Fixes: c9b60788fc76 ("f2fs: fix to do sanity check with block address in main area") Cc: <stable@vger.kernel.org> # 4.19+ Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Malicious code can attempt to free buffers using the BC_FREE_BUFFER
ioctl to binder. There are protections against a user freeing a buffer
while in use by the kernel, however there was a window where
BC_FREE_BUFFER could be used to free a recently allocated buffer that
was not completely initialized. This resulted in a use-after-free
detected by KASAN with a malicious test program.
This window is closed by setting the buffer's allow_user_free attribute
to 0 when the buffer is allocated or when the user has previously freed
it instead of waiting for the caller to set it. The problem was that
when the struct buffer was recycled, allow_user_free was stale and set
to 1 allowing a free to go through.
drivers/misc/mic/scif/scif_rma.c: In function 'scif_create_remote_lookup':
drivers/misc/mic/scif/scif_rma.c:373:25: warning:
variable 'vmalloc_num_pages' set but not used [-Wunused-but-set-variable]
'vmalloc_num_pages' should be used to determine if the address is
within the vmalloc range.
This is a longstanding issue: if the vmbus upper-layer drivers try to
consume too many GPADLs, the host may return with an error
0xC0000044 (STATUS_QUOTA_EXCEEDED), but currently we forget to check
the creation_status, and hence we can pass an invalid GPADL handle
into the OPEN_CHANNEL message, and get an error code 0xc0000225 in
open_info->response.open_result.status, and finally we hang in
vmbus_open() -> "goto error_free_info" -> vmbus_teardown_gpadl().
With this patch, we can exit gracefully on STATUS_QUOTA_EXCEEDED.
Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: stable@vger.kernel.org Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We changed the key of swap cache tree from swp_entry_t.val to
swp_offset. We need to do so in shmem_replace_page() as well.
Hugh said:
"shmem_replace_page() has been wrong since the day I wrote it: good
enough to work on swap "type" 0, which is all most people ever use
(especially those few who need shmem_replace_page() at all), but
broken once there are any non-0 swp_type bits set in the higher order
bits"
Link: http://lkml.kernel.org/r/20181121215442.138545-1-yuzhao@google.com Fixes: f6ab1f7f6b2d ("mm, swap: use offset of swap entry as key of swap cache") Signed-off-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Matthew Wilcox <willy@infradead.org> Acked-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> [4.9+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, we enable the device before we enable the device trigger. At
high frequencies, this can cause interrupts that don't yet have a poll
function associated with them and are thus treated as spurious. At high
frequencies with level interrupts, this can even cause an interrupt storm
of repeated spurious interrupts (~100,000 on my Beagleboard with the
LSM9DS1 magnetometer). If these repeat too much, the interrupt will get
disabled and the device will stop functioning.
To prevent these problems, enable the device prior to enabling the device
trigger, and disable the divec prior to disabling the trigger. This means
there's no window of time during which the device creates interrupts but we
have no trigger to answer them.
Fixes: 90efe055629 ("iio: st_sensors: harden interrupt handling") Signed-off-by: Martin Kelly <martin@martingkelly.com> Tested-by: Denis Ciocca <denis.ciocca@st.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cherry G230 Stream 2.0 (G85-231) and 3.0 (G85-232) need this quirk to
function correctly. This fixes a but where double pressing numlock locks
up the device completely with need to replug the keyboard.
Signed-off-by: Michael Niewöhner <linux@mniewoehner.de> Tested-by: Michael Niewöhner <linux@mniewoehner.de> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With Androidx86 8.1, wificond returns "failed to get
nl80211_sta_info_tx_failed" and wificondControl returns "Invalid signal
poll result from wificond". The fix is to OR sinfo->filled with
BIT_ULL(NL80211_STA_INFO_TX_FAILED).
This missing bit is apparently not needed with NetworkManager, but it
does no harm in that case.
The compatibility ioctl wrapper for VCHIQ_IOC_AWAIT_COMPLETION assumes that
the native ioctl always uses a message buffer and decrements msgbufcount.
Certain message types do not use a message buffer and in this case
msgbufcount is not decremented, and completion->header for the message is
NULL. Because the wrapper unconditionally decrements msgbufcount, the
calling process may assume that a message buffer has been used even when
it has not.
This results in a memory leak in the userspace code that interfaces with
this driver. When msgbufcount is decremented, the userspace code assumes
that the buffer can be freed though the reference in completion->header,
which cannot happen when the reference is NULL.
This patch causes the wrapper to only decrement msgbufcount when the
native ioctl decrements it. Note that we cannot simply copy the native
ioctl's value of msgbufcount, because the wrapper only retrieves messages
from the native ioctl one at a time, while userspace may request multiple
messages.
See https://github.com/raspberrypi/linux/pull/2703 for more discussion of
this patch.
Fixes: 5569a1260933 ("staging: vchiq_arm: Add compatibility wrappers for ioctls") Signed-off-by: Ben Wolsieffer <benwolsieffer@gmail.com> Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Josef Bacik [Mon, 3 Dec 2018 11:06:57 +0000 (13:06 +0200)]
btrfs: release metadata before running delayed refs
We want to release the unused reservation we have since it refills the
delayed refs reserve, which will make everything go smoother when
running the delayed refs if we're short on our reservation.
CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
of_dma_controller_free() was not called on module onloading.
This lead to a soft lockup:
watchdog: BUG: soft lockup - CPU#0 stuck for 23s!
