, which is equivalent) in a
few places. For avoiding a deadlock, we ensure that the global
slave_active_lock is always locked at first before each timer lock.
Also, ack and active_list of slave instances are properly unlinked at
snd_timer_stop() and snd_timer_close().
Last but not least, remove the superfluous call of _snd_timer_stop()
at removing slave links. This is a noop, and calling it may confuse
readers wrt locking. Further cleanup will follow in a later patch.
Actually we've got reports of use-after-free by syzkaller fuzzer, and
this hopefully fixes these issues.
ALSA dummy driver can switch the timer backend between system timer
and hrtimer via its hrtimer module option. This can be also switched
dynamically via sysfs, but it may lead to a memory corruption when
switching is done while a PCM stream is running; the stream instance
for the newly switched timer method tries to access the memory that
was allocated by another timer method although the sizes differ.
As the simplest fix, this patch just disables the switch via sysfs by
dropping the writable bit.
We have found that migration source will trigger a BUG that the refcount
of mle is already zero before put when the target is down during
migration. The situation is as follows:
dlm_migrate_lockres
dlm_add_migration_mle
dlm_mark_lockres_migrating
dlm_get_mle_inuse
<<<<<< Now the refcount of the mle is 2.
dlm_send_one_lockres and wait for the target to become the
new master.
<<<<<< o2hb detect the target down and clean the migration
mle. Now the refcount is 1.
dlm_migrate_lockres woken, and put the mle twice when found the target
goes down which trigger the BUG with the following message:
"ERROR: bad mle: ".
Signed-off-by: Jiufei Xue <xuejiufei@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
If a name contains at least some characters with Unicode values
exceeding single byte, the CS0 output should have 2 bytes per character.
And if other input characters have single byte Unicode values, then
the single input byte is converted to 2 output bytes, and the length
of output becomes larger than the length of input. And if the input
name is long enough, the output length may exceed the allocated buffer
length.
All this means that conversion from UTF8 or NLS to CS0 requires
checking of output length in order to stop when it exceeds the given
output buffer size.
[JK: Make code return -ENAMETOOLONG instead of silently truncating the
name]
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
udf_CS0toUTF8 function stops the conversion when the output buffer
length reaches UDF_NAME_LEN-2, which is correct maximum name length,
but, when checking, it leaves the space for a single byte only,
while multi-bytes output characters can take more space, causing
buffer overflow.
Similar error exists in udf_CS0toNLS function, that restricts
the output length to UDF_NAME_LEN, while actual maximum allowed
length is UDF_NAME_LEN-2.
In these cases the output can override not only the current buffer
length field, causing corruption of the name buffer itself, but also
following allocation structures, causing kernel crash.
Adjust the output length checks in both functions to prevent buffer
overruns in case of multi-bytes UTF8 or NLS characters.
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
udf_next_aext() just follows extent pointers while extents are marked as
indirect. This can loop forever for corrupted filesystem. Limit number
the of indirect extents we are willing to follow in a row.
[JK: Updated changelog, limit, style]
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Jan Kara <jack@suse.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[wt: udf_error() instead of udf_err() in 2.6.32] Signed-off-by: Willy Tarreau <w@1wt.eu>
If there is a problem with a scratched disc or loader, it's valuable to know
which error occurred.
Convert some debug messages to udf_error, neaten those messages too.
Add the calculated tag checksum and the read checksum to error message.
Make udf_error a public function and move the logging prototypes together.
Original-patch-by: NamJae Jeon <linkinjeon@gmail.com> Reviewed-by: NamJae Jeon <linkinjeon@gmail.com> Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Jan Kara <jack@suse.cz>
[wt: this one is only here to export udf_error() for next commit] Signed-off-by: Willy Tarreau <w@1wt.eu>
When recovery master down, dlm_do_local_recovery_cleanup() only remove
the $RECOVERY lock owned by dead node, but do not clear the refmap bit.
Which will make umount thread falling in dead loop migrating $RECOVERY
to the dead node.
Signed-off-by: xuejiufei <xuejiufei@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[wt: dlm_lockres_clear_refmap_bit() takes 2 args in 2.6.32] Signed-off-by: Willy Tarreau <w@1wt.eu>
If MODE SELECT returns with sense '05/91/36' (command lock violation)
it should always be retried without counting the number of retries.
During an HBA upgrade or similar circumstances one might see a flood
of MODE SELECT command from various HBAs, which will easily trigger
the sense code and exceed the retry count.
Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
The tda1004x was updating the properties cache before locking.
If the device is not locked, the data at the registers are just
random values with no real meaning.
This caused the driver to fail with libdvbv5, as such library
calls GET_PROPERTY from time to time, in order to return the
DVB stats.
Tested with a saa7134 card 78:
ASUSTeK P7131 Dual, vendor PCI ID: 1043:4862
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
[bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
Runtime suspend during driver probe and removal can cause problems.
The driver's runtime_suspend or runtime_resume callbacks may invoked
before the driver has finished binding to the device or after the
driver has unbound from the device.
This problem shows up with the sd and sr drivers, and can cause disk
or CD/DVD drives to become unusable as a result. The fix is simple.
The drivers store a pointer to the scsi_disk or scsi_cd structure as
their private device data when probing is finished, so we simply have
to be sure to clear the private data during removal and test it during
runtime suspend/resume.
This fixes <https://bugs.debian.org/801925>.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Paul Menzel <paul.menzel@giantmonkey.de> Reported-by: Erich Schubert <erich@debian.org> Reported-by: Alexandre Rossi <alexandre.rossi@gmail.com> Tested-by: Paul Menzel <paul.menzel@giantmonkey.de> Tested-by: Erich Schubert <erich@debian.org> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
[bwh: Backported to 3.2: drop changes to sr as it doesn't support runtime PM] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
The code within wait_event_interruptible() is called with
!TASK_RUNNING, so mustn't call any functions that can sleep,
like mutex_lock().
Since we re-check the list_empty() in a loop after the wait,
it's safe to simply use list_empty() without locking.
This bug has existed forever, but was only discovered now
because all userspace implementations, including the default
'rfkill' tool, use poll() or select() to get a readable fd
before attempting to read.
