In watch_queue_set_filter(), there are a couple of places where we check
that the filter type value does not exceed what the type_filter bitmap
can hold. One place calculates the number of bits by:
if (tf[i].type >= sizeof(wfilter->type_filter) * 8)
which is fine, but the second does:
if (tf[i].type >= sizeof(wfilter->type_filter) * BITS_PER_LONG)
which is not. This can lead to a couple of out-of-bounds writes due to
a too-large type:
(1) __set_bit() on wfilter->type_filter
(2) Writing more elements in wfilter->filters[] than we allocated.
Fix this by just using the proper WATCH_TYPE__NR instead, which is the
number of types we actually know about.
The bug may cause an oops looking something like:
BUG: KASAN: slab-out-of-bounds in watch_queue_set_filter+0x659/0x740
Write of size 4 at addr ffff88800d2c66bc by task watch_queue_oob/611
...
Call Trace:
<TASK>
dump_stack_lvl+0x45/0x59
print_address_description.constprop.0+0x1f/0x150
...
kasan_report.cold+0x7f/0x11b
...
watch_queue_set_filter+0x659/0x740
...
__x64_sys_ioctl+0x127/0x190
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Allocated by task 611:
kasan_save_stack+0x1e/0x40
__kasan_kmalloc+0x81/0xa0
watch_queue_set_filter+0x23a/0x740
__x64_sys_ioctl+0x127/0x190
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
The buggy address belongs to the object at ffff88800d2c66a0
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 28 bytes inside of
32-byte region [ffff88800d2c66a0, ffff88800d2c66c0)
When building for Thumb2, the vectors make use of a local label. Sadly,
the Spectre BHB code also uses a local label with the same number which
results in the Thumb2 reference pointing at the wrong place. Fix this
by changing the number used for the Spectre BHB local label.
The in-kernel ext4 resize code doesn't support filesystem with the
sparse_super2 feature. It fails with errors like this and doesn't finish
the resize:
EXT4-fs (loop0): resizing filesystem from 16640 to 7864320 blocks
EXT4-fs warning (device loop0): verify_reserved_gdb:760: reserved GDT 2 missing grp 1 (32770)
EXT4-fs warning (device loop0): ext4_resize_fs:2111: error (-22) occurred during file system resize
EXT4-fs (loop0): resized filesystem to 2097152
The userspace resize2fs tool has a check for this case: it checks if the
filesystem has sparse_super2 set and if the kernel provides
/sys/fs/ext4/features/sparse_super2. However, the former check requires
manually reading and parsing the filesystem superblock.
Detect this case in ext4_resize_begin and error out early with a clear
error message.
Since kprobe_int3_handler() is called in do_int3(), probing do_int3()
can cause a breakpoint recursion and crash the kernel. Therefore,
do_int3() should be marked as NOKPROBE_SYMBOL.
The x86 boot documentation describes the setup_indirect structures and
how they are used. Only one of the two functions in ioremap.c that needed
to be modified to be aware of the introduction of setup_indirect
functionality was updated. Adds comparable support to the other function
where it was missing.
As documented, the setup_indirect structure is nested inside
the setup_data structures in the setup_data list. The code currently
accesses the fields inside the setup_indirect structure but only
the sizeof(struct setup_data) is being memremapped. No crash
occurred but this is just due to how the area is remapped under the
covers.
Properly memremap both the setup_data and setup_indirect structures
in these cases before accessing them.
watch_queue_clear() has a comment stating that setting ->defunct to true
preventing new additions as well as preventing notifications. Whilst
the latter is true, the first bit is superfluous since at the time this
function is called, the pipe cannot be accessed to add new event
sources.
There's nothing to synchronise post_one_notification() versus
pipe_read(). Whilst posting is done under pipe->rd_wait.lock, the
reader only takes pipe->mutex which cannot bar notification posting as
that may need to be made from contexts that cannot sleep.
Fix this by setting pipe->head with a barrier in post_one_notification()
and reading pipe->head with a barrier in pipe_read().
If that's not sufficient, the rd_wait.lock will need to be taken,
possibly in a ->confirm() op so that it only applies to notifications.
The lock would, however, have to be dropped before copy_page_to_iter()
is invoked.
Currently, watch_queue_set_size() sets the number of notes available in
wqueue->nr_notes according to the number of notes allocated, but sets
the size of the bitmap to the unrounded number of notes originally asked
for.
Fix this by setting the bitmap size to the number of notes we're
actually going to make available (ie. the number allocated).
The pipe ring size must always be a power of 2 as the head and tail
pointers are masked off by AND'ing with the size of the ring - 1.
watch_queue_set_size(), however, lets you specify any number of notes
between 1 and 511. This number is passed through to pipe_resize_ring()
without checking/forcing its alignment.
Fix this by rounding the number of slots required up to the nearest
power of two. The request is meant to guarantee that at least that many
notifications can be generated before the queue is full, so rounding
down isn't an option, but, alternatively, it may be better to give an
error if we aren't allowed to allocate that much ring space.
When a pipe ring descriptor points to a notification message, the
refcount on the backing page is incremented by the generic get function,
but the release function, which marks the bitmap, doesn't drop the page
ref.
Fix this by calling generic_pipe_buf_release() at the end of
watch_queue_pipe_buf_release().
In free_pipe_info(), free the watchqueue state after clearing the pipe
ring as each pipe ring descriptor has a release function, and in the
case of a notification message, this is watch_queue_pipe_buf_release()
which tries to mark the allocation bitmap that was previously released.
