In the Linux kernel, the following vulnerability has been resolved:
ALSA: ac97: fix possible memory leak in snd_ac97_dev_register()
If device_register() fails in snd_ac97_dev_register(), it should
call put_device() to give up reference, or the name allocated in
dev_set_name() is leaked.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: aoa: i2sbus: fix possible memory leak in i2sbus_add_dev()
dev_set_name() in soundbus_add_one() allocates memory for name, it need be
freed when of_device_register() fails, call soundbus_dev_put() to give up
the reference that hold in device_initialize(), so that it can be freed in
kobject_cleanup() when the refcount hit to 0. And other resources are also
freed in i2sbus_release_dev(), so it can return 0 directly.
In the Linux kernel, the following vulnerability has been resolved:
scsi: libsas: Fix use-after-free bug in smp_execute_task_sg()
When executing SMP task failed, the smp_execute_task_sg() calls del_timer()
to delete "slow_task->timer". However, if the timer handler
sas_task_internal_timedout() is running, the del_timer() in
smp_execute_task_sg() will not stop it and a UAF will happen. The process
is shown below:
(thread 1) | (thread 2)
smp_execute_task_sg() | sas_task_internal_timedout()
... |
del_timer() |
... | ...
sas_free_task(task) |
kfree(task->slow_task) //FREE|
| task->slow_task->... //USE
Fix by calling del_timer_sync() in smp_execute_task_sg(), which makes sure
the timer handler have finished before the "task->slow_task" is
deallocated.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Fix UBSAN shift-out-of-bounds warning
If get_num_sdma_queues or get_num_xgmi_sdma_queues is 0, we end up
doing a shift operation where the number of bits shifted equals
number of bits in the operand. This behaviour is undefined.
Set num_sdma_queues or num_xgmi_sdma_queues to ULLONG_MAX, if the
count is >= number of bits in the operand.
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1472
In the Linux kernel, the following vulnerability has been resolved:
net: phylink: add lock for serializing concurrent pl->phydev writes with resolver
Currently phylink_resolve() protects itself against concurrent
phylink_bringup_phy() or phylink_disconnect_phy() calls which modify
pl->phydev by relying on pl->state_mutex.
The problem is that in phylink_resolve(), pl->state_mutex is in a lock
inversion state with pl->phydev->lock. So pl->phydev->lock needs to be
acquired prior to pl->state_mutex. But that requires dereferencing
pl->phydev in the first place, and without pl->state_mutex, that is
racy.
Hence the reason for the extra lock. Currently it is redundant, but it
will serve a functional purpose once mutex_lock(&phy->lock) will be
moved outside of the mutex_lock(&pl->state_mutex) section.
Another alternative considered would have been to let phylink_resolve()
acquire the rtnl_mutex, which is also held when phylink_bringup_phy()
and phylink_disconnect_phy() are called. But since phylink_disconnect_phy()
runs under rtnl_lock(), it would deadlock with phylink_resolve() when
calling flush_work(&pl->resolve). Additionally, it would have been
undesirable because it would have unnecessarily blocked many other call
paths as well in the entire kernel, so the smaller-scoped lock was
preferred.
In the Linux kernel, the following vulnerability has been resolved:
mm/slub: avoid accessing metadata when pointer is invalid in object_err()
object_err() reports details of an object for further debugging, such as
the freelist pointer, redzone, etc. However, if the pointer is invalid,
attempting to access object metadata can lead to a crash since it does
not point to a valid object.
One known path to the crash is when alloc_consistency_checks()
determines the pointer to the allocated object is invalid because of a
freelist corruption, and calls object_err() to report it. The debug code
should report and handle the corruption gracefully and not crash in the
process.
In case the pointer is NULL or check_valid_pointer() returns false for
the pointer, only print the pointer value and skip accessing metadata.
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix recursive semaphore deadlock in fiemap call
syzbot detected a OCFS2 hang due to a recursive semaphore on a
FS_IOC_FIEMAP of the extent list on a specially crafted mmap file.