Some early controllers incorrectly reported zero ports in PORTS_IMPL
register and the ahci driver fabricates PORTS_IMPL from the number of
ports in those cases. This hasn't mattered but with the new nvme
controllers there are cases where zero PORTS_IMPL is valid and should
be honored.
Disable the workaround for >= AHCI 1.3.
Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/g/CALCETrU7yMvXEDhjAUShoHEhDwifJGapdw--BKxsP0jmjKGmRw@mail.gmail.com Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[wt: file is drivers/ata/ahci.c in 2.6.32] Signed-off-by: Willy Tarreau <w@1wt.eu>
A Root Port's AER structure (rpc) contains a queue of events. aer_irq()
enqueues AER status information and schedules aer_isr() to dequeue and
process it. When we remove a device, aer_remove() waits for the queue to
be empty, then frees the rpc struct.
But aer_isr() references the rpc struct after dequeueing and possibly
emptying the queue, which can cause a use-after-free error as in the
following scenario with two threads, aer_isr() on the left and a
concurrent aer_remove() on the right:
Thread A Thread B
-------- --------
aer_irq():
rpc->prod_idx++
aer_remove():
wait_event(rpc->prod_idx == rpc->cons_idx)
# now blocked until queue becomes empty
aer_isr(): # ...
rpc->cons_idx++ # unblocked because queue is now empty
... kfree(rpc)
mutex_unlock(&rpc->rpc_mutex)
To prevent this problem, use flush_work() to wait until the last scheduled
instance of aer_isr() has completed before freeing the rpc struct in
aer_remove().
I reproduced this use-after-free by flashing a device FPGA and
re-enumerating the bus to find the new device. With SLUB debug, this
crashes with 0x6b bytes (POISON_FREE, the use-after-free magic number) in
GPR25:
[bhelgaas: changelog, stable tag] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[wt: in 2.6.32, kfree() is called from aer_delete_rootport()] Signed-off-by: Willy Tarreau <w@1wt.eu>
Dmitry reported a struct pid leak detected by a syzkaller program.
Bug happens in unix_stream_recvmsg() when we break the loop when a
signal is pending, without properly releasing scm.
Fixes: b3ca9b02b007 ("net: fix multithreaded signal handling in unix recv routines") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Rainer Weikusat <rweikusat@mobileactivedefense.com> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Ben Hutchings <ben@decadent.org.uk>
[wt: note, according to Rainer & Ben the bug was really introduced in
2.5.65, not by the commit mentionned in Fixes. 2.6.32 uses siocb->scm
instead of scm] Signed-off-by: Willy Tarreau <w@1wt.eu>
Ben Hutchings [Sat, 13 Feb 2016 18:42:26 +0000 (18:42 +0000)]
pipe: Fix buffer offset after partially failed read
Quoting the RHEL advisory:
> It was found that the fix for CVE-2015-1805 incorrectly kept buffer
> offset and buffer length in sync on a failed atomic read, potentially
> resulting in a pipe buffer state corruption. A local, unprivileged user
> could use this flaw to crash the system or leak kernel memory to user
> space. (CVE-2016-0774, Moderate)
The same flawed fix was applied to stable branches from 2.6.32.y to
3.14.y inclusive, and I was able to reproduce the issue on 3.2.y.
We need to give pipe_iov_copy_to_user() a separate offset variable
and only update the buffer offset if it succeeds.
References: https://rhn.redhat.com/errata/RHSA-2016-0103.html Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
We used to protect against overflow, but rather than return an error, do
what read/write does, namely to limit the total size to MAX_RW_COUNT.
This is not only more consistent, but it also means that any broken
low-level read/write routine that still keeps counts in 'int' can't
break.
We had for some reason overlooked the AIO interface, and it didn't use
the proper rw_verify_area() helper function that checks (for example)
mandatory locking on the file, and that the size of the access doesn't
cause us to overflow the provided offset limits etc.
Instead, AIO did just the security_file_permission() thing (that
rw_verify_area() also does) directly.
This fixes it to do all the proper helper functions, which not only
means that now mandatory file locking works with AIO too, we can
actually remove lines of code.
Willy Tarreau [Mon, 29 Feb 2016 19:34:15 +0000 (20:34 +0100)]
l2tp: fix another panic in pppol2tp
Commit 3feec9095d1 ("l2tp: Fix oops in pppol2tp_xmit") was backported
into 2.6.32.16 to fix a possible null deref in pppol2tp. But the same
still exists in pppol2tp_sendmsg() possibly causing the same crash.
Note that this bug doesn't appear to have any other impact than crashing
the system, as the dereferenced pointer is only used to test a value
against a 3-bit mask, so it can hardly be abused for anything except
leaking one third of a bit of memory.
This issue doesn't exist upstream because the code was replaced in 2.6.35
and the new function l2tp_xmit_skb() performs the appropriate check.
Reported-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
Dmitry reported that he was able to reproduce the WARN_ON_ONCE that
fires in locks_free_lock_context when the flc_posix list isn't empty.
The problem turns out to be that we're basically rebuilding the
file_lock from scratch in fcntl_setlk when we discover that the setlk
has raced with a close. If the l_whence field is SEEK_CUR or SEEK_END,
then we may end up with fl_start and fl_end values that differ from
when the lock was initially set, if the file position or length of the
file has changed in the interim.
Fix this by just reusing the same lock request structure, and simply
override fl_type value with F_UNLCK as appropriate. That ensures that
we really are unlocking the lock that was initially set.
While we're there, make sure that we do pop a WARN_ON_ONCE if the
removal ever fails. Also return -EBADF in this event, since that's
what we would have returned if the close had happened earlier.
Cc: Alexander Viro <viro@zeniv.linux.org.uk> Fixes: c293621bbf67 (stale POSIX lock handling) Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Acked-by: "J. Bruce Fields" <bfields@fieldses.org>
[bwh: Backported to 3.2: s/i_flctx->flc_posix/inode->i_flock/ in comments] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
The value returned by sys_personality has type "long int".
It is saved to a variable of type "int", which is not a problem
yet because the type of task_struct->pesonality is "unsigned int".
The problem is the sign extension from "int" to "long int"
that happens on return from sys_sparc64_personality.
