Linux: >> Linux Kernel >> 6.1.44 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid panic once fallocation fails for pinfile
syzbot reports a f2fs bug as below:
------------[ cut here ]------------
kernel BUG at fs/f2fs/segment.c:2746!
CPU: 0 UID: 0 PID: 5323 Comm: syz.0.0 Not tainted 6.13.0-rc2-syzkaller-00018-g7cb1b4663150 #0
RIP: 0010:get_new_segment fs/f2fs/segment.c:2746 [inline]
RIP: 0010:new_curseg+0x1f52/0x1f70 fs/f2fs/segment.c:2876
Call Trace:
<TASK>
__allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3210
f2fs_allocate_new_section fs/f2fs/segment.c:3224 [inline]
f2fs_allocate_pinning_section+0xfa/0x4e0 fs/f2fs/segment.c:3238
f2fs_expand_inode_data+0x696/0xca0 fs/f2fs/file.c:1830
f2fs_fallocate+0x537/0xa10 fs/f2fs/file.c:1940
vfs_fallocate+0x569/0x6e0 fs/open.c:327
do_vfs_ioctl+0x258c/0x2e40 fs/ioctl.c:885
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl+0x80/0x170 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Concurrent pinfile allocation may run out of free section, result in
panic in get_new_segment(), let's expand pin_sem lock coverage to
include f2fs_gc(), so that we can make sure to reclaim enough free
space for following allocation.
In addition, do below changes to enhance error path handling:
- call f2fs_bug_on() only in non-pinfile allocation path in
get_new_segment().
- call reset_curseg_fields() to reset all fields of curseg in
new_curseg()
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
dlm: prevent NPD when writing a positive value to event_done
do_uevent returns the value written to event_done. In case it is a
positive value, new_lockspace would undo all the work, and lockspace
would not be set. __dlm_new_lockspace, however, would treat that
positive value as a success due to commit 8511a2728ab8 ("dlm: fix use
count with multiple joins").
Down the line, device_create_lockspace would pass that NULL lockspace to
dlm_find_lockspace_local, leading to a NULL pointer dereference.
Treating such positive values as successes prevents the problem. Given
this has been broken for so long, this is unlikely to break userspace
expectations.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
f2fs: quota: fix to avoid warning in dquot_writeback_dquots()
F2FS-fs (dm-59): checkpoint=enable has some unwritten data.
------------[ cut here ]------------
WARNING: CPU: 6 PID: 8013 at fs/quota/dquot.c:691 dquot_writeback_dquots+0x2fc/0x308
pc : dquot_writeback_dquots+0x2fc/0x308
lr : f2fs_quota_sync+0xcc/0x1c4
Call trace:
dquot_writeback_dquots+0x2fc/0x308
f2fs_quota_sync+0xcc/0x1c4
f2fs_write_checkpoint+0x3d4/0x9b0
f2fs_issue_checkpoint+0x1bc/0x2c0
f2fs_sync_fs+0x54/0x150
f2fs_do_sync_file+0x2f8/0x814
__f2fs_ioctl+0x1960/0x3244
f2fs_ioctl+0x54/0xe0
__arm64_sys_ioctl+0xa8/0xe4
invoke_syscall+0x58/0x114
checkpoint and f2fs_remount may race as below, resulting triggering warning
in dquot_writeback_dquots().
atomic write remount
- do_remount
- down_write(&sb->s_umount);
- f2fs_remount
- ioctl
- f2fs_do_sync_file
- f2fs_sync_fs
- f2fs_write_checkpoint
- block_operations
- locked = down_read_trylock(&sbi->sb->s_umount)
: fail to lock due to the write lock was held by remount
- up_write(&sb->s_umount);
- f2fs_quota_sync
- dquot_writeback_dquots
- WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount))
: trigger warning because s_umount lock was unlocked by remount
If checkpoint comes from mount/umount/remount/freeze/quotactl, caller of
checkpoint has already held s_umount lock, calling dquot_writeback_dquots()
in the context should be safe.
So let's record task to sbi->umount_lock_holder, so that checkpoint can
know whether the lock has held in the context or not by checking current
w/ it.
In addition, in order to not misrepresent caller of checkpoint, we should
not allow to trigger async checkpoint for those callers: mount/umount/remount/
freeze/quotactl.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath11k: update channel list in reg notifier instead reg worker
Currently when ath11k gets a new channel list, it will be processed
according to the following steps:
1. update new channel list to cfg80211 and queue reg_work.
2. cfg80211 handles new channel list during reg_work.
3. update cfg80211's handled channel list to firmware by
ath11k_reg_update_chan_list().
