| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: add bounds checking to xlog_recover_process_data
There is a lack of verification of the space occupied by fixed members
of xlog_op_header in the xlog_recover_process_data.
We can create a crafted image to trigger an out of bounds read by
following these steps:
1) Mount an image of xfs, and do some file operations to leave records
2) Before umounting, copy the image for subsequent steps to simulate
abnormal exit. Because umount will ensure that tail_blk and
head_blk are the same, which will result in the inability to enter
xlog_recover_process_data
3) Write a tool to parse and modify the copied image in step 2
4) Make the end of the xlog_op_header entries only 1 byte away from
xlog_rec_header->h_size
5) xlog_rec_header->h_num_logops++
6) Modify xlog_rec_header->h_crc
Fix:
Add a check to make sure there is sufficient space to access fixed members
of xlog_op_header. |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: don't walk off the end of a directory data block
This adds sanity checks for xfs_dir2_data_unused and xfs_dir2_data_entry
to make sure don't stray beyond valid memory region. Before patching, the
loop simply checks that the start offset of the dup and dep is within the
range. So in a crafted image, if last entry is xfs_dir2_data_unused, we
can change dup->length to dup->length-1 and leave 1 byte of space. In the
next traversal, this space will be considered as dup or dep. We may
encounter an out of bound read when accessing the fixed members.
In the patch, we make sure that the remaining bytes large enough to hold
an unused entry before accessing xfs_dir2_data_unused and
xfs_dir2_data_unused is XFS_DIR2_DATA_ALIGN byte aligned. We also make
sure that the remaining bytes large enough to hold a dirent with a
single-byte name before accessing xfs_dir2_data_entry. |
| In the Linux kernel, the following vulnerability has been resolved:
netpoll: Fix race condition in netpoll_owner_active
KCSAN detected a race condition in netpoll:
BUG: KCSAN: data-race in net_rx_action / netpoll_send_skb
write (marked) to 0xffff8881164168b0 of 4 bytes by interrupt on cpu 10:
net_rx_action (./include/linux/netpoll.h:90 net/core/dev.c:6712 net/core/dev.c:6822)
<snip>
read to 0xffff8881164168b0 of 4 bytes by task 1 on cpu 2:
netpoll_send_skb (net/core/netpoll.c:319 net/core/netpoll.c:345 net/core/netpoll.c:393)
netpoll_send_udp (net/core/netpoll.c:?)
<snip>
value changed: 0x0000000a -> 0xffffffff
This happens because netpoll_owner_active() needs to check if the
current CPU is the owner of the lock, touching napi->poll_owner
non atomically. The ->poll_owner field contains the current CPU holding
the lock.
Use an atomic read to check if the poll owner is the current CPU. |
| In the Linux kernel, the following vulnerability has been resolved:
block/ioctl: prefer different overflow check
Running syzkaller with the newly reintroduced signed integer overflow
sanitizer shows this report:
[ 62.982337] ------------[ cut here ]------------
[ 62.985692] cgroup: Invalid name
[ 62.986211] UBSAN: signed-integer-overflow in ../block/ioctl.c:36:46
[ 62.989370] 9pnet_fd: p9_fd_create_tcp (7343): problem connecting socket to 127.0.0.1
[ 62.992992] 9223372036854775807 + 4095 cannot be represented in type 'long long'
[ 62.997827] 9pnet_fd: p9_fd_create_tcp (7345): problem connecting socket to 127.0.0.1
[ 62.999369] random: crng reseeded on system resumption
[ 63.000634] GUP no longer grows the stack in syz-executor.2 (7353): 20002000-20003000 (20001000)