For example, a userspace call personality((unsigned) -EINVAL) will
result to any subsequent personality call, including absolutely
harmless read-only personality(0xffffffff) call, failing with
errno set to EINVAL.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
There are a couple of nasty truncation bugs lurking in the pageattr
code that can be triggered when mapping EFI regions, e.g. when we pass
a cpa->pgd pointer. Because cpa->numpages is a 32-bit value, shifting
left by PAGE_SHIFT will truncate the resultant address to 32-bits.
Viorel-CÄ\83tÄ\83lin managed to trigger this bug on his Dell machine that
provides a ~5GB EFI region which requires 1236992 pages to be mapped.
When calling populate_pud() the end of the region gets calculated
incorrectly in the following buggy expression,
end = start + (cpa->numpages << PAGE_SHIFT);
And only 188416 pages are mapped. Next, populate_pud() gets invoked
for a second time because of the loop in __change_page_attr_set_clr(),
only this time no pages get mapped because shifting the remaining
number of pages (1048576) by PAGE_SHIFT is zero. At which point the
loop in __change_page_attr_set_clr() spins forever because we fail to
map progress.
Hitting this bug depends very much on the virtual address we pick to
map the large region at and how many pages we map on the initial run
through the loop. This explains why this issue was only recently hit
with the introduction of commit
a5caa209ba9c ("x86/efi: Fix boot crash by mapping EFI memmap
entries bottom-up at runtime, instead of top-down")
It's interesting to note that safe uses of cpa->numpages do exist in
the pageattr code. If instead of shifting ->numpages we multiply by
PAGE_SIZE, no truncation occurs because PAGE_SIZE is a UL value, and
so the result is unsigned long.
To avoid surprises when users try to convert very large cpa->numpages
values to addresses, change the data type from 'int' to 'unsigned
long', thereby making it suitable for shifting by PAGE_SHIFT without
any type casting.
The alternative would be to make liberal use of casting, but that is
far more likely to cause problems in the future when someone adds more
code and fails to cast properly; this bug was difficult enough to
track down in the first place.
Reported-and-tested-by: Viorel-CÄ\83tÄ\83lin RÄ\83piÈ\9beanu <rapiteanu.catalin@gmail.com> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Link: https://bugzilla.kernel.org/show_bug.cgi?id=110131 Link: http://lkml.kernel.org/r/1454067370-10374-1-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
When switch_mm() activates a new PGD, it also sets a bit that
tells other CPUs that the PGD is in use so that TLB flush IPIs
will be sent. In order for that to work correctly, the bit
needs to be visible prior to loading the PGD and therefore
starting to fill the local TLB.
Document all the barriers that make this work correctly and add
a couple that were missing.
Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 2.6.32:
- There's no flush_tlb_mm_range(), only flush_tlb_mm() which does not use
INVLPG
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
ioctl(TIOCGETD) retrieves the line discipline id directly from the
ldisc because the line discipline id (c_line) in termios is untrustworthy;
userspace may have set termios via ioctl(TCSETS*) without actually
changing the line discipline via ioctl(TIOCSETD).
However, directly accessing the current ldisc via tty->ldisc is
unsafe; the ldisc ptr dereferenced may be stale if the line discipline
is changing via ioctl(TIOCSETD) or hangup.
Wait for the line discipline reference (just like read() or write())
to retrieve the "current" line discipline id.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
[bwh: Backported to 2.6.32: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
Commit ed5a377d87dc ("sctp: translate host order to network order when
setting a hmacid") corrected the hmacid byte-order when setting a hmacid.
but the same issue also exists on getting a hmacid.
We fix it by changing hmacids to host order when users get them with
getsockopt.
Fixes: Commit ed5a377d87dc ("sctp: translate host order to network order when setting a hmacid") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
A case can occur when sctp_accept() is called by the user during
a heartbeat timeout event after the 4-way handshake. Since
sctp_assoc_migrate() changes both assoc->base.sk and assoc->ep, the
bh_sock_lock in sctp_generate_heartbeat_event() will be taken with
the listening socket but released with the new association socket.
The result is a deadlock on any future attempts to take the listening
socket lock.
Note that this race can occur with other SCTP timeouts that take
the bh_lock_sock() in the event sctp_accept() is called.
=====================================
[ BUG: bad unlock balance detected! ]
-------------------------------------
CslRx/12087 is trying to release lock (slock-AF_INET) at:
[<ffffffffa01bcae0>] sctp_generate_timeout_event+0x40/0xe0 [sctp]
but there are no more locks to release!
other info that might help us debug this:
2 locks held by CslRx/12087:
#0: (&asoc->timers[i]){+.-...}, at: [<ffffffff8108ce1f>] run_timer_softirq+0x16f/0x3e0
#1: (slock-AF_INET){+.-...}, at: [<ffffffffa01bcac3>] sctp_generate_timeout_event+0x23/0xe0 [sctp]
Ensure the socket taken is also the same one that is released by
saving a copy of the socket before entering the timeout event
critical section.
Signed-off-by: Karl Heiss <kheiss@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 2.6.32:
- Net namespaces are not used
- Keep using sctp_bh_{,un}lock_sock()
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
The visor driver crashes in clie_5_attach() when a specially crafted USB
device without bulk-out endpoint is detected. This fix adds a check that
the device has proper configuration expected by the driver.
While setting the KVM PIT counters in 'kvm_pit_load_count', if
'hpet_legacy_start' is set, the function disables the timer on
channel[0], instead of the respective index 'channel'. This is
because channels 1-3 are not linked to the HPET. Fix the caller
to only activate the special HPET processing for channel 0.
Reported-by: P J P <pjp@fedoraproject.org> Fixes: 0185604c2d82c560dab2f2933a18f797e74ab5a8 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit ef90cf3d0b59e3b1dcfe94d1a241107667e6e96a) Signed-off-by: Willy Tarreau <w@1wt.eu>
Currently if userspace restores the pit counters with a count of 0
on channels 1 or 2 and the guest attempts to read the count on those
channels, then KVM will perform a mod of 0 and crash. This will ensure
that 0 values are converted to 65536 as per the spec.
