CVE-2026-98443
Published: October 20, 2026Last modified: November 3, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: xfs: fix cursor and pointer handling when recovering iunlink buckets LOLLM pointed out a bug in xlog_recover_iunlink_bucket: 1. We don't null out prev_ip after releasing it, which can lead to UAF problems if the inodegc flush call in the loop fails. at which point I noticed even more bugs: 2. If the inodegc flush inside the loop fails, we also leak @ip. 3. We set prev_agino to agino having already advanced agino, which results in inodes with i_prev_unlinked set to itself. 4. If we exit the bottom of the loop with prev_ip set, then prev_ip aliases ip and we also set its i_prev_unlinked to itself. Bugs 3 and 4 introduce loops into the unlinked list, though these loops don't surface because we immediately flush each unlinked inode after loading it. Fix all of these issues.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | REQUIRED |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.191-r0) |
| 25 LTS | linux-lts | Fixed (6.12.115-r0) | |
| Stream | linux-lts | Fixed (6.18.55-r0) |
References
- https://git.kernel.org/stable/c/47a948ba653a463d429e02fda2f06a3d6b78666d
- https://git.kernel.org/stable/c/65f39d09d73718611cee40399179323b5d4ead00
- https://git.kernel.org/stable/c/66a2179d02668f8df44b1a249899006f3ba38ea0
- https://git.kernel.org/stable/c/8c9d5b8a96d6b93eb24e07b4163c89341ba29bd1
- https://git.kernel.org/stable/c/8cfde7b2fb7288f4f6b90293e8702ff897c682fe
- https://git.kernel.org/stable/c/961c717e6bf0e53c2c2b1fe4aef1add9390fedab