Modules linked in: at_hdmac [last unloaded: at_hdmac]
when of_dma_request_slave_channel() tried to call ofdma->of_dma_xlate().
The leak was found when opening/closing a serial port a great number of
time, increasing kmalloc-32 in slabinfo.
Each time the port was opened, dma_request_slave_channel() was called.
Then, in at_dma_xlate(), atslave was allocated with devm_kzalloc() and
never freed. (Well, it was free at module unload, but that's not what we
want).
So, here, kzalloc is more suited for the job since it has to be freed in
atc_free_chan_resources().
The Coreboot version on veyron ChromeOS devices seems to ignore
memory@0 nodes when updating the available memory and instead
inserts another memory node without the address.
This leads to 4GB systems only ever be using 2GB as the memory@0
node takes precedence. So remove the @0 for veyron devices.
Fixes: 0b639b815f15 ("ARM: dts: rockchip: Add missing unit name to memory nodes in rk3288 boards") Cc: stable@vger.kernel.org Reported-by: Heikki Lindholm <holin@iki.fi> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The function ext2_xattr_set calls brelse(bh) to drop the reference count
of bh. After that, bh may be freed. However, following brelse(bh),
it reads bh->b_data via macro HDR(bh). This may result in a
use-after-free bug. This patch moves brelse(bh) after reading field.
CC: stable@vger.kernel.org Signed-off-by: Pan Bian <bianpan2016@163.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some spurious calls of snd_free_pages() have been overlooked and
remain in the error paths of sparc cs4231 driver code. Since
runtime->dma_area is managed by the PCM core helper, we shouldn't
release manually.
The procedure for adding a user control element has some window opened
for race against the concurrent removal of a user element. This was
caught by syzkaller, hitting a KASAN use-after-free error.
This patch addresses the bug by wrapping the whole procedure to add a
user control element with the card->controls_rwsem, instead of only
around the increment of card->user_ctl_count.
This required a slight code refactoring, too. The function
snd_ctl_add() is split to two parts: a core function to add the
control element and a part calling it. The former is called from the
function for adding a user control element inside the controls_rwsem.
One change to be noted is that snd_ctl_notify() for adding a control
element gets called inside the controls_rwsem as well while it was
called outside the rwsem. But this should be OK, as snd_ctl_notify()
takes another (finer) rwlock instead of rwsem, and the call of
snd_ctl_notify() inside rwsem is already done in another code path.
The function snd_ac97_put_spsa() gets the bit shift value from the
associated private_value, but it extracts too much; the current code
extracts 8 bit values in bits 8-15, but this is a combination of two
nibbles (bits 8-11 and bits 12-15) for left and right shifts.
Due to the incorrect bits extraction, the actual shift may go beyond
the 32bit value, as spotted recently by UBSAN check:
UBSAN: Undefined behaviour in sound/pci/ac97/ac97_codec.c:836:7
shift exponent 68 is too large for 32-bit type 'int'
This patch fixes the shift value extraction by masking the properly
with 0x0f instead of 0xff.
Some spurious calls of snd_free_pages() have been overlooked and
remain in the error paths of wss driver code. Since runtime->dma_area
is managed by the PCM core helper, we shouldn't release manually.
commit e259221763a40403d5bb232209998e8c45804ab8 ("fs: simplify the
generic_write_sync prototype") reworked callers of generic_write_sync(),
and ended up dropping the error return for the directio path. Prior to
that commit, in dio_complete(), an error would be bubbled up the stack,
but after that commit, errors passed on to dio_complete were eaten up.
This was reported on the list earlier, and a fix was proposed in
https://lore.kernel.org/lkml/20160921141539.GA17898@infradead.org/, but
never followed up with. We recently hit this bug in our testing where
fencing io errors, which were previously erroring out with EIO, were
being returned as success operations after this commit.
The fix proposed on the list earlier was a little short -- it would have
still called generic_write_sync() in case `ret` already contained an
error. This fix ensures generic_write_sync() is only called when there's
no pending error in the write. Additionally, transferred is replaced
with ret to bring this code in line with other callers.
Fixes: e259221763a4 ("fs: simplify the generic_write_sync prototype") Reported-by: Ravi Nankani <rnankani@amazon.com> Signed-off-by: Maximilian Heyne <mheyne@amazon.de> Reviewed-by: Christoph Hellwig <hch@lst.de> CC: Torsten Mehlan <tomeh@amazon.de> CC: Uwe Dannowski <uwed@amazon.de> CC: Amit Shah <aams@amazon.de> CC: David Woodhouse <dwmw@amazon.co.uk> CC: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently we check the branch tracing only by checking for the
PERF_COUNT_HW_BRANCH_INSTRUCTIONS event of PERF_TYPE_HARDWARE
type. But we can define the same event with the PERF_TYPE_RAW
type.
Changing the intel_pmu_has_bts() code to check on event's final
hw config value, so both HW types are covered.
Adding unlikely to intel_pmu_has_bts() condition calls, because
it was used in the original code in intel_bts_constraints.
Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/20181121101612.16272-2-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fpu->initialized = 1; /* step A */
preempt_disable(); /* step B */
fpu__restore(fpu);
preempt_enable();
in __fpu__restore_sig() is racy in regard to a context switch.
For 32bit frames, __fpu__restore_sig() prepares the FPU state within
fpu->state. To ensure that a context switch (switch_fpu_prepare() in
particular) does not modify fpu->state it uses fpu__drop() which sets
fpu->initialized to 0.