This is CVE-2015-7513.
Signed-off-by: Andy Honig <ahonig@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 08b8d1a6ccdefd3d517d04c472b7f42f51b3059b) Signed-off-by: Willy Tarreau <w@1wt.eu>
test_pages_in_a_zone() does not account for the possibility of missing
sections in the given pfn range. pfn_valid_within always returns 1 when
CONFIG_HOLES_IN_ZONE is not set, allowing invalid pfns from missing
sections to pass the test, leading to a kernel oops.
Wrap an additional pfn loop with PAGES_PER_SECTION granularity to check
for missing sections before proceeding into the zone-check code.
This also prevents a crash from offlining memory devices with missing
sections. Despite this, it may be a good idea to keep the related patch
'[PATCH 3/3] drivers: memory: prohibit offlining of memory blocks with
missing sections' because missing sections in a memory block may lead to
other problems not covered by the scope of this fix.
Signed-off-by: Andrew Banman <abanman@sgi.com> Acked-by: Alex Thorlton <athorlton@sgi.com> Cc: Russ Anderson <rja@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Greg KH <greg@kroah.com> Cc: Seth Jennings <sjennings@variantweb.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 17f6a291c98199d7ce15a850ce5f548ceef628bc) Signed-off-by: Willy Tarreau <w@1wt.eu>
Add SECTION_ALIGN_UP() and SECTION_ALIGN_DOWN() macro which aligns given
pfn to upper section and lower section boundary accordingly.
Required for the latest memory hotplug support for the Xen balloon driver.
Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[wt: only needed for next patch] Signed-off-by: Willy Tarreau <w@1wt.eu>
ip6addrlbl_get() has never worked. If ip6addrlbl_hold() succeeded,
ip6addrlbl_get() will exit with '-ESRCH'. If ip6addrlbl_hold() failed,
ip6addrlbl_get() will use about to be free ip6addrlbl_entry pointer.
Fix this by inverting ip6addrlbl_hold() check.
Fixes: 2a8cc6c89039 ("[IPV6] ADDRCONF: Support RFC3484 configurable address selection policy table.") Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Cong Wang <cwang@twopensource.com> Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 39b214ba1a357359f9c0be6ef8d21f2e5187567a) Signed-off-by: Willy Tarreau <w@1wt.eu>
On parisc syscalls which are interrupted by signals sometimes failed to
restart and instead returned -ENOSYS which in the worst case lead to
userspace crashes.
A similiar problem existed on MIPS and was fixed by commit e967ef02
("MIPS: Fix restart of indirect syscalls").
On parisc the current syscall restart code assumes that all syscall
callers load the syscall number in the delay slot of the ble
instruction. That's how it is e.g. done in the unistd.h header file:
ble 0x100(%sr2, %r0)
ldi #syscall_nr, %r20
Because of that assumption the current code never restored %r20 before
returning to userspace.
This assumption is at least not true for code which uses the glibc
syscall() function, which instead uses this syntax:
ble 0x100(%sr2, %r0)
copy regX, %r20
where regX depend on how the compiler optimizes the code and register
usage.
This patch fixes this problem by adding code to analyze how the syscall
number is loaded in the delay branch and - if needed - copy the syscall
number to regX prior returning to userspace for the syscall restart.
Signed-off-by: Helge Deller <deller@gmx.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 9f2dcffefc599c424ad1dd402e3a96da60639308) Signed-off-by: Willy Tarreau <w@1wt.eu>
When 32-bit MIPS userspace invokes a syscall indirectly via syscall(number,
arg1, ..., arg7), the kernel looks up the actual syscall based on the given
number, shifts the other arguments to the left, and jumps to the syscall.
If the syscall is interrupted by a signal and indicates it needs to be
restarted by the kernel (by returning ERESTARTNOINTR for example), the
syscall must be called directly, since the number is no longer the first
argument, and the other arguments are now staged for a direct call.
Before shifting the arguments, store the syscall number in pt_regs->regs[2].
This gets copied temporarily into pt_regs->regs[0] after the syscall returns.
If the syscall needs to be restarted, handle_signal()/do_signal() copies the
number back to pt_regs->reg[2], which ends up in $v0 once control returns to
userspace.
Signed-off-by: Ed Swierk <eswierk@skyportsystems.com> Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8929/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 08f865bba9c705aef95268a33393698e5385587e) Signed-off-by: Willy Tarreau <w@1wt.eu>
Commit 8520f38099cc ("USB: change hub initialization sleeps to
delayed_work") changed the hub_activate() routine to make part of it
run in a workqueue. However, the commit failed to take a reference to
the usb_hub structure or to lock the hub interface while doing so. As
a result, if a hub is plugged in and quickly unplugged before the work
routine can run, the routine will try to access memory that has been
deallocated. Or, if the hub is unplugged while the routine is
running, the memory may be deallocated while it is in active use.
This patch fixes the problem by taking a reference to the usb_hub at
the start of hub_activate() and releasing it at the end (when the work
is finished), and by locking the hub interface while the work routine
is running. It also adds a check at the start of the routine to see
if the hub has already been disconnected, in which nothing should be
done.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Alexandru Cornea <alexandru.cornea@intel.com> Tested-by: Alexandru Cornea <alexandru.cornea@intel.com> Fixes: 8520f38099cc ("USB: change hub initialization sleeps to delayed_work") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: add prototype for hub_release() before first use] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 10037421b529bc1fc18994e94e37d745184c4ea9)
[wt: made a few changes :
- adjusted context due to some autopm code being added only in 2.6.33
- no device_{lock,unlock}() in 2.6.32, use up/down(&->sem) instead] Signed-off-by: Willy Tarreau <w@1wt.eu>
The code expects the loop to end with "retries" set to zero but, because
it is a post-op, it will end set to -1. I have fixed this by moving the
decrement inside the loop.
Fixes: 014aa2a3c32e ('USB: ipaq: minor ipaq_open() cleanup.') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 53a68d3f1629de82ddeb4e0882b0727fc230a6f3) Signed-off-by: Willy Tarreau <w@1wt.eu>
The print_insn() function returns strings like "lghi %r1,0". To escape the
'%' character in sprintf() a second '%' is used. For example "lghi %%r1,0"
is converted into "lghi %r1,0".
