CVE-2026-23265 f2fs: fix to do sanity check on node footer in {read,write}_end_io
A missing sanity check in the Linux kernel f2fs filesystem allows a local attacker to cause a kernel panic via a corrupted image, resulting in denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-23265?
CVE-2026-23265 is a medium-severity denial of service vulnerability in Linux kernel, published on 18 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to do sanity check on node footer in {read,write}_end_io
-----------[ cut here ]------------ kernel BUG at fs/f2fs/data.c:358! Call Trace: <IRQ> blk_update_request+0x5eb/0xe70 block/blk-mq.c:987 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1149 blk_complete_reqs block/blk-mq.c:1224 [inline] blk_done_softirq+0x107/0x160 block/blk-mq.c:1229 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 </IRQ>
In f2fs_write_end_io(), it detects there is inconsistency in between node page index (nid) and footer.nid of node page.
If footer of node page is corrupted in fuzzed image, then we load corrupted node page w/ async method, e.g. f2fs_ra_node_pages() or f2fs_ra_node_page(), in where we won't do sanity check on node footer, once node page becomes dirty, we will encounter this bug after node page writeback.
Which versions are affected by CVE-2026-23265?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23265?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-23265 being exploited?
There is no known exploitation of CVE-2026-23265 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-23265, DEBIAN-CVE-2026-23265, GHSA-h5gx-jh73-27w4, ROOT-OS-DEBIAN-11-CVE-2026-23265, ROOT-OS-DEBIAN-12-CVE-2026-23265, ROOT-OS-DEBIAN-13-CVE-2026-23265 and 3 more.