But ath11k will immediately execute step 3 after reg_work is just
queued. Since step 2 is asynchronous, cfg80211 may not have completed
handling the new channel list, which may leading to an out-of-bounds
write error:
BUG: KASAN: slab-out-of-bounds in ath11k_reg_update_chan_list
Call Trace:
ath11k_reg_update_chan_list+0xbfe/0xfe0 [ath11k]
kfree+0x109/0x3a0
ath11k_regd_update+0x1cf/0x350 [ath11k]
ath11k_regd_update_work+0x14/0x20 [ath11k]
process_one_work+0xe35/0x14c0
Should ensure step 2 is completely done before executing step 3. Thus
Wen raised patch[1]. When flag NL80211_REGDOM_SET_BY_DRIVER is set,
cfg80211 will notify ath11k after step 2 is done.
So enable the flag NL80211_REGDOM_SET_BY_DRIVER then cfg80211 will
notify ath11k after step 2 is done. At this time, there will be no
KASAN bug during the execution of the step 3.
[1] https://patchwork.kernel.org/project/linux-wireless/patch/20230201065313.27203-1-quic_wgong@quicinc.com/
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3
CVSS Score
7.8
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
thermal: int340x: Add NULL check for adev
Not all devices have an ACPI companion fwnode, so adev might be NULL.
This is similar to the commit cd2fd6eab480
("platform/x86: int3472: Check for adev == NULL").
Add a check for adev not being set and return -ENODEV in that case to
avoid a possible NULL pointer deref in int3402_thermal_probe().
Note, under the same directory, int3400_thermal_probe() has such a
check.
[ rjw: Subject edit, added Fixes: ]
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all()
There's issue as follows:
BUG: KASAN: use-after-free in ext4_xattr_inode_dec_ref_all+0x6ff/0x790
Read of size 4 at addr ffff88807b003000 by task syz-executor.0/15172
CPU: 3 PID: 15172 Comm: syz-executor.0
Call Trace:
__dump_stack lib/dump_stack.c:82 [inline]
dump_stack+0xbe/0xfd lib/dump_stack.c:123
print_address_description.constprop.0+0x1e/0x280 mm/kasan/report.c:400
__kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560
kasan_report+0x3a/0x50 mm/kasan/report.c:585
ext4_xattr_inode_dec_ref_all+0x6ff/0x790 fs/ext4/xattr.c:1137
ext4_xattr_delete_inode+0x4c7/0xda0 fs/ext4/xattr.c:2896
ext4_evict_inode+0xb3b/0x1670 fs/ext4/inode.c:323
evict+0x39f/0x880 fs/inode.c:622
iput_final fs/inode.c:1746 [inline]
iput fs/inode.c:1772 [inline]
iput+0x525/0x6c0 fs/inode.c:1758
ext4_orphan_cleanup fs/ext4/super.c:3298 [inline]
ext4_fill_super+0x8c57/0xba40 fs/ext4/super.c:5300
mount_bdev+0x355/0x410 fs/super.c:1446
legacy_get_tree+0xfe/0x220 fs/fs_context.c:611
vfs_get_tree+0x8d/0x2f0 fs/super.c:1576
do_new_mount fs/namespace.c:2983 [inline]
path_mount+0x119a/0x1ad0 fs/namespace.c:3316
do_mount+0xfc/0x110 fs/namespace.c:3329
__do_sys_mount fs/namespace.c:3540 [inline]
__se_sys_mount+0x219/0x2e0 fs/namespace.c:3514
do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x67/0xd1
Memory state around the buggy address:
ffff88807b002f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88807b002f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88807b003000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88807b003080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88807b003100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
Above issue happens as ext4_xattr_delete_inode() isn't check xattr
is valid if xattr is in inode.
To solve above issue call xattr_check_inode() check if xattr if valid
in inode. In fact, we can directly verify in ext4_iget_extra_inode(),
so that there is no divergent verification.
CVSS Score
7.1
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
md/raid1,raid10: don't ignore IO flags
If blk-wbt is enabled by default, it's found that raid write performance
is quite bad because all IO are throttled by wbt of underlying disks,
due to flag REQ_IDLE is ignored. And turns out this behaviour exist since
blk-wbt is introduced.
Other than REQ_IDLE, other flags should not be ignored as well, for
example REQ_META can be set for filesystems, clearing it can cause priority
reverse problems; And REQ_NOWAIT should not be cleared as well, because
io will wait instead of failing directly in underlying disks.
Fix those problems by keep IO flags from master bio.
Fises: f51d46d0e7cb ("md: add support for REQ_NOWAIT")
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
md: fix mddev uaf while iterating all_mddevs list
While iterating all_mddevs list from md_notify_reboot() and md_exit(),
list_for_each_entry_safe is used, and this can race with deletint the
next mddev, causing UAF:
t1:
spin_lock
//list_for_each_entry_safe(mddev, n, ...)
mddev_get(mddev1)
// assume mddev2 is the next entry
spin_unlock
t2:
//remove mddev2
...
mddev_free
spin_lock
list_del
spin_unlock
kfree(mddev2)
mddev_put(mddev1)
spin_lock
//continue dereference mddev2->all_mddevs
The old helper for_each_mddev() actually grab the reference of mddev2
while holding the lock, to prevent from being freed. This problem can be
fixed the same way, however, the code will be complex.