After print_insn() the output string is passed to printk(). Because format
specifiers like "%r" or "%f" are ignored by printk() this works by chance
most of the time. But for instructions with control registers like
"lctl %c6,%c6,780" this fails because printk() interprets "%c" as
character format specifier.
Fix this problem and escape the '%' characters twice.
For example "lctl %%%%c6,%%%%c6,780" is then converted by sprintf()
into "lctl %%c6,%%c6,780" and by printk() into "lctl %c6,%c6,780".
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[bwh: Backported to 3.2: drop the OPERAND_VR case] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 45f32e359d36dd045e4af0d1bea8bbbafd81eeb7) Signed-off-by: Willy Tarreau <w@1wt.eu>
Fix parent-device reference leak due to SPI-core taking an unnecessary
reference to the parent when allocating the master structure, a
reference that was never released.
Note that driver core takes its own reference to the parent when the
master device is registered.
Fixes: 49dce689ad4e ("spi doesn't need class_device") Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 40ddf30ca43b50019304303949c9b2676cfbd820) Signed-off-by: Willy Tarreau <w@1wt.eu>
When shutting down the device, the struct ser_cardstate must not be
kfree()d immediately after the call to platform_device_unregister()
since the embedded struct platform_device is still in use.
Move the kfree() call to the release method instead.
Signed-off-by: Tilman Schmidt <tilman@imap.cc> Fixes: 2869b23e4b95 ("drivers/isdn/gigaset: new M101 driver (v2)") Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 521e4101aaf46b2f37088453a1e935604cdd7f2a) Signed-off-by: Willy Tarreau <w@1wt.eu>
There are two issue here.
1) cnt starts as maxloop + 1 so all these loops iterate one more time
than intended.
2) At the end of the loop we test for "if (maxloop && !cnt)" but for
the first two loops, we end with cnt equal to -1. Changing this to
a pre-op means we end with cnt set to 0.
Fixes: cae86d4a4e56 ('mISDN: Add driver for Infineon ISDN chipset family') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 7eb2a0151e7c8a95d1be33a923718fb690452c61) Signed-off-by: Willy Tarreau <w@1wt.eu>
A line discipline which does not define a receive_buf() method can
can cause a GPF if data is ever received [1]. Oddly, this was known
to the author of n_tracesink in 2011, but never fixed.
KASAN found that our additional element processing scripts drop off
the end of the VPD page into unallocated space. The reason is that
not every element has additional information but our traversal
routines think they do, leading to them expecting far more additional
information than is present. Fix this by adding a gate to the
traversal routine so that it only processes elements that are expected
to have additional information (list is in SES-2 section 6.1.13.1:
Additional Element Status diagnostic page overview)
Reported-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Tested-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 344d6d02690a650607e6372bce8fe40e647a51b5) Signed-off-by: Willy Tarreau <w@1wt.eu>
Simple enclosure implementations (mostly USB) are allowed to return only
page 8 to every diagnostic query. That really confuses our
implementation because we assume the return is the page we asked for and
end up doing incorrect offsets based on bogus information leading to
accesses outside of allocated ranges. Fix that by checking the page
code of the return and giving an error if it isn't the one we asked for.
This should fix reported bugs with USB storage by simply refusing to
attach to enclosures that behave like this. It's also good defensive
practise now that we're starting to see more USB enclosures.
Reported-by: Andrea Gelmini <andrea.gelmini@gelma.net> Reviewed-by: Ewan D. Milne <emilne@redhat.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 25ef938516d26c3db9cb1f5b927ad7ee95be1022) Signed-off-by: Willy Tarreau <w@1wt.eu>
Some users of rfkill, like NFC and cfg80211, use a dynamic name when
allocating rfkill, in those cases dev_name(). Therefore, the pointer
passed to rfkill_alloc() might not be valid forever, I specifically
found the case that the rfkill name was quite obviously an invalid
pointer (or at least garbage) when the wiphy had been renamed.
Fix this by making a copy of the rfkill name in rfkill_alloc().
Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 6f23bc6f6be370267332a0278a4646126836baee) Signed-off-by: Willy Tarreau <w@1wt.eu>
Using bit fields is dangerous on ppc64/sparc64, as the compiler [1]
uses 64bit instructions to manipulate them.
If the 64bit word includes any atomic_t or spinlock_t, we can lose
critical concurrent changes.
This is happening in af_unix, where unix_sk(sk)->gc_candidate/
gc_maybe_cycle/lock share the same 64bit word.
This leads to fatal deadlock, as one/several cpus spin forever
on a spinlock that will never be available again.
A safer way would be to use a long to store flags.
This way we are sure compiler/arch wont do bad things.
As we own unix_gc_lock spinlock when clearing or setting bits,
we can use the non atomic __set_bit()/__clear_bit().
recursion_level can share the same 64bit location with the spinlock,
as it is set only with this spinlock held.
[1] bug fixed in gcc-4.8.0 :
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52080
Reported-by: Ambrose Feinstein <ambrose@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 2ee9cbe7e7bfe2d36374288b818aa31b2c4981db)
[wt: adjusted context] Signed-off-by: Willy Tarreau <w@1wt.eu>
Dmitry Vyukov reported that SCTP was triggering a WARN on socket destroy
related to disabling sock timestamp.
When SCTP accepts an association or peel one off, it copies sock flags
but forgot to call net_enable_timestamp() if a packet timestamping flag
was copied, leading to extra calls to net_disable_timestamp() whenever
such clones were closed.
The fix is to call net_enable_timestamp() whenever we copy a sock with
that flag on, like tcp does.
Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: SK_FLAGS_TIMESTAMP is newly defined] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit d85242d91610acbe4f905624a5758a01ae7bb32c) Signed-off-by: Willy Tarreau <w@1wt.eu>
Further investigation showed that this can happen when an *odd* number of
fds are being passed over AF_UNIX sockets.
In these cases CMSG_LEN(i * sizeof(int)) and CMSG_SPACE(i * sizeof(int)),
where i is the number of successfully passed fds, differ by 4 bytes due
to the extra CMSG_ALIGN() padding in CMSG_SPACE() to an 8 byte boundary
on 64 bit. The padding is used to align subsequent cmsg headers in the
control buffer.
