CVE-2025-39866

HIGH EPSS 20.3%
Published Sep 19, 20259mo ago · Modified Jun 17, 20261w ago
7.8 CVSS 3.1
High
Find Similar
Published Sep 19, 2025 9mo ago
Last Modified Jun 17, 2026 1w ago

Description

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.

CVSS Details

Base Score
7.8
Exploitability
1.8
Impact
5.9
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
20.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-416 Use After Free Memory Safety

Affected Products 9

VendorProductVersionRange
linuxlinux_kernel*≥4.2  –  <5.10.247
linuxlinux_kernel*≥5.11  –  <5.15.192
linuxlinux_kernel*≥5.16  –  <6.1.151
linuxlinux_kernel*≥6.2  –  <6.6.105
linuxlinux_kernel*≥6.7  –  <6.12.46
linuxlinux_kernel*≥6.13  –  <6.16.6
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any
debiandebian_linux11.0any

References 10

  • cert-portal.siemens.com https://cert-portal.siemens.com/productcert/html/ssa-032379.html
  • cert-portal.siemens.com https://cert-portal.siemens.com/productcert/html/ssa-082556.html
  • git.kernel.org https://git.kernel.org/stable/c/1edc2feb9c759a9883dfe81cb5ed231412d8b2e4
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b187c976111960e6e54a6b1fff724f6e3d39406c
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/bf89b1f87c72df79cf76203f71fbf8349cd5c9de
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c8c14adf80bd1a6e4a1d7ee9c2a816881c26d17a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/d02d2c98d25793902f65803ab853b592c7a96b29
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e2a14bbae5d8bacaa301362744a110e2be40a3a3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e63052921f1b25a836feb1500b841bff7a4a0456
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
    Third Party Advisory

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/1edc2feb9c759a9883dfe81cb5ed231412d8b2e4
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b187c976111960e6e54a6b1fff724f6e3d39406c
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/bf89b1f87c72df79cf76203f71fbf8349cd5c9de
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c8c14adf80bd1a6e4a1d7ee9c2a816881c26d17a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/d02d2c98d25793902f65803ab853b592c7a96b29
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e2a14bbae5d8bacaa301362744a110e2be40a3a3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e63052921f1b25a836feb1500b841bff7a4a0456
    Patch