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185
__down_write_common kernel/locking/rwsem.c:1317 [inline]
__down_write kernel/locking/rwsem.c:1326 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591
ocfs2_page_mkwrite+0x2ff/0xc40 fs/ocfs2/mmap.c:142
do_page_mkwrite+0x14d/0x310 mm/memory.c:3361
wp_page_shared mm/memory.c:3762 [inline]
do_wp_page+0x268d/0x5800 mm/memory.c:3981
handle_pte_fault mm/memory.c:6068 [inline]
__handle_mm_fault+0x1033/0x5440 mm/memory.c:6195
handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364
do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
RIP: 0010:raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline]
RIP: 0010:_inline_copy_to_user include/linux/uaccess.h:197 [inline]
RIP: 0010:_copy_to_user+0x85/0xb0 lib/usercopy.c:26
Code: e8 00 bc f7 fc 4d 39 fc 72 3d 4d 39 ec 77 38 e8 91 b9 f7 fc 4c 89
f7 89 de e8 47 25 5b fd 0f 01 cb 4c 89 ff 48 89 d9 4c 89 f6 <f3> a4 0f
1f 00 48 89 cb 0f 01 ca 48 89 d8 5b 41 5c 41 5d 41 5e 41
RSP: 0018:ffffc9000403f950 EFLAGS: 00050256
RAX: ffffffff84c7f101 RBX: 0000000000000038 RCX: 0000000000000038
RDX: 0000000000000000 RSI: ffffc9000403f9e0 RDI: 0000200000000060
RBP: ffffc9000403fa90 R08: ffffc9000403fa17 R09: 1ffff92000807f42
R10: dffffc0000000000 R11: fffff52000807f43 R12: 0000200000000098
R13: 00007ffffffff000 R14: ffffc9000403f9e0 R15: 0000200000000060
copy_to_user include/linux/uaccess.h:225 [inline]
fiemap_fill_next_extent+0x1c0/0x390 fs/ioctl.c:145
ocfs2_fiemap+0x888/0xc90 fs/ocfs2/extent_map.c:806
ioctl_fiemap fs/ioctl.c:220 [inline]
do_vfs_ioctl+0x1173/0x1430 fs/ioctl.c:532
__do_sys_ioctl fs/ioctl.c:596 [inline]
__se_sys_ioctl+0x82/0x170 fs/ioctl.c:584
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5f13850fd9
RSP: 002b:00007ffe3b3518b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000200000000000 RCX: 00007f5f13850fd9
RDX: 0000200000000040 RSI: 00000000c020660b RDI: 0000000000000004
RBP: 6165627472616568 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe3b3518f0
R13: 00007ffe3b351b18 R14: 431bde82d7b634db R15: 00007f5f1389a03b
ocfs2_fiemap() takes a read lock of the ip_alloc_sem semaphore (since
v2.6.22-527-g7307de80510a) and calls fiemap_fill_next_extent() to read the
extent list of this running mmap executable. The user supplied buffer to
hold the fiemap information page faults calling ocfs2_page_mkwrite() which
will take a write lock (since v2.6.27-38-g00dc417fa3e7) of the same
semaphore. This recursive semaphore will hold filesystem locks and causes
a hang of the fileystem.
The ip_alloc_sem protects the inode extent list and size. Release the
read semphore before calling fiemap_fill_next_extent() in ocfs2_fiemap()
and ocfs2_fiemap_inline(). This does an unnecessary semaphore lock/unlock
on the last extent but simplifies the error path.
In the Linux kernel, the following vulnerability has been resolved:
ppp: fix memory leak in pad_compress_skb
If alloc_skb() fails in pad_compress_skb(), it returns NULL without
releasing the old skb. The caller does:
skb = pad_compress_skb(ppp, skb);
if (!skb)
goto drop;
drop:
kfree_skb(skb);
When pad_compress_skb() returns NULL, the reference to the old skb is
lost and kfree_skb(skb) ends up doing nothing, leading to a memory leak.
Align pad_compress_skb() semantics with realloc(): only free the old
skb if allocation and compression succeed. At the call site, use the
new_skb variable so the original skb is not lost when pad_compress_skb()
fails.
In the Linux kernel, the following vulnerability has been resolved:
ax25: properly unshare skbs in ax25_kiss_rcv()
Bernard Pidoux reported a regression apparently caused by commit
c353e8983e0d ("net: introduce per netns packet chains").
skb->dev becomes NULL and we crash in __netif_receive_skb_core().
Before above commit, different kind of bugs or corruptions could happen
without a major crash.
But the root cause is that ax25_kiss_rcv() can queue/mangle input skb
without checking if this skb is shared or not.
Many thanks to Bernard Pidoux for his help, diagnosis and tests.
We had a similar issue years ago fixed with commit 7aaed57c5c28
("phonet: properly unshare skbs in phonet_rcv()").
In the Linux kernel, the following vulnerability has been resolved:
mfd: arizona: Use pm_runtime_resume_and_get() to prevent refcnt leak
In arizona_clk32k_enable(), we should use pm_runtime_resume_and_get()
as pm_runtime_get_sync() will increase the refcnt even when it
returns an error.