After fpu->initialized is cleared, the CPU's FPU state is not saved
to fpu->state during a context switch. The new state is loaded via
fpu__restore(). It gets loaded into fpu->state from userland and
ensured it is sane. fpu->initialized is then set to 1 in order to avoid
fpu__initialize() doing anything (overwrite the new state) which is part
of fpu__restore().
A context switch between step A and B above would save CPU's current FPU
registers to fpu->state and overwrite the newly prepared state. This
looks like a tiny race window but the Kernel Test Robot reported this
back in 2016 while we had lazy FPU support. Borislav Petkov made the
link between that report and another patch that has been posted. Since
the removal of the lazy FPU support, this race goes unnoticed because
the warning has been removed.
Disable bottom halves around the restore sequence to avoid the race. BH
need to be disabled because BH is allowed to run (even with preemption
disabled) and might invoke kernel_fpu_begin() by doing IPsec.
[ bp: massage commit message a bit. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: stable@vger.kernel.org Cc: x86-ml <x86@kernel.org> Link: http://lkml.kernel.org/r/20181120102635.ddv3fvavxajjlfqk@linutronix.de Link: https://lkml.kernel.org/r/20160226074940.GA28911@pd.tnic Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, the code sets up the thresholding interrupt vector and only
then goes about initializing the thresholding banks. Which is wrong,
because an early thresholding interrupt would cause a NULL pointer
dereference when accessing those banks and prevent the machine from
booting.
Therefore, set the thresholding interrupt vector only *after* having
initialized the banks successfully.
Fixes: 18807ddb7f88 ("x86/mce/AMD: Reset Threshold Limit after logging error") Reported-by: Rafał Miłecki <rafal@milecki.pl> Reported-by: John Clemens <clemej@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Rafał Miłecki <rafal@milecki.pl> Tested-by: John Clemens <john@deater.net> Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com> Cc: linux-edac@vger.kernel.org Cc: stable@vger.kernel.org Cc: Tony Luck <tony.luck@intel.com> Cc: x86@kernel.org Cc: Yazen Ghannam <Yazen.Ghannam@amd.com> Link: https://lkml.kernel.org/r/20181127101700.2964-1-zajec5@gmail.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=201291 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes the wrong polarity setting for the PCIe host driver's
pre-reset pin for rk3399-puma-haikou. Without this patch link training
will most likely fail.
The function relocate_block_group calls btrfs_end_transaction to release
trans when update_backref_cache returns 1, and then continues the loop
body. If btrfs_block_rsv_refill fails this time, it will jump out the
loop and the freed trans will be accessed. This may result in a
use-after-free bug. The patch assigns NULL to trans after trans is
released so that it will not be accessed.
Fixes: 0647bf564f1 ("Btrfs: improve forever loop when doing balance relocation") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Pan Bian <bianpan2016@163.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We were using the path name received from user space without checking that
it is null terminated. While btrfs-progs is well behaved and does proper
validation and null termination, someone could call the ioctl and pass
a non-null terminated patch, leading to buffer overrun problems in the
kernel. The ioctl is protected by CAP_SYS_ADMIN.
So just set the last byte of the path to a null character, similar to what
we do in other ioctls (add/remove/resize device, snapshot creation, etc).
CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Layout of coprocessor registers in the elf_xtregs_t and
xtregs_coprocessor_t may be different due to alignment. Thus it is not
always possible to copy data between the xtregs_coprocessor_t structure
and the elf_xtregs_t and get correct values for all registers.
Use a table of offsets and sizes of individual coprocessor register
groups to do coprocessor context copying in the ptrace_getxregs and
ptrace_setxregs.
This fixes incorrect coprocessor register values reading from the user
process by the native gdb on an xtensa core with multiple coprocessors
and registers with high alignment requirements.
Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Coprocessor context offsets are used by the assembly code that moves
coprocessor context between the individual fields of the
thread_info::xtregs_cp structure and coprocessor registers.
This fixes coprocessor context clobbering on flushing and reloading
during normal user code execution and user process debugging in the
presence of more than one coprocessor in the core configuration.
Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
coprocessor_flush_all may be called from a context of a thread that is
different from the thread being flushed. In that case contents of the
cpenable special register may not match ti->cpenable of the target
thread, resulting in unhandled coprocessor exception in the kernel
context.
Set cpenable special register to the ti->cpenable of the target register
for the duration of the flush and restore it afterwards.
This fixes the following crash caused by coprocessor register inspection
in native gdb:
The reason is that the testcase writes hyperv synic HV_X64_MSR_SINT6 msr
and triggers scan ioapic logic to load synic vectors into EOI exit bitmap.
However, irqchip is not initialized by this simple testcase, ioapic/apic
objects should not be accessed.
This can be triggered by the following program:
kvm_pv_clock_pairing() allocates local var
"struct kvm_clock_pairing clock_pairing" on stack and initializes
all it's fields besides padding (clock_pairing.pad[]).
Because clock_pairing var is written completely (including padding)
to guest memory, failure to init struct padding results in kernel
info-leak.
Fix the issue by making sure to also init the padding with zeroes.
Fixes: 55dd00a73a51 ("KVM: x86: add KVM_HC_CLOCK_PAIRING hypercall") Reported-by: syzbot+a8ef68d71211ba264f56@syzkaller.appspotmail.com Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Previously, we only called indirect_branch_prediction_barrier on the
logical CPU that freed a vmcb. This function should be called on all
logical CPUs that last loaded the vmcb in question.
