CVE-2025-38710
Description
In the Linux kernel, the following vulnerability has been resolved: gfs2: Validate i_depth for exhash directories A fuzzer test introduced corruption that ends up with a depth of 0 in dir_e_read(), causing an undefined shift by 32 at: index = hash >> (32 - dip->i_depth); As calculated in an open-coded way in dir_make_exhash(), the minimum depth for an exhash directory is ilog2(sdp->sd_hash_ptrs) and 0 is invalid as sdp->sd_hash_ptrs is fixed as sdp->bsize / 16 at mount time. So we can avoid the undefined behaviour by checking for depth values lower than the minimum in gfs2_dinode_in(). Values greater than the maximum are already being checked for there. Also switch the calculation in dir_make_exhash() to use ilog2() to clarify how the depth is calculated. Tested with the syzkaller repro.c and xfstests '-g quick'.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Linux kernel Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | 6.12.43 |
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Mixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 6.12.43-1 |
| sid | Fixed | 6.16.3-1 |
| forky | Fixed | 6.16.3-1 |
| bullseye | Affected | — |
| bookworm | Affected | — |
References
- https://www.suse.com/security/cve/CVE-2025-38710.html
- https://security-tracker.debian.org/tracker/CVE-2025-38710
- https://git.kernel.org/stable/c/076e992752e4b24178918f748d75597c80a408d2
- https://git.kernel.org/stable/c/112bb60cd0e254a369e95aa9941a694ffeca089f
- https://git.kernel.org/stable/c/366183911b153e9b8cf758e1414e1154d7569337
- https://git.kernel.org/stable/c/53a0249d68a210c16e961b83adfa82f94ee0a53d
- https://git.kernel.org/stable/c/557c024ca7250bb65ae60f16c02074106c2f197b
- https://git.kernel.org/stable/c/9680c58675b82348ab84d387e4fa727f7587e1a0
- https://git.kernel.org/stable/c/b5f46951e62377b6e406fadc18bc3c5bdf1632a7
- https://git.kernel.org/stable/c/cddea0c721106ea480371412d8de21705eb27376
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.