When the control buffer passed in from the receiver side *lacks* these 4
bytes (e.g. due to buggy/wrong API usage), then msg->msg_controllen will
overflow in scm_detach_fds():
int cmlen = CMSG_LEN(i * sizeof(int)); <--- cmlen w/o tail-padding
err = put_user(SOL_SOCKET, &cm->cmsg_level);
if (!err)
err = put_user(SCM_RIGHTS, &cm->cmsg_type);
if (!err)
err = put_user(cmlen, &cm->cmsg_len);
if (!err) {
cmlen = CMSG_SPACE(i * sizeof(int)); <--- cmlen w/ 4 byte extra tail-padding
msg->msg_control += cmlen;
msg->msg_controllen -= cmlen; <--- iff no tail-padding space here ...
} ... wrap-around
F.e. it will wrap to a length of 18446744073709551612 bytes in case the
receiver passed in msg->msg_controllen of 20 bytes, and the sender
properly transferred 1 fd to the receiver, so that its CMSG_LEN results
in 20 bytes and CMSG_SPACE in 24 bytes.
In case of MSG_CMSG_COMPAT (scm_detach_fds_compat()), I haven't seen an
issue in my tests as alignment seems always on 4 byte boundary. Same
should be in case of native 32 bit, where we end up with 4 byte boundaries
as well.
In practice, passing msg->msg_controllen of 20 to recvmsg() while receiving
a single fd would mean that on successful return, msg->msg_controllen is
being set by the kernel to 24 bytes instead, thus more than the input
buffer advertised. It could f.e. become an issue if such application later
on zeroes or copies the control buffer based on the returned msg->msg_controllen
elsewhere.
Maximum number of fds we can send is a hard upper limit SCM_MAX_FD (253).
Going over the code, it seems like msg->msg_controllen is not being read
after scm_detach_fds() in scm_recv() anymore by the kernel, good!
Relevant recvmsg() handler are unix_dgram_recvmsg() (unix_seqpacket_recvmsg())
and unix_stream_recvmsg(). Both return back to their recvmsg() caller,
and ___sys_recvmsg() places the updated length, that is, new msg_control -
old msg_control pointer into msg->msg_controllen (hence the 24 bytes seen
in the example).
Long time ago, Wei Yongjun fixed something related in commit 1ac70e7ad24a
("[NET]: Fix function put_cmsg() which may cause usr application memory
overflow").
RFC3542, section 20.2. says:
The fields shown as "XX" are possible padding, between the cmsghdr
structure and the data, and between the data and the next cmsghdr
structure, if required by the implementation. While sending an
application may or may not include padding at the end of last
ancillary data in msg_controllen and implementations must accept both
as valid. On receiving a portable application must provide space for
padding at the end of the last ancillary data as implementations may
copy out the padding at the end of the control message buffer and
include it in the received msg_controllen. When recvmsg() is called
if msg_controllen is too small for all the ancillary data items
including any trailing padding after the last item an implementation
may set MSG_CTRUNC.
Since we didn't place MSG_CTRUNC for already quite a long time, just do
the same as in 1ac70e7ad24a to avoid an overflow.
Btw, even man-page author got this wrong :/ See db939c9b26e9 ("cmsg.3: Fix
error in SCM_RIGHTS code sample"). Some people must have copied this (?),
thus it got triggered in the wild (reported several times during boot by
David and HacKurx).
No Fixes tag this time as pre 2002 (that is, pre history tree).
Reported-by: David Sterba <dave@jikos.cz> Reported-by: HacKurx <hackurx@gmail.com> Cc: PaX Team <pageexec@freemail.hu> Cc: Emese Revfy <re.emese@gmail.com> Cc: Brad Spengler <spender@grsecurity.net> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: Eric Dumazet <edumazet@google.com> Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 831a2a17da39d93cf68981ff99cce5d31551044b) Signed-off-by: Willy Tarreau <w@1wt.eu>
His program is specifically attempting a Cross SYN TCP exchange,
that we support (for the pleasure of hackers ?), but it looks we
lack proper tcp->copied_seq initialization.
Thanks again Dmitry for your report and testings.
Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 6cfa9781d3bf950eed455369966bbdf9d05871c5) Signed-off-by: Willy Tarreau <w@1wt.eu>
We encountered a panic on boot in ipmi_si on a dell per320 due to an
uninitialized timer as follows.
static int smi_start_processing(void *send_info,
ipmi_smi_t intf)
{
/* Try to claim any interrupts. */
if (new_smi->irq_setup)
new_smi->irq_setup(new_smi);
--> IRQ arrives here and irq handler tries to modify uninitialized timer
which triggers BUG_ON(!timer->function) in __mod_timer().
Because wakeups can (fundamentally) be late, a task might not be in
the expected state. Therefore testing against a task's state is racy,
and can yield false positives.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: oleg@redhat.com Fixes: 9067ac85d533 ("wake_up_process() should be never used to wakeup a TASK_STOPPED/TRACED task") Link: http://lkml.kernel.org/r/1448933660-23082-1-git-send-email-sasha.levin@oracle.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 0e796c1b57fdd97fc040b0b78ff7fea6c0a4a39d) Signed-off-by: Willy Tarreau <w@1wt.eu>
When a multicast group is joined on a socket, a struct ip_mc_socklist
is appended to the sockets mc_list containing information about the
joined group.
If the interface is hot unplugged, this entry becomes stale. Prior to
commit 52ad353a5344f ("igmp: fix the problem when mc leave group") it
was possible to remove the stale entry by performing a
IP_DROP_MEMBERSHIP, passing either the old ifindex or ip address on
the interface. However, this fix enforces that the interface must
still exist. Thus with time, the number of stale entries grows, until
sysctl_igmp_max_memberships is reached and then it is not possible to
join and more groups.
The previous patch fixes an issue where a IP_DROP_MEMBERSHIP is
performed without specifying the interface, either by ifindex or ip
address. However here we do supply one of these. So loosen the
restriction on device existence to only apply when the interface has
not been specified. This then restores the ability to clean up the
stale entries.