Fixes: 15d45071523d ("KVM/x86: Add IBPB support") Reported-by: Neel Natu <neelnatu@google.com> Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a guest page table is updated via an emulated write,
kvm_mmu_pte_write() is called to update the shadow PTE using the just
written guest PTE value. But if two emulated guest PTE writes happened
concurrently, it is possible that the guest PTE and the shadow PTE end
up being out of sync. Emulated writes do not mark the shadow page as
unsync-ed, so this inconsistency will not be resolved even by a guest TLB
flush (unless the page was marked as unsync-ed at some other point).
This is fixed by re-reading the current value of the guest PTE after the
MMU lock has been acquired instead of just using the value that was
written prior to calling kvm_mmu_pte_write().
Signed-off-by: Junaid Shahid <junaids@google.com> Reviewed-by: Wanpeng Li <wanpengli@tencent.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If 'prctl' mode of user space protection from spectre v2 is selected
on the kernel command-line, STIBP and IBPB are applied on tasks which
restrict their indirect branch speculation via prctl.
SECCOMP enables the SSBD mitigation for sandboxed tasks already, so it
makes sense to prevent spectre v2 user space to user space attacks as
well.
The Intel mitigation guide documents how STIPB works:
Setting bit 1 (STIBP) of the IA32_SPEC_CTRL MSR on a logical processor
prevents the predicted targets of indirect branches on any logical
processor of that core from being controlled by software that executes
(or executed previously) on another logical processor of the same core.
Ergo setting STIBP protects the task itself from being attacked from a task
running on a different hyper-thread and protects the tasks running on
different hyper-threads from being attacked.
While the document suggests that the branch predictors are shielded between
the logical processors, the observed performance regressions suggest that
STIBP simply disables the branch predictor more or less completely. Of
course the document wording is vague, but the fact that there is also no
requirement for issuing IBPB when STIBP is used points clearly in that
direction. The kernel still issues IBPB even when STIBP is used until Intel
clarifies the whole mechanism.
IBPB is issued when the task switches out, so malicious sandbox code cannot
mistrain the branch predictor for the next user space task on the same
logical processor.
Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185006.051663132@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the PR_SPEC_INDIRECT_BRANCH option for the PR_GET_SPECULATION_CTRL and
PR_SET_SPECULATION_CTRL prctls to allow fine grained per task control of
indirect branch speculation via STIBP and IBPB.
Invocations:
Check indirect branch speculation status with
- prctl(PR_GET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, 0, 0, 0);
The upcoming fine grained per task STIBP control needs to be updated on CPU
hotplug as well.
Split out the code which controls the strict mode so the prctl control code
can be added later. Mark the SMP function call argument __unused while at it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185005.759457117@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The seccomp speculation control operates on all tasks of a process, but
only the current task of a process can update the MSR immediately. For the
other threads the update is deferred to the next context switch.
This creates the following situation with Process A and B:
Process A task 2 and Process B task 1 are pinned on CPU1. Process A task 2
does not have the speculation control TIF bit set. Process B task 1 has the
speculation control TIF bit set.
CPU0 CPU1
MSR bit is set
ProcB.T1 schedules out
ProcA.T2 schedules in
MSR bit is cleared
ProcA.T1
seccomp_update()
set TIF bit on ProcA.T2
ProcB.T1 schedules in
MSR is not updated <-- FAIL
This happens because the context switch code tries to avoid the MSR update
if the speculation control TIF bits of the incoming and the outgoing task
are the same. In the worst case ProcB.T1 and ProcA.T2 are the only tasks
scheduling back and forth on CPU1, which keeps the MSR stale forever.
In theory this could be remedied by IPIs, but chasing the remote task which
could be migrated is complex and full of races.
The straight forward solution is to avoid the asychronous update of the TIF
bit and defer it to the next context switch. The speculation control state
is stored in task_struct::atomic_flags by the prctl and seccomp updates
already.
Add a new TIF_SPEC_FORCE_UPDATE bit and set this after updating the
atomic_flags. Check the bit on context switch and force a synchronous
update of the speculation control if set. Use the same mechanism for
updating the current task.
Reported-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1811272247140.1875@nanos.tec.linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The update of the TIF_SSBD flag and the conditional speculation control MSR
update is done in the ssb_prctl_set() function directly. The upcoming prctl
support for controlling indirect branch speculation via STIBP needs the
same mechanism.
Split the code out and make it reusable. Reword the comment about updates
for other tasks.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185005.652305076@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The IBPB speculation barrier is issued from switch_mm() when the kernel
switches to a user space task with a different mm than the user space task
which ran last on the same CPU.
An additional optimization is to avoid IBPB when the incoming task can be
ptraced by the outgoing task. This optimization only works when switching
directly between two user space tasks. When switching from a kernel task to
a user space task the optimization fails because the previous task cannot
be accessed anymore. So for quite some scenarios the optimization is just
adding overhead.
The upcoming conditional IBPB support will issue IBPB only for user space
tasks which have the TIF_SPEC_IB bit set. This requires to handle the
following cases:
1) Switch from a user space task (potential attacker) which has
TIF_SPEC_IB set to a user space task (potential victim) which has
TIF_SPEC_IB not set.
2) Switch from a user space task (potential attacker) which has
TIF_SPEC_IB not set to a user space task (potential victim) which has
TIF_SPEC_IB set.
This needs to be optimized for the case where the IBPB can be avoided when
only kernel threads ran in between user space tasks which belong to the
same process.