[ 63.000668] CPU: 0 PID: 7353 Comm: syz-executor.2 Not tainted 6.8.0-rc2-00035-gb3ef86b5a957 #1
[ 63.000677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 63.000682] Call Trace:
[ 63.000686] <TASK>
[ 63.000731] dump_stack_lvl+0x93/0xd0
[ 63.000919] __get_user_pages+0x903/0xd30
[ 63.001030] __gup_longterm_locked+0x153e/0x1ba0
[ 63.001041] ? _raw_read_unlock_irqrestore+0x17/0x50
[ 63.001072] ? try_get_folio+0x29c/0x2d0
[ 63.001083] internal_get_user_pages_fast+0x1119/0x1530
[ 63.001109] iov_iter_extract_pages+0x23b/0x580
[ 63.001206] bio_iov_iter_get_pages+0x4de/0x1220
[ 63.001235] iomap_dio_bio_iter+0x9b6/0x1410
[ 63.001297] __iomap_dio_rw+0xab4/0x1810
[ 63.001316] iomap_dio_rw+0x45/0xa0
[ 63.001328] ext4_file_write_iter+0xdde/0x1390
[ 63.001372] vfs_write+0x599/0xbd0
[ 63.001394] ksys_write+0xc8/0x190
[ 63.001403] do_syscall_64+0xd4/0x1b0
[ 63.001421] ? arch_exit_to_user_mode_prepare+0x3a/0x60
[ 63.001479] entry_SYSCALL_64_after_hwframe+0x6f/0x77
[ 63.001535] RIP: 0033:0x7f7fd3ebf539
[ 63.001551] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
[ 63.001562] RSP: 002b:00007f7fd32570c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 63.001584] RAX: ffffffffffffffda RBX: 00007f7fd3ff3f80 RCX: 00007f7fd3ebf539
[ 63.001590] RDX: 4db6d1e4f7e43360 RSI: 0000000020000000 RDI: 0000000000000004
[ 63.001595] RBP: 00007f7fd3f1e496 R08: 0000000000000000 R09: 0000000000000000
[ 63.001599] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[ 63.001604] R13: 0000000000000006 R14: 00007f7fd3ff3f80 R15: 00007ffd415ad2b8
...
[ 63.018142] ---[ end trace ]---
Historically, the signed integer overflow sanitizer did not work in the
kernel due to its interaction with `-fwrapv` but this has since been
changed [1] in the newest version of Clang; It was re-enabled in the
kernel with Commit 557f8c582a9ba8ab ("ubsan: Reintroduce signed overflow
sanitizer").
Let's rework this overflow checking logic to not actually perform an
overflow during the check itself, thus avoiding the UBSAN splat.
[1]: https://github.com/llvm/llvm-project/pull/82432 |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix uninitialized ratelimit_state->lock access in __ext4_fill_super()
In the following concurrency we will access the uninitialized rs->lock:
ext4_fill_super
ext4_register_sysfs
// sysfs registered msg_ratelimit_interval_ms
// Other processes modify rs->interval to
// non-zero via msg_ratelimit_interval_ms
ext4_orphan_cleanup
ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
__ext4_msg
___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state)
if (!rs->interval) // do nothing if interval is 0
return 1;
raw_spin_trylock_irqsave(&rs->lock, flags)
raw_spin_trylock(lock)
_raw_spin_trylock
__raw_spin_trylock
spin_acquire(&lock->dep_map, 0, 1, _RET_IP_)
lock_acquire
__lock_acquire
register_lock_class
assign_lock_key
dump_stack();
ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
raw_spin_lock_init(&rs->lock);
// init rs->lock here
and get the following dump_stack:
=========================================================
INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 12 PID: 753 Comm: mount Tainted: G E 6.7.0-rc6-next-20231222 #504
[...]
Call Trace:
dump_stack_lvl+0xc5/0x170
dump_stack+0x18/0x30
register_lock_class+0x740/0x7c0
__lock_acquire+0x69/0x13a0
lock_acquire+0x120/0x450
_raw_spin_trylock+0x98/0xd0
___ratelimit+0xf6/0x220
__ext4_msg+0x7f/0x160 [ext4]
ext4_orphan_cleanup+0x665/0x740 [ext4]
__ext4_fill_super+0x21ea/0x2b10 [ext4]
ext4_fill_super+0x14d/0x360 [ext4]
[...]
