CVE-2026-43359
Published: May 9, 2026Last modified: May 9, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix transaction abort on set received ioctl due to item overflow If the set received ioctl fails due to an item overflow when attempting to add the BTRFS_UUID_KEY_RECEIVED_SUBVOL we have to abort the transaction since we did some metadata updates before. This means that if a user calls this ioctl with the same received UUID field for a lot of subvolumes, we will hit the overflow, trigger the transaction abort and turn the filesystem into RO mode. A malicious user could exploit this, and this ioctl does not even requires that a user has admin privileges (CAP_SYS_ADMIN), only that he/she owns the subvolume. Fix this by doing an early check for item overflow before starting a transaction. This is also race safe because we are holding the subvol_sem semaphore in exclusive (write) mode. A test case for fstests will follow soon.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.5 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.167-r0) |
| 25 LTS | linux-lts | Fixed (6.12.80-r0) | |
| Stream | linux-lts | Fixed (6.12.80-r0) |
References
- https://git.kernel.org/stable/c/2e57b8cac2ba0d38aac76c1ecdfd8b899e3581a5
- https://git.kernel.org/stable/c/41fb97353ff58fa4f31904c343fc8e3df2f7517d
- https://git.kernel.org/stable/c/87f2c46003fce4d739138aab4af1942b1afdadac
- https://git.kernel.org/stable/c/b19c0465e4daad5aa8f60552ea0578cf31a11b1e
- https://git.kernel.org/stable/c/b9914db13ac15aca3b74544c0bb1a2e0dad1f174
- https://git.kernel.org/stable/c/d11aefe654a04fc41996d254748d6a38b6b0a7be