The current check whether two tasks belong to the same context is using the
tasks context id. While correct, it's simpler to use the mm pointer because
it allows to mangle the TIF_SPEC_IB bit into it. The context id based
mechanism requires extra storage, which creates worse code.
When a task is scheduled out its TIF_SPEC_IB bit is mangled as bit 0 into
the per CPU storage which is used to track the last user space mm which was
running on a CPU. This bit can be used together with the TIF_SPEC_IB bit of
the incoming task to make the decision whether IBPB needs to be issued or
not to cover the two cases above.
As conditional IBPB is going to be the default, remove the dubious ptrace
check for the IBPB always case and simply issue IBPB always when the
process changes.
Move the storage to a different place in the struct as the original one
created a hole.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185005.466447057@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The TIF_SPEC_IB bit does not need to be evaluated in the decision to invoke
__switch_to_xtra() when:
- CONFIG_SMP is disabled
- The conditional STIPB mode is disabled
The TIF_SPEC_IB bit still controls IBPB in both cases so the TIF work mask
checks might invoke __switch_to_xtra() for nothing if TIF_SPEC_IB is the
only set bit in the work masks.
Optimize it out by masking the bit at compile time for CONFIG_SMP=n and at
run time when the static key controlling the conditional STIBP mode is
disabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185005.374062201@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move the conditional invocation of __switch_to_xtra() into an inline
function so the logic can be shared between 32 and 64 bit.
Remove the handthrough of the TSS pointer and retrieve the pointer directly
in the bitmap handling function. Use this_cpu_ptr() instead of the
per_cpu() indirection.
This is a preparatory change so integration of conditional indirect branch
speculation optimization happens only in one place.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185005.280855518@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To avoid the overhead of STIBP always on, it's necessary to allow per task
control of STIBP.
Add a new task flag TIF_SPEC_IB and evaluate it during context switch if
SMT is active and flag evaluation is enabled by the speculation control
code. Add the conditional evaluation to x86_virt_spec_ctrl() as well so the
guest/host switch works properly.
This has no effect because TIF_SPEC_IB cannot be set yet and the static key
which controls evaluation is off. Preparatory patch for adding the control
code.
[ tglx: Simplify the context switch logic and make the TIF evaluation
depend on SMP=y and on the static key controlling the conditional
update. Rename it to TIF_SPEC_IB because it controls both STIBP and
IBPB ]
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185005.176917199@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add command line control for user space indirect branch speculation
mitigations. The new option is: spectre_v2_user=
The initial options are:
- on: Unconditionally enabled
- off: Unconditionally disabled
-auto: Kernel selects mitigation (default off for now)
When the spectre_v2= command line argument is either 'on' or 'off' this
implies that the application to application control follows that state even
if a contradicting spectre_v2_user= argument is supplied.
Originally-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185005.082720373@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the now exposed real SMT state, not the SMT sysfs control knob
state. This reflects the state of the system when the mitigation status is
queried.
This does not change the warning in the VMX launch code. There the
dependency on the control knob makes sense because siblings could be
brought online anytime after launching the VM.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185004.613357354@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch_smt_update() is only called when the sysfs SMT control knob is
changed. This means that when SMT is enabled in the sysfs control knob the
system is considered to have SMT active even if all siblings are offline.
To allow finegrained control of the speculation mitigations, the actual SMT
state is more interesting than the fact that siblings could be enabled.
Rework the code, so arch_smt_update() is invoked from each individual CPU
hotplug function, and simplify the update function while at it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185004.521974984@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_SCHED_SMT is enabled by all distros, so there is not a real point to
have it configurable. The runtime overhead in the core scheduler code is
minimal because the actual SMT scheduling parts are conditional on a static
key.
This allows to expose the scheduler's SMT state static key to the
speculation control code. Alternatively the scheduler's static key could be
made always available when CONFIG_SMP is enabled, but that's just adding an
unused static key to every other architecture for nothing.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185004.337452245@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the 'sched_smt_present' static key is enabled when at CPU bringup
SMT topology is observed, but it is never disabled. However there is demand
to also disable the key when the topology changes such that there is no SMT
present anymore.
Implement this by making the key count the number of cores that have SMT
enabled.
In particular, the SMT topology bits are set before interrrupts are enabled
and similarly, are cleared after interrupts are disabled for the last time
and the CPU dies.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185004.246110444@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The logic to detect whether there's a change in the previous and next
task's flag relevant to update speculation control MSRs is spread out
across multiple functions.
Consolidate all checks needed for updating speculation control MSRs into
the new __speculation_ctrl_update() helper function.
This makes it easy to pick the right speculation control MSR and the bits
in MSR_IA32_SPEC_CTRL that need updating based on TIF flags changes.
Originally-by: Thomas Lendacky <Thomas.Lendacky@amd.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185004.151077005@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During context switch, the SSBD bit in SPEC_CTRL MSR is updated according
to changes of the TIF_SSBD flag in the current and next running task.
Currently, only the bit controlling speculative store bypass disable in
SPEC_CTRL MSR is updated and the related update functions all have
"speculative_store" or "ssb" in their names.
For enhanced mitigation control other bits in SPEC_CTRL MSR need to be
updated as well, which makes the SSB names inadequate.
Rename the "speculative_store*" functions to a more generic name. No
functional change.
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185004.058866968@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Spectre V2 printout in cpu_show_common() handles conditionals for the
various mitigation methods directly in the sprintf() argument list. That's
hard to read and will become unreadable if more complex decisions need to
be made for a particular method.