Fix this by moving the put of the pipe's ref on the watch queue to after
the ring has been cleared. We still need to call watch_queue_clear()
before doing that to make sure that the pipe is disconnected from any
notification sources first.
The feature negotiation was designed in a way that
makes it possible for devices to know which config
fields will be accessed by drivers.
This is broken since commit 404123c2db79 ("virtio: allow drivers to
validate features") with fallout in at least block and net. We have a
partial work-around in commit 2f9a174f918e ("virtio: write back
F_VERSION_1 before validate") which at least lets devices find out which
format should config space have, but this is a partial fix: guests
should not access config space without acknowledging features since
otherwise we'll never be able to change the config space format.
To fix, split finalize_features from virtio_finalize_features and
call finalize_features with all feature bits before validation,
and then - if validation changed any bits - once again after.
Since virtio_finalize_features no longer writes out features
rename it to virtio_features_ok - since that is what it does:
checks that features are ok with the device.
As a side effect, this also reduces the amount of hypervisor accesses -
we now only acknowledge features once unless we are clearing any
features when validating (which is uncommon).
IRC I think that this was more or less always the intent in the spec but
unfortunately the way the spec is worded does not say this explicitly, I
plan to address this at the spec level, too.
Acked-by: Jason Wang <jasowang@redhat.com> Cc: stable@vger.kernel.org Fixes: 404123c2db79 ("virtio: allow drivers to validate features") Fixes: 2f9a174f918e ("virtio: write back F_VERSION_1 before validate") Cc: "Halil Pasic" <pasic@linux.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
virtio_finalize_features is only used internally within virtio.
No reason to export it.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Legacy and old PCI I/O based cards do not support 32-bit I/O addressing.
Since commit 64f160e19e92 ("PCI: aardvark: Configure PCIe resources from
'ranges' DT property") kernel can set different PCIe address on CPU and
different on the bus for the one A37xx address mapping without any firmware
support in case the bus address does not conflict with other A37xx mapping.
So remap I/O space to the bus address 0x0 to enable support for old legacy
I/O port based cards which have hardcoded I/O ports in low address space.
Note that DDR on A37xx is mapped to bus address 0x0. And mapping of I/O
space can be set to address 0x0 too because MEM space and I/O space are
separate and so do not conflict.
Remapping IO space on Turris Mox to different address is not possible to
due bootloader bug.
RISC-V can do PC-relative jumps with a 32bit range using the following
two instructions:
auipc t0, imm20 ; t0 = PC + imm20 * 2^12
jalr ra, t0, imm12 ; ra = PC + 4, PC = t0 + imm12
Crucially both the 20bit immediate imm20 and the 12bit immediate imm12
are treated as two's-complement signed values. For this reason the
immediates are usually calculated like this:
..where offset is the signed offset from the auipc instruction. When
the 11th bit of offset is 0 the addition of 0x800 doesn't change the top
20 bits and imm12 considered positive. When the 11th bit is 1 the carry
of the addition by 0x800 means imm20 is one higher, but since imm12 is
then considered negative the two's complement representation means it
all cancels out nicely.
However, this addition by 0x800 (2^11) means an offset greater than or
equal to 2^31 - 2^11 would overflow so imm20 is considered negative and
result in a backwards jump. Similarly the lower range of offset is also
moved down by 2^11 and hence the true 32bit range is
Currently meson_mmc_post_req() is called in meson_mmc_request() right
after meson_mmc_start_cmd(). This could lead to DMA unmapping before the request
is actually finished.
To fix, don't call meson_mmc_post_req() until meson_mmc_request_done().
Signed-off-by: Rong Chen <rong.chen@amlogic.com> Reviewed-by: Kevin Hilman <khilman@baylibre.com> Fixes: 79ed05e329c3 ("mmc: meson-gx: add support for descriptor chain mode") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220216124239.4007667-1-rong.chen@amlogic.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is an oddity in the way the RSR register flags propagate to the
ISR register (and the actual interrupt output) on this hardware: it
appears that RSR register bits only result in ISR being asserted if the
interrupt was actually enabled at the time, so enabling interrupts with
RSR bits already set doesn't trigger an interrupt to be raised. There
was already a partial fix for this race in the macb_poll function where
it checked for RSR bits being set and re-triggered NAPI receive.
However, there was a still a race window between checking RSR and
actually enabling interrupts, where a lost wakeup could happen. It's
necessary to check again after enabling interrupts to see if RSR was set
just prior to the interrupt being enabled, and re-trigger receive in that
case.
This issue was noticed in a point-to-point UDP request-response protocol
which periodically saw timeouts or abnormally high response times due to
received packets not being processed in a timely fashion. In many
applications, more packets arriving, including TCP retransmissions, would
cause the original packet to be processed, thus masking the issue.
Fixes: 02f7a34f34e3 ("net: macb: Re-enable RX interrupt only when RX is done") Cc: stable@vger.kernel.org Co-developed-by: Scott McNutt <scott.mcnutt@siriusxm.com> Signed-off-by: Scott McNutt <scott.mcnutt@siriusxm.com> Signed-off-by: Robert Hancock <robert.hancock@calian.com> Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 54659ca026e5 ("staging: rtl8723bs: remove possible deadlock when
disconnect (v2)") split the locking of pxmitpriv->lock vs sleep_q/lock
into 2 locks in attempt to fix a lockdep reported issue with the locking
order of the sta_hash_lock vs pxmitpriv->lock.
