CVE-2025-39866fs: writeback: fix use-after-free in __mark_inode_dirty()
Updated under an hour ago ()
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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
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Modified
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 15, 2026
Affected products
Linux Linux linux:linux (from the name) | from 0747259d13febfcc838980a63c414c9b920cea6f before e2a14bbae5d8bacaa301362744a110e2be40a3a3; from 0747259d13febfcc838980a63c414c9b920cea6f before b187c976111960e6e54a6b1fff724f6e3d39406c; 0747259d13febfcc838980a63c414c9b920cea6f builds before 1edc2feb9c759a9883dfe81cb5ed231412d8b2e4; from 0747259d13febfcc838980a63c414c9b920cea6f before bf89b1f87c72df79cf76203f71fbf8349cd5c9de; from 0747259d13febfcc838980a63c414c9b920cea6f before e63052921f1b25a836feb1500b841bff7a4a0456; from 0747259d13febfcc838980a63c414c9b920cea6f before c8c14adf80bd1a6e4a1d7ee9c2a816881c26d17a; from 0747259d13febfcc838980a63c414c9b920cea6f before d02d2c98d25793902f65803ab853b592c7a96b29 | CNA record |
Siemens SIMATIC CN 4100 siemens:simatic_cn_4100 (from the name) | before V5.0 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.5 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name) | from V3.1.5 | CISA ADP |
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.5 | CISA ADP |
linux linux_kernel linux:linux_kernel | from 4.2 before 5.10.247; from 5.11 before 5.15.192; from 5.16 before 6.1.151; from 6.2 before 6.6.105; from 6.7 before 6.12.46; from 6.13 before 6.16.6; 6.17; 6.17 | NVD |
debian debian_linux debian:debian_linux | 11.0 | NVD |
References
- https://git.kernel.org/stable/c/e2a14bbae5d8bacaa301362744a110e2be40a3a3patch
- https://git.kernel.org/stable/c/b187c976111960e6e54a6b1fff724f6e3d39406cpatch
- https://git.kernel.org/stable/c/1edc2feb9c759a9883dfe81cb5ed231412d8b2e4patch
- https://git.kernel.org/stable/c/bf89b1f87c72df79cf76203f71fbf8349cd5c9depatch
- https://git.kernel.org/stable/c/e63052921f1b25a836feb1500b841bff7a4a0456patch
- https://git.kernel.org/stable/c/c8c14adf80bd1a6e4a1d7ee9c2a816881c26d17apatch
- https://git.kernel.org/stable/c/d02d2c98d25793902f65803ab853b592c7a96b29patch
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.htmlthird-party-advisory
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.