Move the conditionals for STIBP and IBPB string selection into helper
functions, so they can be extended later on.
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185003.874479208@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that CONFIG_RETPOLINE hard depends on compiler support, there is no
reason to keep the minimal retpoline support around which only provided
basic protection in the assembly files.
Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Borislav Petkov <bp@suse.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: <srinivas.eeda@oracle.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/f06f0a89-5587-45db-8ed2-0a9d6638d5c0@default Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, IBPB is only issued in cases when switching into a non-dumpable
process, the rationale being to protect such 'important and security
sensitive' processess (such as GPG) from data leaking into a different
userspace process via spectre v2.
This is however completely insufficient to provide proper userspace-to-userpace
spectrev2 protection, as any process can poison branch buffers before being
scheduled out, and the newly scheduled process immediately becomes spectrev2
victim.
In order to minimize the performance impact (for usecases that do require
spectrev2 protection), issue the barrier only in cases when switching between
processess where the victim can't be ptraced by the potential attacker (as in
such cases, the attacker doesn't have to bother with branch buffers at all).
[ tglx: Split up PTRACE_MODE_NOACCESS_CHK into PTRACE_MODE_SCHED and
PTRACE_MODE_IBPB to be able to do ptrace() context tracking reasonably
fine-grained ]
Fixes: 18bf3c3ea8 ("x86/speculation: Use Indirect Branch Prediction Barrier in context switch") Originally-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "WoodhouseDavid" <dwmw@amazon.co.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: "SchauflerCasey" <casey.schaufler@intel.com> Link: https://lkml.kernel.org/r/nycvar.YFH.7.76.1809251437340.15880@cbobk.fhfr.pm Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
STIBP is a feature provided by certain Intel ucodes / CPUs. This feature
(once enabled) prevents cross-hyperthread control of decisions made by
indirect branch predictors.
Enable this feature if
- the CPU is vulnerable to spectre v2
- the CPU supports SMT and has SMT siblings online
- spectre_v2 mitigation autoselection is enabled (default)
After some previous discussion, this leaves STIBP on all the time, as wrmsr
on crossing kernel boundary is a no-no. This could perhaps later be a bit
more optimized (like disabling it in NOHZ, experiment with disabling it in
idle, etc) if needed.
Note that the synchronization of the mask manipulation via newly added
spec_ctrl_mutex is currently not strictly needed, as the only updater is
already being serialized by cpu_add_remove_lock, but let's make this a
little bit more future-proof.
On AMD, the presence of the MSR_SPEC_CTRL feature does not imply that the
SSBD mitigation support should use the SPEC_CTRL MSR. Other features could
have caused the MSR_SPEC_CTRL feature to be set, while a different SSBD
mitigation option is in place.
Update the SSBD support to check for the actual SSBD features that will
use the SPEC_CTRL MSR.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 6ac2f49edb1e ("x86/bugs: Add AMD's SPEC_CTRL MSR usage") Link: http://lkml.kernel.org/r/20180702213602.29202.33151.stgit@tlendack-t1.amdoffice.net Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If either the X86_FEATURE_AMD_SSBD or X86_FEATURE_VIRT_SSBD features are
present, then there is no need to perform the check for the LS_CFG SSBD
mitigation support.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180702213553.29202.21089.stgit@tlendack-t1.amdoffice.net Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The AMD document outlining the SSBD handling
124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
mentions that if CPUID 8000_0008.EBX[24] is set we should be using
the SPEC_CTRL MSR (0x48) over the VIRT SPEC_CTRL MSR (0xC001_011f)
for speculative store bypass disable.
This in effect means we should clear the X86_FEATURE_VIRT_SSBD
flag so that we would prefer the SPEC_CTRL MSR.
See the document titled:
124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
A copy of this document is available at
https://bugzilla.kernel.org/show_bug.cgi?id=199889
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com> Cc: kvm@vger.kernel.org Cc: KarimAllah Ahmed <karahmed@amazon.de> Cc: andrew.cooper3@citrix.com Cc: Joerg Roedel <joro@8bytes.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20180601145921.9500-3-konrad.wilk@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The AMD document outlining the SSBD handling
124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
mentions that the CPUID 8000_0008.EBX[26] will mean that the
speculative store bypass disable is no longer needed.
A copy of this document is available at:
https://bugzilla.kernel.org/show_bug.cgi?id=199889
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com> Cc: kvm@vger.kernel.org Cc: andrew.cooper3@citrix.com Cc: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Link: https://lkml.kernel.org/r/20180601145921.9500-2-konrad.wilk@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The bug is not easily reproducable, as it may occur very infrequently
(we had machines with 20minutes heavy downloading before it occurred)
However, on a virual machine (VMWare on Windows 10 host) it occurred
pretty frequently (1-2 seconds after a speedtest was started)
dev->tx_skb mab be freed via dev_kfree_skb_irq on a callback
before it is set.
This causes the following problems:
- double free of the skb or potential memory leak
- in dmesg: 'recvmsg bug' and 'recvmsg bug 2' and eventually
general protection fault
The proposed patch eliminates a potential racing condition.
Before, usb_submit_urb was called and _after_ that, the skb was attached
(dev->tx_skb). So, on a callback it was possible, however unlikely that the
skb was freed before it was set. That way (because dev->tx_skb was not set
to NULL after it was freed), it could happen that a skb from a earlier
transmission was freed a second time (and the skb we should have freed did
not get freed at all)
Now we free the skb directly in ipheth_tx(). It is not passed to the
callback anymore, eliminating the posibility of a double free of the same
skb. Depending on the retval of usb_submit_urb() we use dev_kfree_skb_any()
respectively dev_consume_skb_any() to free the skb.