But in the end this turned out to not fully solve the sta_hash_lock issue
so commit a7ac783c338b ("staging: rtl8723bs: remove a second possible
deadlock") was added to fix this in another way.
The original fix was kept as it was still seen as a good thing to have,
but now it turns out that it creates a deadlock in access-point mode:
[Feb20 23:47] ======================================================
[ +0.074085] WARNING: possible circular locking dependency detected
[ +0.074077] 5.16.0-1-amd64 #1 Tainted: G C E
[ +0.064710] ------------------------------------------------------
[ +0.074075] ksoftirqd/3/29 is trying to acquire lock:
[ +0.060542] ffffb8b30062ab00 (&pxmitpriv->lock){+.-.}-{2:2}, at: rtw_xmit_classifier+0x8a/0x140 [r8723bs]
[ +0.114921]
but task is already holding lock:
[ +0.069908] ffffb8b3007ab704 (&psta->sleep_q.lock){+.-.}-{2:2}, at: wakeup_sta_to_xmit+0x3b/0x300 [r8723bs]
[ +0.116976]
which lock already depends on the new lock.
[ +0.070950] 1 lock held by ksoftirqd/3/29:
[ +0.049082] #0: ffffb8b3007ab704 (&psta->sleep_q.lock){+.-.}-{2:2}, at: wakeup_sta_to_xmit+0x3b/0x300 [r8723bs]
Analysis shows that in hindsight the splitting of the lock was not
a good idea, so revert this to fix the access-point mode deadlock.
Note this is a straight-forward revert done with git revert, the commented
out "/* spin_lock_bh(&psta_bmc->sleep_q.lock); */" lines were part of the
code before the reverted changes.
In FOPEN_DIRECT_IO mode, fuse_file_write_iter() calls
fuse_direct_write_iter(), which normally calls fuse_direct_io(), which then
imports the write buffer with fuse_get_user_pages(), which uses
iov_iter_get_pages() to grab references to userspace pages instead of
actually copying memory.
On the filesystem device side, these pages can then either be read to
userspace (via fuse_dev_read()), or splice()d over into a pipe using
fuse_dev_splice_read() as pipe buffers with &nosteal_pipe_buf_ops.
This is wrong because after fuse_dev_do_read() unlocks the FUSE request,
the userspace filesystem can mark the request as completed, causing write()
to return. At that point, the userspace filesystem should no longer have
access to the pipe buffer.
Fix by copying pages coming from the user address space to new pipe
buffers.
When CONFIG_GENERIC_CPU_VULNERABILITIES is not set, references
to spectre_v2_update_state() cause a build error, so provide an
empty stub for that function when the Kconfig option is not set.
Fixes this build error:
arm-linux-gnueabi-ld: arch/arm/mm/proc-v7-bugs.o: in function `cpu_v7_bugs_init':
proc-v7-bugs.c:(.text+0x52): undefined reference to `spectre_v2_update_state'
arm-linux-gnueabi-ld: proc-v7-bugs.c:(.text+0x82): undefined reference to `spectre_v2_update_state'
Fixes: b9baf5c8c5c3 ("ARM: Spectre-BHB workaround") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: kernel test robot <lkp@intel.com> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: patches@armlinux.org.uk Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Running the memfd script ./run_hugetlbfs_test.sh will often end in error
as follows:
memfd-hugetlb: CREATE
memfd-hugetlb: BASIC
memfd-hugetlb: SEAL-WRITE
memfd-hugetlb: SEAL-FUTURE-WRITE
memfd-hugetlb: SEAL-SHRINK
fallocate(ALLOC) failed: No space left on device
./run_hugetlbfs_test.sh: line 60: 166855 Aborted (core dumped) ./memfd_test hugetlbfs
opening: ./mnt/memfd
fuse: DONE
If no hugetlb pages have been preallocated, run_hugetlbfs_test.sh will
allocate 'just enough' pages to run the test. In the SEAL-FUTURE-WRITE
test the mfd_fail_write routine maps the file, but does not unmap. As a
result, two hugetlb pages remain reserved for the mapping. When the
fallocate call in the SEAL-SHRINK test attempts allocate all hugetlb
pages, it is short by the two reserved pages.
Fix by making sure to unmap in mfd_fail_write.
Link: https://lkml.kernel.org/r/20220219004340.56478-1-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
valid_lft, prefered_lft and tstamp are always accessed under the lock
"lock" in other places. Reading these without taking the lock may result
in inconsistencies regarding the calculation of the valid and preferred
variables since decisions are taken on these fields for those variables.
The reasoning in the commit was wrong - the code expected to setup the
watch even if 'hotplug-status' didn't exist. In fact, it relied on the
watch being fired the first time - to check if maybe 'hotplug-status' is
already set to 'connected'. Not registering a watch for non-existing
path (which is the case if hotplug script hasn't been executed yet),
made the backend not waiting for the hotplug script to execute. This in
turns, made the netfront think the interface is fully operational, while
in fact it was not (the vif interface on xen-netback side might not be
configured yet).
This was a workaround for 'hotplug-status' erroneously being removed.
But since that is reverted now, the workaround is not necessary either.
More discussion at
https://lore.kernel.org/xen-devel/afedd7cb-a291-e773-8b0d-4db9b291fa98@ipxe.org/T/#u
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Reviewed-by: Paul Durrant <paul@xen.org> Reviewed-by: Michael Brown <mbrown@fensystems.co.uk> Link: https://lore.kernel.org/r/20220222001817.2264967-2-marmarek@invisiblethingslab.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The 'hotplug-status' node should not be removed as long as the vif
device remains configured. Otherwise the xen-netback would wait for
re-running the network script even if it was already called (in case of
the frontent re-connecting). But also, it _should_ be removed when the
vif device is destroyed (for example when unbinding the driver) -
otherwise hotplug script would not configure the device whenever it
re-appear.