=========================================================
Normally interval is 0 until s_msg_ratelimit_state is initialized, so
___ratelimit() does nothing. But registering sysfs precedes initializing
rs->lock, so it is possible to change rs->interval to a non-zero value
via the msg_ratelimit_interval_ms interface of sysfs while rs->lock is
uninitialized, and then a call to ext4_msg triggers the problem by
accessing an uninitialized rs->lock. Therefore register sysfs after all
initializations are complete to avoid such problems. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/radeon: fix UBSAN warning in kv_dpm.c
Adds bounds check for sumo_vid_mapping_entry. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix UBSAN warning in kv_dpm.c
Adds bounds check for sumo_vid_mapping_entry. |
| In the Linux kernel, the following vulnerability has been resolved:
batman-adv: bypass empty buckets in batadv_purge_orig_ref()
Many syzbot reports are pointing to soft lockups in
batadv_purge_orig_ref() [1]
Root cause is unknown, but we can avoid spending too much
time there and perhaps get more interesting reports.
[1]
watchdog: BUG: soft lockup - CPU#0 stuck for 27s! [kworker/u4:6:621]
Modules linked in:
irq event stamp: 6182794
hardirqs last enabled at (6182793): [<ffff8000801dae10>] __local_bh_enable_ip+0x224/0x44c kernel/softirq.c:386
hardirqs last disabled at (6182794): [<ffff80008ad66a78>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline]
hardirqs last disabled at (6182794): [<ffff80008ad66a78>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551
softirqs last enabled at (6182792): [<ffff80008aab71c4>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last enabled at (6182792): [<ffff80008aab71c4>] batadv_purge_orig_ref+0x114c/0x1228 net/batman-adv/originator.c:1287
softirqs last disabled at (6182790): [<ffff80008aab61dc>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (6182790): [<ffff80008aab61dc>] batadv_purge_orig_ref+0x164/0x1228 net/batman-adv/originator.c:1271
CPU: 0 PID: 621 Comm: kworker/u4:6 Not tainted 6.8.0-rc7-syzkaller-g707081b61156 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: bat_events batadv_purge_orig
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : should_resched arch/arm64/include/asm/preempt.h:79 [inline]
pc : __local_bh_enable_ip+0x228/0x44c kernel/softirq.c:388
lr : __local_bh_enable_ip+0x224/0x44c kernel/softirq.c:386
sp : ffff800099007970
x29: ffff800099007980 x28: 1fffe00018fce1bd x27: dfff800000000000
x26: ffff0000d2620008 x25: ffff0000c7e70de8 x24: 0000000000000001
x23: 1fffe00018e57781 x22: dfff800000000000 x21: ffff80008aab71c4
x20: ffff0001b40136c0 x19: ffff0000c72bbc08 x18: 1fffe0001a817bb0
x17: ffff800125414000 x16: ffff80008032116c x15: 0000000000000001
x14: 1fffe0001ee9d610 x13: 0000000000000000 x12: 0000000000000003
x11: 0000000000000000 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : 00000000005e5789 x7 : ffff80008aab61dc x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000006 x1 : 0000000000000080 x0 : ffff800125414000
Call trace:
__daif_local_irq_enable arch/arm64/include/asm/irqflags.h:27 [inline]
arch_local_irq_enable arch/arm64/include/asm/irqflags.h:49 [inline]
__local_bh_enable_ip+0x228/0x44c kernel/softirq.c:386
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
_raw_spin_unlock_bh+0x3c/0x4c kernel/locking/spinlock.c:210
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_purge_orig_ref+0x114c/0x1228 net/batman-adv/originator.c:1287
batadv_purge_orig+0x20/0x70 net/batman-adv/originator.c:1300
process_one_work+0x694/0x1204 kernel/workqueue.c:2633
process_scheduled_works kernel/workqueue.c:2706 [inline]
worker_thread+0x938/0xef4 kernel/workqueue.c:2787
kthread+0x288/0x310 kernel/kthread.c:388
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.8.0-rc7-syzkaller-g707081b61156 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : arch_local_irq_enable+0x8/0xc arch/arm64/include/asm/irqflags.h:51
lr : default_idle_call+0xf8/0x128 kernel/sched/idle.c:103
sp : ffff800093a17d30
x29: ffff800093a17d30 x28: dfff800000000000 x27: 1ffff00012742fb4
x26: ffff80008ec9d000 x25: 0000000000000000 x24: 0000000000000002
x23: 1ffff00011d93a74 x22: ffff80008ec9d3a0 x21: 0000000000000000
x20: ffff0000c19dbc00 x19: ffff8000802d0fd8 x18: 1fffe00036804396
x17: ffff80008ec9d000 x16: ffff8000802d089c x15: 0000000000000001
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: qedi: Fix crash while reading debugfs attribute
The qedi_dbg_do_not_recover_cmd_read() function invokes sprintf() directly
on a __user pointer, which results into the crash.
