Description
In the Linux kernel, the following vulnerability has been resolved: fs: Protect reconfiguration of sb read-write from racing writes The reconfigure / remount code takes a lot of effort to protect filesystem's reconfiguration code from racing writes on remounting read-only. However during remounting read-only filesystem to read-write mode userspace writes can start immediately once we clear SB_RDONLY flag. This is inconvenient for example for ext4 because we need to do some writes to the filesystem (such as preparation of quota files) before we can take userspace writes so we are clearing SB_RDONLY flag before we are fully ready to accept userpace writes and syzbot has found a way to exploit this [1]. Also as far as I'm reading the code the filesystem remount code was protected from racing writes in the legacy mount path by the mount's MNT_READONLY flag so this is relatively new problem. It is actually fairly easy to protect remount read-write from racing writes using sb->s_readonly_remount flag so let's just do that instead of having to workaround these races in the filesystem code. [1] https://lore.kernel.org/all/[email protected]/T/
INFO
Published Date :
2025-12-24T13:06:25.895Z
Last Modified :
2026-01-05T10:33:44.627Z
Source :
Linux
AFFECTED PRODUCTS
The following products are affected by CVE-2023-54099 vulnerability.
| Vendors | Products |
|---|---|
| Linux |
|
REFERENCES
Here, you will find a curated list of external links that provide in-depth information to CVE-2023-54099.