Moving removal of the 'hotplug-status' node was a workaround for nothing
calling network script after xen-netback module is reloaded. But when
vif interface is re-created (on xen-netback unbind/bind for example),
the script should be called, regardless of who does that - currently
this case is not handled by the toolstack, and requires manual
script call. Keeping hotplug-status=connected to skip the call is wrong
and leads to not configured interface.
More discussion at
https://lore.kernel.org/xen-devel/afedd7cb-a291-e773-8b0d-4db9b291fa98@ipxe.org/T/#u
We are racing the registering of .to_irq when probing the
i2c driver. This results in random failure of touchscreen
devices.
Following explains the race condition better.
[gpio driver] gpio driver registers gpio chip
[gpio consumer] gpio is acquired
[gpio consumer] gpiod_to_irq() fails with -ENXIO
[gpio driver] gpio driver registers irqchip
gpiod_to_irq works at this point, but -ENXIO is fatal
We could see the following errors in dmesg logs when gc->to_irq is NULL
[2.101857] i2c_hid i2c-FTS3528:00: HID over i2c has not been provided an Int IRQ
[2.101953] i2c_hid: probe of i2c-FTS3528:00 failed with error -22
To avoid this situation, defer probing until to_irq is registered.
Returning -EPROBE_DEFER would be the first step towards avoiding
the failure of devices due to the race in registration of .to_irq.
Final solution to this issue would be to avoid using gc irq members
until they are fully initialized.
This issue has been reported many times in past and people have been
using workarounds like changing the pinctrl_amd to built-in instead
of loading it as a module or by adding a softdep for pinctrl_amd into
the config file.
Almost all fault/warning bits in pmbus status registers remain set even
after fault/warning condition are removed. As per pmbus specification
these faults must be cleared by user.
Modify hwmon behavior to clear fault/warning bit after fetching data if
fault/warning bit was set. This allows to get fresh data in next read.
Add a test that validates that timer value is not overwritten when doing
a copy_map_value call in the kernel. Without the prior fix, this test
triggers a crash.
Some of the bcmgenet platforms don't correctly support WOL, yet
ethtool returns:
"Supports Wake-on: gsf"
which is false.
Ideally if there isn't a wol_irq, or there is something else that
keeps the device from being able to wakeup it should display:
"Supports Wake-on: d"
This patch checks whether the device can wakup, before using the
hard-coded supported flags. This corrects the ethtool reporting, as
well as the WOL configuration because ethtool verifies that the mode
is supported before attempting it.
Fixes: c51de7f3976b ("net: bcmgenet: add Wake-on-LAN support code") Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Tested-by: Peter Robinson <pbrobinson@gmail.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20220310045535.224450-1-jeremy.linton@arm.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The of_find_compatible_node() function returns a node pointer with
refcount incremented, We should use of_node_put() on it when done
Add the missing of_node_put() to release the refcount.
Fixes: 7349a74ea75c ("net: ethernet: gianfar_ethtool: get phc index through drvdata") Signed-off-by: Miaoqian Lin <linmq006@gmail.com> Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com> Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com> Link: https://lore.kernel.org/r/20220310015313.14938-1-linmq006@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
This works around an issue with the hardware where both OE and
DAT are exposed in the same register. If both are updated
simultaneously, the harware makes no guarantees that OE or DAT
will actually change in any given order and may result in a
glitch of a few ns on a GPIO pin when changing direction and value
in a single write.
Setting direction to input now only affects OE bit. Setting
direction to output updates DAT first, then OE.
The cleanup() function takes care of killing processes launched by the
test functions. It relies on variables like ${tcpdump_pids} to get the
relevant PIDs. But tests are run in their own subshell, so updated
*_pids values are invisible to other shells. Therefore cleanup() never
sees any process to kill:
Fix this by running cleanup() in the context of the test subshell.
Now that each test cleans the environment after completion, there's no
need for calling cleanup() again when the next test starts. So let's
drop it from the setup() function. This is okay because cleanup() is
also called when pmtu.sh starts, so even the first test starts in a
clean environment.
Also, use tcpdump's immediate mode. Otherwise it might not have time to
process buffered packets, resulting in missing packets or even empty
pcap files for short tests.
Note: PAUSE_ON_FAIL is still evaluated before cleanup(), so one can
still inspect the test environment upon failure when using -p.
Syzbot reported UAF in port100_send_complete(). The root case is in
missing usb_kill_urb() calls on error handling path of ->probe function.
port100_send_complete() accesses devm allocated memory which will be
freed on probe failure. We should kill this urbs before returning an
error from probe function to prevent reported use-after-free
Fail log:
BUG: KASAN: use-after-free in port100_send_complete+0x16e/0x1a0 drivers/nfc/port100.c:935
Read of size 1 at addr ffff88801bb59540 by task ksoftirqd/2/26
...
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0x8d/0x303 mm/kasan/report.c:255
__kasan_report mm/kasan/report.c:442 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
port100_send_complete+0x16e/0x1a0 drivers/nfc/port100.c:935
__usb_hcd_giveback_urb+0x2b0/0x5c0 drivers/usb/core/hcd.c:1670
There could be multiple multipath entries but changing the port affinity
for each one doesn't make much sense and there should be a default one.