Signed-off-by: Oliver Zweigle <Oliver.Zweigle@faro.com> Signed-off-by: Bernd Eckstein <3ernd.Eckstein@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The response for a SNMP request can consist of multiple parts, which
the cmd callback stages into a kernel buffer until all parts have been
received. If the callback detects that the staging buffer provides
insufficient space, it bails out with error.
This processing is buggy for the first part of the response - while it
initially checks for a length of 'data_len', it later copies an
additional amount of 'offsetof(struct qeth_snmp_cmd, data)' bytes.
Fix the calculation of 'data_len' for the first part of the response.
This also nicely cleans up the memcpy code.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
skb is freed via dev_kfree_skb_any, however, skb->len is read then. This
may result in a use-after-free bug.
Fixes: e6161d64263 ("rapidio/rionet: rework driver initialization and removal") Signed-off-by: Pan Bian <bianpan2016@163.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tpacket_snd sends packets with user pages linked into skb frags. It
notifies that pages can be reused when the skb is released by setting
skb->destructor to tpacket_destruct_skb.
This can cause data corruption if the skb is orphaned (e.g., on
transmit through veth) or cloned (e.g., on mirror to another psock).
Create a kernel-private copy of data in these cases, same as tun/tap
zerocopy transmission. Reuse that infrastructure: mark the skb as
SKBTX_ZEROCOPY_FRAG, which will trigger copy in skb_orphan_frags(_rx).
Unlike other zerocopy packets, do not set shinfo destructor_arg to
struct ubuf_info. tpacket_destruct_skb already uses that ptr to notify
when the original skb is released and a timestamp is recorded. Do not
change this timestamp behavior. The ubuf_info->callback is not needed
anyway, as no zerocopy notification is expected.
Mark destructor_arg as not-a-uarg by setting the lower bit to 1. The
resulting value is not a valid ubuf_info pointer, nor a valid
tpacket_snd frame address. Add skb_zcopy_.._nouarg helpers for this.
The fix relies on features introduced in commit 52267790ef52 ("sock:
add MSG_ZEROCOPY"), so can be backported as is only to 4.14.
Tested with from `./in_netns.sh ./txring_overwrite` from
http://github.com/wdebruij/kerneltools/tests
Fixes: 69e3c75f4d54 ("net: TX_RING and packet mmap") Reported-by: Anand H. Krishnan <anandhkrishnan@gmail.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reset snd_queue tso_hdrs pointer to NULL in nicvf_free_snd_queue routine
since it is used to check if tso dma descriptor queue has been previously
allocated. The issue can be triggered with the following reproducer:
$ip link set dev enP2p1s0v0 xdpdrv obj xdp_dummy.o
$ip link set dev enP2p1s0v0 xdpdrv off
where xdp_dummy.c is a simple bpf program that forwards the incoming
frames to the network stack (available here:
https://github.com/altoor/xdp_walkthrough_examples/blob/master/sample_1/xdp_dummy.c)
Fixes: 05c773f52b96 ("net: thunderx: Add basic XDP support") Fixes: 4863dea3fab0 ("net: Adding support for Cavium ThunderX network controller") Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We don't support partial csumed packet since its metadata will be lost
or incorrect during XDP processing. So fail the XDP set if guest_csum
feature is negotiated.
Fixes: f600b6905015 ("virtio_net: Add XDP support") Reported-by: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Pavel Popa <pashinho1990@gmail.com> Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We don't disable VIRTIO_NET_F_GUEST_CSUM if XDP was set. This means we
can receive partial csumed packets with metadata kept in the
vnet_hdr. This may have several side effects:
- It could be overridden by header adjustment, thus is might be not
correct after XDP processing.
- There's no way to pass such metadata information through
XDP_REDIRECT to another driver.
- XDP does not support checksum offload right now.
So simply disable guest csum if possible in this the case of XDP.
Fixes: 3f93522ffab2d ("virtio-net: switch off offloads on demand if possible on XDP set") Reported-by: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Pavel Popa <pashinho1990@gmail.com> Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Set xdp_prog pointer to NULL if bpf_prog_add fails since that routine
reports the error code instead of NULL in case of failure and xdp_prog
pointer value is used in the driver to verify if XDP is currently
enabled.
Moreover report the error code to userspace if nicvf_xdp_setup fails
Fixes: 05c773f52b96 ("net: thunderx: Add basic XDP support") Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a packet is trapped and the corresponding SKB marked as
already-forwarded, it retains this marking even after it is forwarded
across veth links into another bridge. There, since it ingresses the
bridge over veth, which doesn't have offload_fwd_mark, it triggers a
warning in nbp_switchdev_frame_mark().
Then nbp_switchdev_allowed_egress() decides not to allow egress from
this bridge through another veth, because the SKB is already marked, and
the mark (of 0) of course matches. Thus the packet is incorrectly
blocked.
Solve by resetting offload_fwd_mark() in skb_scrub_packet(). That
function is called from tunnels and also from veth, and thus catches the
cases where traffic is forwarded between bridges and transformed in a
way that invalidates the marking.