To fix this issue, use a small local stack buffer for sprintf() and then
call simple_read_from_buffer(), which in turns make the copy_to_user()
call.
BUG: unable to handle page fault for address: 00007f4801111000
PGD 8000000864df6067 P4D 8000000864df6067 PUD 864df7067 PMD 846028067 PTE 0
Oops: 0002 [#1] PREEMPT SMP PTI
Hardware name: HPE ProLiant DL380 Gen10/ProLiant DL380 Gen10, BIOS U30 06/15/2023
RIP: 0010:memcpy_orig+0xcd/0x130
RSP: 0018:ffffb7a18c3ffc40 EFLAGS: 00010202
RAX: 00007f4801111000 RBX: 00007f4801111000 RCX: 000000000000000f
RDX: 000000000000000f RSI: ffffffffc0bfd7a0 RDI: 00007f4801111000
RBP: ffffffffc0bfd7a0 R08: 725f746f6e5f6f64 R09: 3d7265766f636572
R10: ffffb7a18c3ffd08 R11: 0000000000000000 R12: 00007f4881110fff
R13: 000000007fffffff R14: ffffb7a18c3ffca0 R15: ffffffffc0bfd7af
FS: 00007f480118a740(0000) GS:ffff98e38af00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4801111000 CR3: 0000000864b8e001 CR4: 00000000007706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
? __die_body+0x1a/0x60
? page_fault_oops+0x183/0x510
? exc_page_fault+0x69/0x150
? asm_exc_page_fault+0x22/0x30
? memcpy_orig+0xcd/0x130
vsnprintf+0x102/0x4c0
sprintf+0x51/0x80
qedi_dbg_do_not_recover_cmd_read+0x2f/0x50 [qedi 6bcfdeeecdea037da47069eca2ba717c84a77324]
full_proxy_read+0x50/0x80
vfs_read+0xa5/0x2e0
? folio_add_new_anon_rmap+0x44/0xa0
? set_pte_at+0x15/0x30
? do_pte_missing+0x426/0x7f0
ksys_read+0xa5/0xe0
do_syscall_64+0x58/0x80
? __count_memcg_events+0x46/0x90
? count_memcg_event_mm+0x3d/0x60
? handle_mm_fault+0x196/0x2f0
? do_user_addr_fault+0x267/0x890
? exc_page_fault+0x69/0x150
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7f4800f20b4d |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/pseries: Enforce hcall result buffer validity and size
plpar_hcall(), plpar_hcall9(), and related functions expect callers to
provide valid result buffers of certain minimum size. Currently this
is communicated only through comments in the code and the compiler has
no idea.
For example, if I write a bug like this:
long retbuf[PLPAR_HCALL_BUFSIZE]; // should be PLPAR_HCALL9_BUFSIZE
plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, ...);
This compiles with no diagnostics emitted, but likely results in stack
corruption at runtime when plpar_hcall9() stores results past the end
of the array. (To be clear this is a contrived example and I have not
found a real instance yet.)