So only track the entry with lowest priority value.
The commit doesn't affect existing users with a single entry.
Fixes: 544fe7c2e654 ("net/mlx5e: Activate HW multipath and handle port affinity based on FIB events") Signed-off-by: Roi Dayan <roid@nvidia.com> Reviewed-by: Maor Dickman <maord@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Fix a refcount use after free warning due to a race on command entry.
Such race occurs when one of the commands releases its last refcount and
frees its index and entry while another process running command flush
flow takes refcount to this command entry. The process which handles
commands flush may see this command as needed to be flushed if the other
process released its refcount but didn't release the index yet. Fix it
by adding the needed spin lock.
When two ax25 devices attempted to establish connection, the requester use ax25_create(),
ax25_bind() and ax25_connect() to initiate connection. The receiver use ax25_rcv() to
accept connection and use ax25_create_cb() in ax25_rcv() to create ax25_cb, but the
ax25_cb->sk is NULL. When the receiver is detaching, a NULL pointer dereference bug
caused by sock_hold(sk) in ax25_kill_by_device() will happen. The corresponding
fail log is shown below:
This patch add condition check in ax25_kill_by_device(). If s->sk is
NULL, it will goto if branch to kill device.
Fixes: 4e0f718daf97 ("ax25: improve the incomplete fix to avoid UAF and NPD bugs") Reported-by: Thomas Osterried <thomas@osterried.de> Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
When receiving a state message, function tipc_link_validate_msg()
is called to validate its header portion. Then, its data portion
is validated before it can be accessed correctly. However, current
data sanity check is done after the message header is accessed to
update some link variables.
This commit fixes this issue by moving the data sanity check to
the beginning of state message handling and right after the header
sanity check.
Fixes: 9aa422ad3266 ("tipc: improve size validations for received domain records") Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> Link: https://lore.kernel.org/r/20220308021200.9245-1-tung.q.nguyen@dektech.com.au Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
This node pointer is returned by of_parse_phandle() with refcount
incremented in this function. Calling of_node_put() to avoid the
refcount leak. As the remove function do.
Fixes: 5cdaaa12866e ("net: emaclite: adding MDIO and phy lib support") Signed-off-by: Miaoqian Lin <linmq006@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20220308024751.2320-1-linmq006@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Change curr_link_speed advertised speed, due to
link_info.link_speed is not equal phy.curr_user_speed_req.
Without this patch it is impossible to set advertised
speed to same as link_speed.
Testing Hints: Try to set advertised speed
to 25G only with 25G default link (use ethtool -s 0x80000000)
Fixes: 48cb27f2fd18 ("ice: Implement handlers for ethtool PHY/link operations") Signed-off-by: Grzegorz Siwik <grzegorz.siwik@intel.com> Signed-off-by: Jedrzej Jagielski <jedrzej.jagielski@intel.com> Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel) Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The loop checking for PF VSI doesn't make any sense. The VSI type
backing the netdev passed to ice_set_link_ksettings will always be
of type ICE_PF_VSI. Remove it.
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com> Tested-by: Tony Brelinski <tonyx.brelinski@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
For get PHY abilities AQ, the specification defines "report modes"
as "with media", "without media" and "active configuration". For
clarity, rename macros to align with the specification.
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com> Tested-by: Tony Brelinski <tonyx.brelinski@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The ice_vc_send_msg_to_vf function has logic to detect "failure"
responses being sent to a VF. If a VF is sent more than
ICE_DFLT_NUM_INVAL_MSGS_ALLOWED then the VF is marked as disabled.
Almost identical logic also existed in the i40e driver.
This logic was added to the ice driver in commit 1071a8358a28 ("ice:
Implement virtchnl commands for AVF support") which itself copied from
the i40e implementation in commit 5c3c48ac6bf5 ("i40e: implement virtual
device interface").
Neither commit provides a proper explanation or justification of the
check. In fact, later commits to i40e changed the logic to allow
bypassing the check in some specific instances.
The "logic" for this seems to be that error responses somehow indicate a
malicious VF. This is not really true. The PF might be sending an error
for any number of reasons such as lack of resources, etc.
Additionally, this causes the PF to log an info message for every failed
VF response which may confuse users, and can spam the kernel log.
This behavior is not documented as part of any requirement for our
products and other operating system drivers such as the FreeBSD
implementation of our drivers do not include this type of check.
In fact, the change from dev_err to dev_info in i40e commit 18b7af57d9c1
("i40e: Lower some message levels") explains that these messages
typically don't actually indicate a real issue. It is quite likely that
a user who hits this in practice will be very confused as the VF will be
disabled without an obvious way to recover.
We already have robust malicious driver detection logic using actual
hardware detection mechanisms that detect and prevent invalid device
usage. Remove the logic since its not a documented requirement and the
behavior is not intuitive.
Fixes: 1071a8358a28 ("ice: Implement virtchnl commands for AVF support") Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The i40e_vc_send_msg_to_vf_ex (and its wrapper i40e_vc_send_msg_to_vf)
function has logic to detect "failure" responses sent to the VF. If a VF
is sent more than I40E_DEFAULT_NUM_INVALID_MSGS_ALLOWED, then the VF is
marked as disabled. In either case, a dev_info message is printed
stating that a VF opcode failed.
This logic originates from the early implementation of VF support in
commit 5c3c48ac6bf5 ("i40e: implement virtual device interface").