Hence switch to use list_for_each_entry, in this case mddev_put() can free
the mddev1 and it's not safe as well. Refer to md_seq_show(), also factor
out a helper mddev_put_locked() to fix this problem.
CVSS Score
7.8
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix potential deadloop in prepare_compress_overwrite()
Jan Prusakowski reported a kernel hang issue as below:
When running xfstests on linux-next kernel (6.14.0-rc3, 6.12) I
encountered a problem in generic/475 test where fsstress process
gets blocked in __f2fs_write_data_pages() and the test hangs.
The options I used are:
MKFS_OPTIONS -- -O compression -O extra_attr -O project_quota -O quota /dev/vdc
MOUNT_OPTIONS -- -o acl,user_xattr -o discard,compress_extension=* /dev/vdc /vdc
INFO: task kworker/u8:0:11 blocked for more than 122 seconds.
Not tainted 6.14.0-rc3-xfstests-lockdep #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0 state:D stack:0 pid:11 tgid:11 ppid:2 task_flags:0x4208160 flags:0x00004000
Workqueue: writeback wb_workfn (flush-253:0)
Call Trace:
<TASK>
__schedule+0x309/0x8e0
schedule+0x3a/0x100
schedule_preempt_disabled+0x15/0x30
__mutex_lock+0x59a/0xdb0
__f2fs_write_data_pages+0x3ac/0x400
do_writepages+0xe8/0x290
__writeback_single_inode+0x5c/0x360
writeback_sb_inodes+0x22f/0x570
wb_writeback+0xb0/0x410
wb_do_writeback+0x47/0x2f0
wb_workfn+0x5a/0x1c0
process_one_work+0x223/0x5b0
worker_thread+0x1d5/0x3c0
kthread+0xfd/0x230
ret_from_fork+0x31/0x50
ret_from_fork_asm+0x1a/0x30
</TASK>
The root cause is: once generic/475 starts toload error table to dm
device, f2fs_prepare_compress_overwrite() will loop reading compressed
cluster pages due to IO error, meanwhile it has held .writepages lock,
it can block all other writeback tasks.
Let's fix this issue w/ below changes:
- add f2fs_handle_page_eio() in prepare_compress_overwrite() to
detect IO error.
- detect cp_error earler in f2fs_read_multi_pages().
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
ax25: Remove broken autobind
Binding AX25 socket by using the autobind feature leads to memory leaks
in ax25_connect() and also refcount leaks in ax25_release(). Memory
leak was detected with kmemleak:
================================================================
unreferenced object 0xffff8880253cd680 (size 96):
backtrace:
__kmalloc_node_track_caller_noprof (./include/linux/kmemleak.h:43)
kmemdup_noprof (mm/util.c:136)
ax25_rt_autobind (net/ax25/ax25_route.c:428)
ax25_connect (net/ax25/af_ax25.c:1282)
__sys_connect_file (net/socket.c:2045)
__sys_connect (net/socket.c:2064)
__x64_sys_connect (net/socket.c:2067)
do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
================================================================
When socket is bound, refcounts must be incremented the way it is done
in ax25_bind() and ax25_setsockopt() (SO_BINDTODEVICE). In case of
autobind, the refcounts are not incremented.
This bug leads to the following issue reported by Syzkaller:
================================================================
ax25_connect(): syz-executor318 uses autobind, please contact jreuter@yaina.de
------------[ cut here ]------------
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 0 PID: 5317 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:31
Modules linked in:
CPU: 0 UID: 0 PID: 5317 Comm: syz-executor318 Not tainted 6.14.0-rc4-syzkaller-00278-gece144f151ac #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:31
...
Call Trace:
<TASK>
__refcount_dec include/linux/refcount.h:336 [inline]
refcount_dec include/linux/refcount.h:351 [inline]
ref_tracker_free+0x6af/0x7e0 lib/ref_tracker.c:236
netdev_tracker_free include/linux/netdevice.h:4302 [inline]
netdev_put include/linux/netdevice.h:4319 [inline]
ax25_release+0x368/0x960 net/ax25/af_ax25.c:1080
__sock_release net/socket.c:647 [inline]
sock_close+0xbc/0x240 net/socket.c:1398
__fput+0x3e9/0x9f0 fs/file_table.c:464
__do_sys_close fs/open.c:1580 [inline]
__se_sys_close fs/open.c:1565 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1565
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
...
</TASK>
================================================================
Considering the issues above and the comments left in the code that say:
"check if we can remove this feature. It is broken."; "autobinding in this
may or may not work"; - it is better to completely remove this feature than
to fix it because it is broken and leads to various kinds of memory bugs.
Now calling connect() without first binding socket will result in an
error (-EINVAL). Userspace software that relies on the autobind feature
might get broken. However, this feature does not seem widely used with
this specific driver as it was not reliable at any point of time, and it
is already broken anyway. E.g. ax25-tools and ax25-apps packages for
popular distributions do not use the autobind feature for AF_AX25.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-04-16