To make this class of error less likely, we can use explicitly-sized
array parameters instead of pointers in the declarations for the hcall
APIs. When compiled with -Warray-bounds[1], the code above now
provokes a diagnostic like this:
error: array argument is too small;
is of size 32, callee requires at least 72 [-Werror,-Warray-bounds]
60 | plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf,
| ^ ~~~~~~
[1] Enabled for LLVM builds but not GCC for now. See commit
0da6e5fd6c37 ("gcc: disable '-Warray-bounds' for gcc-13 too") and
related changes. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: do not create EA inode under buffer lock
ext4_xattr_set_entry() creates new EA inodes while holding buffer lock
on the external xattr block. This is problematic as it nests all the
allocation locking (which acquires locks on other buffers) under the
buffer lock. This can even deadlock when the filesystem is corrupted and
e.g. quota file is setup to contain xattr block as data block. Move the
allocation of EA inode out of ext4_xattr_set_entry() into the callers. |
| In the Linux kernel, the following vulnerability has been resolved:
Avoid hw_desc array overrun in dw-axi-dmac
I have a use case where nr_buffers = 3 and in which each descriptor is composed by 3
segments, resulting in the DMA channel descs_allocated to be 9. Since axi_desc_put()
handles the hw_desc considering the descs_allocated, this scenario would result in a
kernel panic (hw_desc array will be overrun).
To fix this, the proposal is to add a new member to the axi_dma_desc structure,
where we keep the number of allocated hw_descs (axi_desc_alloc()) and use it in
axi_desc_put() to handle the hw_desc array correctly.
Additionally I propose to remove the axi_chan_start_first_queued() call after completing
the transfer, since it was identified that unbalance can occur (started descriptors can
be interrupted and transfer ignored due to DMA channel not being enabled). |
| In the Linux kernel, the following vulnerability has been resolved:
MIPS: Octeon: Add PCIe link status check
The standard PCIe configuration read-write interface is used to
access the configuration space of the peripheral PCIe devices
of the mips processor after the PCIe link surprise down, it can
generate kernel panic caused by "Data bus error". So it is
necessary to add PCIe link status check for system protection.
When the PCIe link is down or in training, assigning a value
of 0 to the configuration address can prevent read-write behavior
to the configuration space of peripheral PCIe devices, thereby
preventing kernel panic. |
| In the Linux kernel, the following vulnerability has been resolved:
serial: imx: Introduce timeout when waiting on transmitter empty
By waiting at most 1 second for USR2_TXDC to be set, we avoid a potential
deadlock.
In case of the timeout, there is not much we can do, so we simply ignore
the transmitter state and optimistically try to continue. |
| In the Linux kernel, the following vulnerability has been resolved:
tty: add the option to have a tty reject a new ldisc
... and use it to limit the virtual terminals to just N_TTY. They are
kind of special, and in particular, the "con_write()" routine violates
the "writes cannot sleep" rule that some ldiscs rely on.
This avoids the
BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659
when N_GSM has been attached to a virtual console, and gsmld_write()
calls con_write() while holding a spinlock, and con_write() then tries
to get the console lock. |
| In the Linux kernel, the following vulnerability has been resolved:
i2c: lpi2c: Avoid calling clk_get_rate during transfer
Instead of repeatedly calling clk_get_rate for each transfer, lock
the clock rate and cache the value.
A deadlock has been observed while adding tlv320aic32x4 audio codec to
the system. When this clock provider adds its clock, the clk mutex is
locked already, it needs to access i2c, which in return needs the mutex
for clk_get_rate as well. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/exynos/vidi: fix memory leak in .get_modes()
The duplicated EDID is never freed. Fix it. |
| In the Linux kernel, the following vulnerability has been resolved:
parisc: Try to fix random segmentation faults in package builds
PA-RISC systems with PA8800 and PA8900 processors have had problems
with random segmentation faults for many years. Systems with earlier
processors are much more stable.
Systems with PA8800 and PA8900 processors have a large L2 cache which
needs per page flushing for decent performance when a large range is
flushed. The combined cache in these systems is also more sensitive to
non-equivalent aliases than the caches in earlier systems.
The majority of random segmentation faults that I have looked at
appear to be memory corruption in memory allocated using mmap and
malloc.