That commit did not go far enough. The "logic" for this behavior seems
to be that error responses somehow indicate a malicious VF. This is not
really true. The PF might be sending an error for any number of reasons
such as lacking resources, an unsupported operation, etc. This does not
indicate a malicious VF. We already have a separate robust malicious VF
detection which relies on hardware logic to detect and prevent a variety
of behaviors.
There is no justification for this behavior in the original
implementation. In fact, a later commit 18b7af57d9c1 ("i40e: Lower some
message levels") reduced the opcode failure message from a dev_err to a
dev_info. In addition, recent commit 01cbf50877e6 ("i40e: Fix to not
show opcode msg on unsuccessful VF MAC change") changed the logic to
allow quieting it for expected failures.
That commit prevented this logic from kicking in for specific
circumstances. This change did not go far enough. The behavior is not
documented nor is it part of any requirement for our products. Other
operating systems such as the FreeBSD implementation of our driver do
not include this logic.
It is clear this check does not make sense, and causes problems which
led to ugly workarounds.
Fix this by just removing the entire logic and the need for the
i40e_vc_send_msg_to_vf_ex function.
Fixes: 01cbf50877e6 ("i40e: Fix to not show opcode msg on unsuccessful VF MAC change") Fixes: 5c3c48ac6bf5 ("i40e: implement virtual device interface") Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
[ 0.742963] aspeed-g6-pinctrl 1e6e2000.syscon:pinctrl: invalid function FWQSPID in map table

This is because the quad mode pins are a group of pins, not a function.
After applying this patch we can request the pins and the QSPI data
lines are muxed:
# cat /sys/kernel/debug/pinctrl/1e6e2000.syscon\:pinctrl-aspeed-g6-pinctrl/pinmux-pins |grep 1e620000.spi
pin 196 (AE12): device 1e620000.spi function FWSPID group FWQSPID
pin 197 (AF12): device 1e620000.spi function FWSPID group FWQSPID
pin 240 (Y1): device 1e620000.spi function FWSPID group FWQSPID
pin 241 (Y2): device 1e620000.spi function FWSPID group FWQSPID
pin 242 (Y3): device 1e620000.spi function FWSPID group FWQSPID
pin 243 (Y4): device 1e620000.spi function FWSPID group FWQSPID
Discussing one of the tests in mt753x_phylink_validate() with Landen
Chao confirms that the "||" should be "&&". Fix this.
Fixes: c288575f7810 ("net: dsa: mt7530: Add the support of MT7531 switch") Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Link: https://lore.kernel.org/r/E1nRCF0-00CiXD-7q@rmk-PC.armlinux.org.uk Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Clang static analysis reports this issue
qed_sriov.c:4727:19: warning: Assigned value is
garbage or undefined
ivi->max_tx_rate = tx_rate ? tx_rate : link.speed;
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
link is only sometimes set by the call to qed_iov_get_link()
qed_iov_get_link fails without setting link or returning
status. So change the decl to return status.
Fixes: 73390ac9d82b ("qed*: support ndo_get_vf_config") Signed-off-by: Tom Rix <trix@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
The xfrm{4,6}_beet_gso_segment() functions did not correctly set the
SKB_GSO_IPXIP4 and SKB_GSO_IPXIP6 gso types for the address family
tunneling case. Fix this by setting these gso types.
Currently the value of max_discard_segment will be set to
MAX_DISCARD_SEGMENTS (256) with no basis in hardware if device
set 0 to max_discard_seg in configuration space. It's incorrect
since the device might not be able to handle such large descriptors.
To fix it, let's follow max_segments restrictions in this case.
Fixes: 1f23816b8eb8 ("virtio_blk: add discard and write zeroes support") Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Link: https://lore.kernel.org/r/20220304100058.116-1-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
dsp_pipeline_build() allocates dup pointer by kstrdup(cfg),
but then it updates dup variable by strsep(&dup, "|").
As a result when it calls kfree(dup), the dup variable contains NULL.
Found by Linux Driver Verification project (linuxtesting.org) with SVACE.
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Fixes: 960366cf8dbb ("Add mISDN DSP") Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
As Leon Romanovsky's tips:
The definition of macro PIPELINE_DEBUG is commented more than 10 years ago
and can be seen as a dead code that should be removed.
Suggested-by: Leon Romanovsky <leon@kernel.org> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
The node in question is receiving activate messages in another
thread after changing bearer status to allow message sending/
receiving in current thread:
The driver creates the top row map sysfs attribute in input_configured()
method; unfortunately we do not have a callback that is executed when HID
interface is unbound, thus we are leaking these sysfs attributes, for
example when device is disconnected.
To fix it let's switch to managed version of adding sysfs attributes which
will ensure that they are destroyed when the driver is unbound.
GDSCs have multiple transition delays which are used for the GDSC FSM
states. Older targets/designs required these values to be updated from
gdsc code to certain default values for the FSM state to work as
expected. But on the newer targets/designs the values updated from the
GDSC driver can hamper the FSM state to not work as expected.
On SC7180 we observe black screens because the gdsc is being
enabled/disabled very rapidly and the GDSC FSM state does not work as
expected. This is due to the fact that the GDSC reset value is being
updated from SW.
Thus add support to update the transition delay from the clock
controller gdscs as required.
Fixes: 45dd0e55317cc ("clk: qcom: Add support for GDSCs) Signed-off-by: Taniya Das <tdas@codeaurora.org> Link: https://lore.kernel.org/r/20220223185606.3941-1-tdas@codeaurora.org Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
While the HVS has the same context memory size in the BCM2711 than in
the previous SoCs, the range allocated to the registers doubled and it
now takes 16k + 16k, compared to 8k + 16k before.
