CVE-2026-74362 ext2: fix ignored return value of generic_write_sync()
A local attacker can cause data loss or corruption by exploiting ignored sync errors in the ext2 filesystem, leading to silent write failures.
- 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-2026-74362?
CVE-2026-74362 is a vulnerability in Linux, published on 15 Aug 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:
ext2: fix ignored return value of generic_write_sync()
Fix ext2_dio_write_iter() to propagate the error returned by generic_write_sync() instead of silently discarding it, which could cause write(2) to return success to userspace on O_SYNC/O_DSYNC files even when the sync failed.
The correct pattern, already used in ext2_dax_write_iter() in the same file and in ext4, xfs, f2fs among others, is: if (ret > 0) ret = generic_write_sync(iocb, ret);
Found by Linux Verification Center (linuxtesting.org) with SVACE.
[JK: Reflect also filemap_write_and_wait() return value]
Which versions are affected by CVE-2026-74362?
How do I fix CVE-2026-74362?
Apply the vendor's patch.
Is CVE-2026-74362 being exploited?
There is no known exploitation of CVE-2026-74362 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74362, DEBIAN-CVE-2026-74362, GHSA-v9mc-99cx-c56m, UBUNTU-CVE-2026-74362.