My first attempt at fixing the random faults didn't work. On
reviewing the cache code, I realized that there were two issues
which the existing code didn't handle correctly. Both relate
to cache move-in. Another issue is that the present bit in PTEs
is racy.
1) PA-RISC caches have a mind of their own and they can speculatively
load data and instructions for a page as long as there is a entry in
the TLB for the page which allows move-in. TLBs are local to each
CPU. Thus, the TLB entry for a page must be purged before flushing
the page. This is particularly important on SMP systems.
In some of the flush routines, the flush routine would be called
and then the TLB entry would be purged. This was because the flush
routine needed the TLB entry to do the flush.
2) My initial approach to trying the fix the random faults was to
try and use flush_cache_page_if_present for all flush operations.
This actually made things worse and led to a couple of hardware
lockups. It finally dawned on me that some lines weren't being
flushed because the pte check code was racy. This resulted in
random inequivalent mappings to physical pages.
The __flush_cache_page tmpalias flush sets up its own TLB entry
and it doesn't need the existing TLB entry. As long as we can find
the pte pointer for the vm page, we can get the pfn and physical
address of the page. We can also purge the TLB entry for the page
before doing the flush. Further, __flush_cache_page uses a special
TLB entry that inhibits cache move-in.
When switching page mappings, we need to ensure that lines are
removed from the cache. It is not sufficient to just flush the
lines to memory as they may come back.
This made it clear that we needed to implement all the required
flush operations using tmpalias routines. This includes flushes
for user and kernel pages.
After modifying the code to use tmpalias flushes, it became clear
that the random segmentation faults were not fully resolved. The
frequency of faults was worse on systems with a 64 MB L2 (PA8900)
and systems with more CPUs (rp4440).
The warning that I added to flush_cache_page_if_present to detect
pages that couldn't be flushed triggered frequently on some systems.
Helge and I looked at the pages that couldn't be flushed and found
that the PTE was either cleared or for a swap page. Ignoring pages
that were swapped out seemed okay but pages with cleared PTEs seemed
problematic.
I looked at routines related to pte_clear and noticed ptep_clear_flush.
The default implementation just flushes the TLB entry. However, it was
obvious that on parisc we need to flush the cache page as well. If
we don't flush the cache page, stale lines will be left in the cache
and cause random corruption. Once a PTE is cleared, there is no way
to find the physical address associated with the PTE and flush the
associated page at a later time.
I implemented an updated change with a parisc specific version of
ptep_clear_flush. It fixed the random data corruption on Helge's rp4440
and rp3440, as well as on my c8000.
At this point, I realized that I could restore the code where we only
flush in flush_cache_page_if_present if the page has been accessed.
However, for this, we also need to flush the cache when the accessed
bit is cleared in
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
jfs: xattr: fix buffer overflow for invalid xattr
When an xattr size is not what is expected, it is printed out to the
kernel log in hex format as a form of debugging. But when that xattr
size is bigger than the expected size, printing it out can cause an
access off the end of the buffer.
Fix this all up by properly restricting the size of the debug hex dump
in the kernel log. |
| In the Linux kernel, the following vulnerability has been resolved:
greybus: Fix use-after-free bug in gb_interface_release due to race condition.
In gb_interface_create, &intf->mode_switch_completion is bound with
gb_interface_mode_switch_work. Then it will be started by
gb_interface_request_mode_switch. Here is the relevant code.
if (!queue_work(system_long_wq, &intf->mode_switch_work)) {
...
}
If we call gb_interface_release to make cleanup, there may be an
unfinished work. This function will call kfree to free the object
"intf". However, if gb_interface_mode_switch_work is scheduled to
run after kfree, it may cause use-after-free error as
gb_interface_mode_switch_work will use the object "intf".
The possible execution flow that may lead to the issue is as follows:
CPU0 CPU1
| gb_interface_create
| gb_interface_request_mode_switch
gb_interface_release |
kfree(intf) (free) |
| gb_interface_mode_switch_work
| mutex_lock(&intf->mutex) (use)
Fix it by canceling the work before kfree. |