The KMS driver will use the whole context RAM though, eventually
resulting in a pointer dereference error when we access the higher half
of the context memory since it hasn't been mapped.
Fixes: 4564363351e2 ("ARM: dts: bcm2711: Enable the display pipeline") Signed-off-by: Maxime Ripard <maxime@cerno.tech> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
When calling gnttab_end_foreign_access_ref() the returned value must
be tested and the reaction to that value should be appropriate.
In case of failure in xennet_get_responses() the reaction should not be
to crash the system, but to disable the network device.
The calls in setup_netfront() can be replaced by calls of
gnttab_end_foreign_access(). While at it avoid double free of ring
pages and grant references via xennet_disconnect_backend() in this case.
This is CVE-2022-23042 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gnttab_end_foreign_access() is used to free a grant reference and
optionally to free the associated page. In case the grant is still in
use by the other side processing is being deferred. This leads to a
problem in case no page to be freed is specified by the caller: the
caller doesn't know that the page is still mapped by the other side
and thus should not be used for other purposes.
The correct way to handle this situation is to take an additional
reference to the granted page in case handling is being deferred and
to drop that reference when the grant reference could be freed
finally.
This requires that there are no users of gnttab_end_foreign_access()
left directly repurposing the granted page after the call, as this
might result in clobbered data or information leaks via the not yet
freed grant reference.
This is part of CVE-2022-23041 / XSA-396.
Reported-by: Simon Gaiser <simon@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of __get_free_pages() and free_pages() use alloc_pages_exact()
and free_pages_exact(). This is in preparation of a change of
gnttab_end_foreign_access() which will prohibit use of high-order
pages.
This is part of CVE-2022-23041 / XSA-396.
Reported-by: Simon Gaiser <simon@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of __get_free_pages() and free_pages() use alloc_pages_exact()
and free_pages_exact(). This is in preparation of a change of
gnttab_end_foreign_access() which will prohibit use of high-order
pages.
By using the local variable "order" instead of ring->intf->ring_order
in the error path of xen_9pfs_front_alloc_dataring() another bug is
fixed, as the error path can be entered before ring->intf->ring_order
is being set.
By using alloc_pages_exact() the size in bytes is specified for the
allocation, which fixes another bug for the case of
order < (PAGE_SHIFT - XEN_PAGE_SHIFT).
This is part of CVE-2022-23041 / XSA-396.
Reported-by: Simon Gaiser <simon@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove gnttab_query_foreign_access(), as it is unused and unsafe to
use.
All previous use cases assumed a grant would not be in use after
gnttab_query_foreign_access() returned 0. This information is useless
in best case, as it only refers to a situation in the past, which could
have changed already.
Using gnttab_query_foreign_access() is unsafe, as it is racy by design.
The use case in the gntalloc driver is not needed at all. While at it
replace the call of gnttab_end_foreign_access_ref() with a call of
gnttab_end_foreign_access(), which is what is really wanted there. In
case the grant wasn't used due to an allocation failure, just free the
grant via gnttab_free_grant_reference().
This is CVE-2022-23039 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It isn't enough to check whether a grant is still being in use by
calling gnttab_query_foreign_access(), as a mapping could be realized
by the other side just after having called that function.
In case the call was done in preparation of revoking a grant it is
better to do so via gnttab_try_end_foreign_access() and check the
success of that operation instead.
This is CVE-2022-23038 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It isn't enough to check whether a grant is still being in use by
calling gnttab_query_foreign_access(), as a mapping could be realized
by the other side just after having called that function.
In case the call was done in preparation of revoking a grant it is
better to do so via gnttab_end_foreign_access_ref() and check the
success of that operation instead.
This is CVE-2022-23037 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It isn't enough to check whether a grant is still being in use by
calling gnttab_query_foreign_access(), as a mapping could be realized
by the other side just after having called that function.
In case the call was done in preparation of revoking a grant it is
better to do so via gnttab_end_foreign_access_ref() and check the
success of that operation instead.
For the ring allocation use alloc_pages_exact() in order to avoid
high order pages in case of a multi-page ring.
If a grant wasn't unmapped by the backend without persistent grants
being used, set the device state to "error".
This is CVE-2022-23036 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a new grant table function gnttab_try_end_foreign_access(), which
will remove and free a grant if it is not in use.
Its main use case is to either free a grant if it is no longer in use,
or to take some other action if it is still in use. This other action
can be an error exit, or (e.g. in the case of blkfront persistent grant
feature) some special handling.
This is CVE-2022-23036, CVE-2022-23038 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Letting xenbus_grant_ring() tear down grants in the error case is
problematic, as the other side could already have used these grants.
Calling gnttab_end_foreign_access_ref() without checking success is
resulting in an unclear situation for any caller of xenbus_grant_ring()
as in the error case the memory pages of the ring page might be
partially mapped. Freeing them would risk unwanted foreign access to
them, while not freeing them would leak memory.
In order to remove the need to undo any gnttab_grant_foreign_access()
calls, use gnttab_alloc_grant_references() to make sure no further
error can occur in the loop granting access to the ring pages.
It should be noted that this way of handling removes leaking of
grant entries in the error case, too.
This is CVE-2022-23040 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ld.lld does not support the NOCROSSREFS directive at the moment, which
breaks the build after commit b9baf5c8c5c3 ("ARM: Spectre-BHB
workaround"):
ld.lld: error: ./arch/arm/kernel/vmlinux.lds:34: AT expected, but got NOCROSSREFS
Support for this directive will eventually be implemented, at which
point a version check can be added. To avoid breaking the build in the
meantime, just define NOCROSSREFS to nothing when using ld.lld, with a
link to the issue for tracking.