Signed-off-by: Andrew Lunn <andrew@lunn.ch> Fixes: 52ad353a5344f "(igmp: fix the problem when mc leave group") Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit b1fa852672fb1ea4b0e34bfa1136bb65dba66151) Signed-off-by: Willy Tarreau <w@1wt.eu>
The N_X25 line discipline may access the previous line discipline's closed
and already-freed private data on open [1].
The tty->disc_data field _never_ refers to valid data on entry to the
line discipline's open() method. Rather, the ldisc is expected to
initialize that field for its own use for the lifetime of the instance
(ie. from open() to close() only).
Reported-and-tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 485274cf9a69504cf4a7ef182c508f3541eee84e) Signed-off-by: Willy Tarreau <w@1wt.eu>
If we pass in an empty nfs_fattr struct to nfs_update_inode, it will
(correctly) not update any of the attributes, but it then clears the
NFS_INO_INVALID_ATTR flag, which indicates that the attributes are
up to date. Don't clear the flag if the fattr struct has no valid
attrs to apply.
Reviewed-by: Steve French <steve.french@primarydata.com> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit ddab0155aa9589600861e3f65d505982b719496a) Signed-off-by: Willy Tarreau <w@1wt.eu>
In ext4, the bottom two bits of {a,c,m}time_extra are used to extend
the {a,c,m}time fields, deferring the year 2038 problem to the year
2446.
When decoding these extended fields, for times whose bottom 32 bits
would represent a negative number, sign extension causes the 64-bit
extended timestamp to be negative as well, which is not what's
intended. This patch corrects that issue, so that the only negative
{a,c,m}times are those between 1901 and 1970 (as per 32-bit signed
timestamps).
Some older kernels might have written pre-1970 dates with 1,1 in the
extra bits. This patch treats those incorrectly-encoded dates as
pre-1970, instead of post-2311, until kernel 4.20 is released.
Hopefully by then e2fsck will have fixed up the bad data.
Also add a comment explaining the encoding of ext4's extra {a,c,m}time
bits.
Signed-off-by: David Turner <novalis@novalis.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reported-by: Mark Harris <mh8928@yahoo.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=23732 Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 6dfd5f6abf1825fc351f663bf630603f9b78251b) Signed-off-by: Willy Tarreau <w@1wt.eu>
The following test program from Dmitry can cause softlockups or RCU
stalls as it copies 1GB from tmpfs into eventfd and we don't have any
scheduling point at that path in sendfile(2) implementation:
int r1 = eventfd(0, 0);
int r2 = memfd_create("", 0);
unsigned long n = 1<<30;
fallocate(r2, 0, 0, n);
sendfile(r1, r2, 0, n);
Add cond_resched() into __splice_from_pipe() to fix the problem.
CC: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 47ae562efbd0fd8440959304915291865b945c67) Signed-off-by: Willy Tarreau <w@1wt.eu>
The thing got broken back in 2002 - sysvfs does *not* have inline
symlinks; even short ones have bodies stored in the first block
of file. sysv_symlink() handles that correctly; unfortunately,
attempting to look an existing symlink up will end up confusing
them for inline symlinks, and interpret the block number containing
the body as the body itself.
Nobody has noticed until now, which says something about the level
of testing sysvfs gets ;-/
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2:
- Adjust context
- Also delete unused sysv_fast_symlink_inode_operations] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 081c769778f7a41f4eb3d633df26ad572575c980) Signed-off-by: Willy Tarreau <w@1wt.eu>
I got a report about unkillable task eating CPU. Further
investigation shows, that the problem is in the fuse_fill_write_pages()
function. If iov's first segment has zero length, we get an infinite
loop, because we never reach iov_iter_advance() call.
Fix this by calling iov_iter_advance() before repeating an attempt to
copy data from userspace.
A similar problem is described in 124d3b7041f ("fix writev regression:
pan hanging unkillable and un-straceable"). If zero-length segmend
is followed by segment with invalid address,
iov_iter_fault_in_readable() checks only first segment (zero-length),
iov_iter_copy_from_user_atomic() skips it, fails at second and
returns zero -> goto again without skipping zero-length segment.
Patch calls iov_iter_advance() before goto again: we'll skip zero-length
segment at second iteraction and iov_iter_fault_in_readable() will detect
invalid address.
Special thanks to Konstantin Khlebnikov, who helped a lot with the commit
description.
Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Maxim Patlasov <mpatlasov@parallels.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Roman Gushchin <klamm@yandex-team.ru> Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Fixes: ea9b9907b82a ("fuse: implement perform_write") Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit a5b234167a1ff46f311f5835828eec2f971b9bb4)
[wt: adjusted context, as commit 478e0841b from 3.1 was never backported
to call mark_page_accessed() eventhough it seems it should have been] Signed-off-by: Willy Tarreau <w@1wt.eu>
now sctp auth cannot work well when setting a hmacid manually, which
is caused by that we didn't use the network order for hmacid, so fix
it by adding the transformation in sctp_auth_ep_set_hmacs.
even we set hmacid with the network order in userspace, it still
can't work, because of this condition in sctp_auth_ep_set_hmacs():
if (id > SCTP_AUTH_HMAC_ID_MAX)
return -EOPNOTSUPP;
so this wasn't working before and thus it won't break compatibility.
Fixes: 65b07e5d0d09 ("[SCTP]: API updates to suport SCTP-AUTH extensions.") Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 98d37e7fed9568f37d4a4a150a3773cfafef91ed) Signed-off-by: Willy Tarreau <w@1wt.eu>
Docbook does not like the definition of macros inside a field declaration
and adds a warning. Move the definition out.
Fixes: 79462ad02e86180 ("net: add validation for the socket syscall protocol argument") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: keep open-coding U8_MAX] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 35da6d62b608fd3beb576d72e48e2bc866d714c9)
[wt: adjusted context] Signed-off-by: Willy Tarreau <w@1wt.eu>
AF_INET, AF_INET6 sockets actually only support 8-bit protocol
identifiers. inet_sock's skc_protocol field thus is sized accordingly,
thus larger protocol identifiers simply cut off the higher bits and
store a zero in the protocol fields.
