In the Linux kernel, the following vulnerability has been resolved:
fs: writeback: fix use-after-free in __mark_inode_dirty()
An use-after-free issue occurred when __mark_inode_dirty() get the
bdi_writeback that was in the progress of switching.
CPU: 1 PID: 562 Comm: systemd-random- Not tainted 6.6.56-gb4403bd46a8e #1
......
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __mark_inode_dirty+0x124/0x418
lr : __mark_inode_dirty+0x118/0x418
sp : ffffffc08c9dbbc0
........
Call trace:
__mark_inode_dirty+0x124/0x418
generic_update_time+0x4c/0x60
file_modified+0xcc/0xd0
ext4_buffered_write_iter+0x58/0x124
ext4_file_write_iter+0x54/0x704
vfs_write+0x1c0/0x308
ksys_write+0x74/0x10c
__arm64_sys_write+0x1c/0x28
invoke_syscall+0x48/0x114
el0_svc_common.constprop.0+0xc0/0xe0
do_el0_svc+0x1c/0x28
el0_svc+0x40/0xe4
el0t_64_sync_handler+0x120/0x12c
el0t_64_sync+0x194/0x198
Root cause is:
systemd-random-seed kworker
----------------------------------------------------------------------
___mark_inode_dirty inode_switch_wbs_work_fn
spin_lock(&inode->i_lock);
inode_attach_wb
locked_inode_to_wb_and_lock_list
get inode->i_wb
spin_unlock(&inode->i_lock);
spin_lock(&wb->list_lock)
spin_lock(&inode->i_lock)
inode_io_list_move_locked
spin_unlock(&wb->list_lock)
spin_unlock(&inode->i_lock)
spin_lock(&old_wb->list_lock)
inode_do_switch_wbs
spin_lock(&inode->i_lock)
inode->i_wb = new_wb
spin_unlock(&inode->i_lock)
spin_unlock(&old_wb->list_lock)
wb_put_many(old_wb, nr_switched)
cgwb_release
old wb released
wb_wakeup_delayed() accesses wb,
then trigger the use-after-free
issue
Fix this race condition by holding inode spinlock until
wb_wakeup_delayed() finished.
References
Configurations
Configuration 1 (hide)
|
Configuration 2 (hide)
|
History
23 Jan 2026, 02:33
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.8 |
| References | () https://git.kernel.org/stable/c/1edc2feb9c759a9883dfe81cb5ed231412d8b2e4 - Patch | |
| References | () https://git.kernel.org/stable/c/b187c976111960e6e54a6b1fff724f6e3d39406c - Patch | |
| References | () https://git.kernel.org/stable/c/bf89b1f87c72df79cf76203f71fbf8349cd5c9de - Patch | |
| References | () https://git.kernel.org/stable/c/c8c14adf80bd1a6e4a1d7ee9c2a816881c26d17a - Patch | |
| References | () https://git.kernel.org/stable/c/d02d2c98d25793902f65803ab853b592c7a96b29 - Patch | |
| References | () https://git.kernel.org/stable/c/e2a14bbae5d8bacaa301362744a110e2be40a3a3 - Patch | |
| References | () https://git.kernel.org/stable/c/e63052921f1b25a836feb1500b841bff7a4a0456 - Patch | |
| References | () https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html - Third Party Advisory | |
| First Time |
Linux
Debian Debian debian Linux Linux linux Kernel |
|
| CWE | CWE-416 | |
| CPE | cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
06 Dec 2025, 22:15
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
03 Nov 2025, 18:16
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
19 Sep 2025, 16:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-09-19 16:15
Updated : 2026-01-23 02:33
NVD link : CVE-2025-39866
Mitre link : CVE-2025-39866
CVE.ORG link : CVE-2025-39866
JSON object : View
Products Affected
debian
- debian_linux
linux
- linux_kernel
CWE
CWE-416
Use After Free