Fixes: 6bc506b4fb06 ("bridge: switchdev: Add forward mark support for stacked devices") Fixes: abf4bb6b63d0 ("skbuff: Add the offload_mr_fwd_mark field") Signed-off-by: Petr Machata <petrm@mellanox.com> Suggested-by: Ido Schimmel <idosch@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From Dietmar May's report on the stable mailing list
(https://www.spinics.net/lists/stable/msg272201.html):
> I've run into some problems which appear due to (a) recent patch(es) on
> the wlcore wifi driver.
>
> 4.4.160 - commit 3fdd34643ffc378b5924941fad40352c04610294
> 4.9.131 - commit afeeecc764436f31d4447575bb9007732333818c
>
> Earlier versions (4.9.130 and 4.4.159 - tested back to 4.4.49) do not
> exhibit this problem. It is still present in 4.9.141.
>
> master as of 4.20.0-rc4 does not exhibit this problem.
>
> Basically, during client association when in AP mode (running hostapd),
> handshake may or may not complete following a noticeable delay. If
> successful, then the driver fails consistently in warn_slowpath_null
> during disassociation. If unsuccessful, the wifi client attempts multiple
> times, sometimes failing repeatedly. I've had clients unable to connect
> for 3-5 minutes during testing, with the syslog filled with dozens of
> backtraces. syslog details are below.
>
> I'm working on an embedded device with a TI 3352 ARM processor and a
> murata wl1271 module in sdio mode. We're running a fully patched ubuntu
> 18.04 ARM build, with a kernel built from kernel.org's stable/linux repo <https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-4.9.y&id=afeeecc764436f31d4447575bb9007732333818c>.
> Relevant parts of the kernel config are included below.
>
> The commit message states:
>
> > /I've only seen this few times with the runtime PM patches enabled so
> > this one is probably not needed before that. This seems to work
> > currently based on the current PM implementation timer. Let's apply
> > this separately though in case others are hitting this issue./
> We're not doing anything explicit with power management. The device is an
> IoT edge gateway with battery backup, normally running on wall power. The
> battery is currently used solely to shut down the system cleanly to avoid
> filesystem corruption.
>
> The device tree is configured to keep power in suspend; but the device
> should never suspend, so in our case, there is no need to call
> wl1271_ps_elp_wakeup() or wl1271_ps_elp_sleep(), as occurs in the patch.
Kanda Motohiro reported that expanding a tiny xattr into a large xattr
fails on XFS because we remove the tiny xattr from a shortform fork and
then try to re-add it after converting the fork to extents format having
not removed the ATTR_REPLACE flag. This fails because the attr is no
longer present, causing a fs shutdown.
This is derived from the patch in his bug report, but we really
shouldn't ignore a nonzero retval from the remove call.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199119 Reported-by: kanda.motohiro@gmail.com Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
After fuzzing, cp_pack_start_sum could be corrupted, so current log's
summary info should be wrong due to loading incorrect summary block.
Then, if segment's type in current log is exceeded NR_CURSEG_TYPE, it
can lead accessing invalid dirty_i->dirty_segmap bitmap finally.
Add sanity check for cp_pack_start_sum to fix this issue.
- Location
https://elixir.bootlin.com/linux/v4.18-rc3/source/fs/f2fs/segment.c#L775
if (test_and_clear_bit(segno, dirty_i->dirty_segmap[t]))
dirty_i->nr_dirty[t]--;
Here dirty_i->dirty_segmap[t] can be NULL which leads to crash in test_and_clear_bit()
Reported-by Wen Xu <wen.xu@gatech.edu> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
[bwh: Backported to 4.14: The function is called sanity_check_ckpt()] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
If inode.i_extra_isize was fuzzed to an abnormal value, when
calculating inline data size, the result will overflow, result
in accessing invalid memory area when operating inline data.
Let's do sanity check with i_extra_isize during inode loading
for fixing.
int main(int argc, char *argv[]) {
activity(argv[1]);
return 0;
}
- Kernel message
Umount the image will leave the following message
[ 2910.995489] F2FS-fs (loop0): Mounted with checkpoint version = 2
[ 2918.416465] ==================================================================
[ 2918.416807] BUG: KASAN: slab-out-of-bounds in f2fs_iget+0xcb9/0x1a80
[ 2918.417009] Read of size 4 at addr ffff88018efc2068 by task a.out/1229
- Location
https://elixir.bootlin.com/linux/v4.18-rc3/source/fs/f2fs/inline.c#L78
memset(addr + from, 0, MAX_INLINE_DATA(inode) - from);
Here the length can be negative.
Reported-by Wen Xu <wen.xu@gatech.edu> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
[bwh: Backported to 4.14: adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
Reported-by Wen Xu <wen.xu@gatech.edu> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
[bwh: Backported to 4.14:
- Error label is different in validate_checkpoint() due to the earlier
backport of "f2fs: fix invalid memory access"
- Adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
If FI_EXTRA_ATTR is set in inode by fuzzing, inode.i_addr[0] will be
parsed as inode.i_extra_isize, then in __recover_inline_status, inline
data address will beyond boundary of page, result in accessing invalid
memory.
So in this condition, during reading inode page, let's do sanity check
with EXTRA_ATTR feature of fs and extra_attr bit of inode, if they're
inconsistent, deny to load this inode.
- Overview
Out-of-bound access in f2fs_iget() when mounting a corrupted f2fs image
- Reproduce
The following message will be got in KASAN build of 4.18 upstream kernel.
[ 819.392227] ==================================================================
[ 819.393901] BUG: KASAN: slab-out-of-bounds in f2fs_iget+0x736/0x1530
[ 819.395329] Read of size 4 at addr ffff8801f099c968 by task mount/1292
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