This could lead to e.g. NULL function pointer because as a result of
the cut off inet_num is zero and we call down to inet_autobind, which
is NULL for raw sockets.
I found no particular commit which introduced this problem.
CVE: CVE-2015-8543 Cc: Cong Wang <cwang@twopensource.com> Reported-by: é\83æ°¸å\88\9a <guoyonggang@360.cn> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 2.6.32: open-code U8_MAX; adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
There's a race between keyctl_read() and keyctl_revoke(). If the revoke
happens between keyctl_read() checking the validity of a key and the key's
semaphore being taken, then the key type read method will see a revoked key.
This causes a problem for the user-defined key type because it assumes in
its read method that there will always be a payload in a non-revoked key
and doesn't check for a NULL pointer.
Fix this by making keyctl_read() check the validity of a key after taking
semaphore instead of before.
I think the bug was introduced with the original keyrings code.
This was discovered by a multithreaded test program generated by syzkaller
(http://github.com/google/syzkaller). Here's a cleaned up version:
Backport of this upstream commit into stable kernels : 89c22d8c3b27 ("net: Fix skb csum races when peeking")
exposed a bug in udp stack vs MSG_PEEK support, when user provides
a buffer smaller than skb payload.
In this case,
skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr),
msg->msg_iov);
returns -EFAULT.
This bug does not happen in upstream kernels since Al Viro did a great
job to replace this into :
skb_copy_and_csum_datagram_msg(skb, sizeof(struct udphdr), msg);
This variant is safe vs short buffers.
For the time being, instead reverting Herbert Xu patch and add back
skb->ip_summed invalid changes, simply store the result of
udp_lib_checksum_complete() so that we avoid computing the checksum a
second time, and avoid the problematic
skb_copy_and_csum_datagram_iovec() call.
This patch can be applied on recent kernels as it avoids a double
checksumming, then backported to stable kernels as a bug fix.
Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 18a6eba2eabbcb50a78210b16f7dd43d888a537b) Signed-off-by: Willy Tarreau <w@1wt.eu>
Willy Tarreau [Sat, 23 Jan 2016 10:16:20 +0000 (11:16 +0100)]
Revert "net: add length argument to skb_copy_and_csum_datagram_iovec"
This reverts commit c507639ba963bb47e3f515670a7cace76af76ab6.
As reported by Michal Kubecek, this fix doesn't handle truncated
reads correctly. Next patch from Eric fixes it better.
Rainer Weikusat <rweikusat@mobileactivedefense.com> writes:
An AF_UNIX datagram socket being the client in an n:1 association with
some server socket is only allowed to send messages to the server if the
receive queue of this socket contains at most sk_max_ack_backlog
datagrams. This implies that prospective writers might be forced to go
to sleep despite none of the message presently enqueued on the server
receive queue were sent by them. In order to ensure that these will be
woken up once space becomes again available, the present unix_dgram_poll
routine does a second sock_poll_wait call with the peer_wait wait queue
of the server socket as queue argument (unix_dgram_recvmsg does a wake
up on this queue after a datagram was received). This is inherently
problematic because the server socket is only guaranteed to remain alive
for as long as the client still holds a reference to it. In case the
connection is dissolved via connect or by the dead peer detection logic
in unix_dgram_sendmsg, the server socket may be freed despite "the
polling mechanism" (in particular, epoll) still has a pointer to the
corresponding peer_wait queue. There's no way to forcibly deregister a
wait queue with epoll.
Based on an idea by Jason Baron, the patch below changes the code such
that a wait_queue_t belonging to the client socket is enqueued on the
peer_wait queue of the server whenever the peer receive queue full
condition is detected by either a sendmsg or a poll. A wake up on the
peer queue is then relayed to the ordinary wait queue of the client
socket via wake function. The connection to the peer wait queue is again
dissolved if either a wake up is about to be relayed or the client
socket reconnects or a dead peer is detected or the client socket is
itself closed. This enables removing the second sock_poll_wait from
unix_dgram_poll, thus avoiding the use-after-free, while still ensuring
that no blocked writer sleeps forever.
Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com> Fixes: ec0d215f9420 ("af_unix: fix 'poll for write'/connected DGRAM sockets") Reviewed-by: Jason Baron <jbaron@akamai.com> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 2.6.32:
- Access sk_sleep directly, not through sk_sleep() function
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
Sasha's found a NULL pointer dereference in the RDS connection code when
sending a message to an apparently unbound socket. The problem is caused
by the code checking if the socket is bound in rds_sendmsg(), which checks
the rs_bound_addr field without taking a lock on the socket. This opens a
race where rs_bound_addr is temporarily set but where the transport is not
in rds_bind(), leading to a NULL pointer dereference when trying to
dereference 'trans' in __rds_conn_create().
Vegard wrote a reproducer for this issue, so kindly ask him to share if
you're interested.
I cannot reproduce the NULL pointer dereference using Vegard's reproducer
with this patch, whereas I could without.
Complete earlier incomplete fix to CVE-2015-6937:
74e98eb08588 ("RDS: verify the underlying transport exists before creating a connection")
Cc: David S. Miller <davem@davemloft.net> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Reviewed-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
Currently slhc_init() treats out-of-range values of rslots and tslots
as equivalent to 0, except that if tslots is too large it will
dereference a null pointer (CVE-2015-7799).
Add a range-check at the top of the function and make it return an
ERR_PTR() on error instead of NULL. Change the callers accordingly.
Compile-tested only.
Reported-by: é\83æ°¸å\88\9a <guoyonggang@360.cn>
References: http://article.gmane.org/gmane.comp.security.oss.general/17908 Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 2.6.32: adjust filenames, context, indentation] Signed-off-by: Willy Tarreau <w@1wt.eu>
We need to wait for the flying timers, since we
are going to free the mrtable right after it.
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Ben Hutchings <ben@decadent.org.uk>
[ wt: 2.6.32 has a single table hence a single timer. ip6_mr_init() has
the same del_timer() call on the error path, but we don't need to
change it since at this point the timer hasn't been started yet ] Signed-off-by: Willy Tarreau <w@1wt.eu>
projects / linux-stable / log