In the recent Spectre BHB patches, there was a typo that is only
exposed in certain configurations: mcr p15,0,XX,c7,r5,4 should have
been mcr p15,0,XX,c7,c5,4
Reported-by: kernel test robot <lkp@intel.com> Fixes: b9baf5c8c5c3 ("ARM: Spectre-BHB workaround") Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The mitigations for Spectre-BHB are only applied when an exception is
taken from user-space. The mitigation status is reported via the spectre_v2
sysfs vulnerabilities file.
When unprivileged eBPF is enabled the mitigation in the exception vectors
can be avoided by an eBPF program.
When unprivileged eBPF is enabled, print a warning and report vulnerable
via the sysfs vulnerabilities file.
Future CPUs may implement a clearbhb instruction that is sufficient
to mitigate SpectreBHB. CPUs that implement this instruction, but
not CSV2.3 must be affected by Spectre-BHB.
Add support to use this instruction as the BHB mitigation on CPUs
that support it. The instruction is in the hint space, so it will
be treated by a NOP as older CPUs.
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
[ modified for stable: Use a KVM vector template instead of alternatives,
removed bitmap of mitigations ] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM allows the guest to discover whether the ARCH_WORKAROUND SMCCC are
implemented, and to preserve that state during migration through its
firmware register interface.
Add the necessary boiler plate for SMCCC_ARCH_WORKAROUND_3.
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Speculation attacks against some high-performance processors can
make use of branch history to influence future speculation.
When taking an exception from user-space, a sequence of branches
or a firmware call overwrites or invalidates the branch history.
The sequence of branches is added to the vectors, and should appear
before the first indirect branch. For systems using KPTI the sequence
is added to the kpti trampoline where it has a free register as the exit
from the trampoline is via a 'ret'. For systems not using KPTI, the same
register tricks are used to free up a register in the vectors.
For the firmware call, arch-workaround-3 clobbers 4 registers, so
there is no choice but to save them to the EL1 stack. This only happens
for entry from EL0, so if we take an exception due to the stack access,
it will not become re-entrant.
For KVM, the existing branch-predictor-hardening vectors are used.
When a spectre version of these vectors is in use, the firmware call
is sufficient to mitigate against Spectre-BHB. For the non-spectre
versions, the sequence of branches is added to the indirect vector.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
[ modified for stable, removed bitmap of mitigations, use kvm template
infrastructure ] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CPUs vulnerable to Spectre-BHB either need to make an SMC-CC firmware
call from the vectors, or run a sequence of branches. This gets added
to the hyp vectors. If there is no support for arch-workaround-1 in
firmware, the indirect vector will be used.
kvm_init_vector_slots() only initialises the two indirect slots if
the platform is vulnerable to Spectre-v3a. pKVM's hyp_map_vectors()
only initialises __hyp_bp_vect_base if the platform is vulnerable to
Spectre-v3a.
As there are about to more users of the indirect vectors, ensure
their entries in hyp_spectre_vector_selector[] are always initialised,
and __hyp_bp_vect_base defaults to the regular VA mapping.
The Spectre-v3a check is moved to a helper
kvm_system_needs_idmapped_vectors(), and merged with the code
that creates the hyp mappings.
Speculation attacks against some high-performance processors can
make use of branch history to influence future speculation as part of
a spectre-v2 attack. This is not mitigated by CSV2, meaning CPUs that
previously reported 'Not affected' are now moderately mitigated by CSV2.
Update the value in /sys/devices/system/cpu/vulnerabilities/spectre_v2
to also show the state of the BHB mitigation.
The Spectre-BHB workaround adds a firmware call to the vectors. This
is needed on some CPUs, but not others. To avoid the unaffected CPU in
a big/little pair from making the firmware call, create per cpu vectors.
The per-cpu vectors only apply when returning from EL0.
Systems using KPTI can use the canonical 'full-fat' vectors directly at
EL1, the trampoline exit code will switch to this_cpu_vector on exit to
EL0. Systems not using KPTI should always use this_cpu_vector.
this_cpu_vector will point at a vector in tramp_vecs or
__bp_harden_el1_vectors, depending on whether KPTI is in use.
The trampoline code needs to use the address of symbols in the wider
kernel, e.g. vectors. PC-relative addressing wouldn't work as the
trampoline code doesn't run at the address the linker expected.
tramp_ventry uses a literal pool, unless CONFIG_RANDOMIZE_BASE is
set, in which case it uses the data page as a literal pool because
the data page can be unmapped when running in user-space, which is
required for CPUs vulnerable to meltdown.
Pull this logic out as a macro, instead of adding a third copy
of it.
Some CPUs affected by Spectre-BHB need a sequence of branches, or a
firmware call to be run before any indirect branch. This needs to go
in the vectors. No CPU needs both.
While this can be patched in, it would run on all CPUs as there is a
single set of vectors. If only one part of a big/little combination is
affected, the unaffected CPUs have to run the mitigation too.
Create extra vectors that include the sequence. Subsequent patches will
allow affected CPUs to select this set of vectors. Later patches will
modify the loop count to match what the CPU requires.
Adding a second set of vectors to .entry.tramp.text will make it
larger than a single 4K page.
Allow the trampoline text to occupy up to three pages by adding two
more fixmap slots. Previous changes to tramp_valias allowed it to reach
beyond a single page.