CVE-2026-63926
Published: July 22, 2026Last modified: July 22, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: sockmap: fix tail fragment offset in bpf_msg_push_data When bpf_msg_push_data() inserts data in the middle of a scatterlist entry, it splits the original entry into a left fragment and a right fragment. The right fragment offset is page-local, but the code advances it with `start`, which is the message-global insertion point. For inserts into a non-first SG entry, this over-advances the offset and leaves the split layout inconsistent. Advance the right fragment offset by the fragment-local delta, `start - offset`, which matches the length removed from the front of the original entry.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 8.4 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.177-r0) |
| 25 LTS | linux-lts | Fixed (6.12.95-r0) | |
| Stream | linux-lts | Fixed (6.18.35-r1) |
References
- https://git.kernel.org/stable/c/3075c21d2d76c0067f4a382765b43d6cc10470f1
- https://git.kernel.org/stable/c/5e19028667963fb371ebb00cecc2a473ef92056b
- https://git.kernel.org/stable/c/63f64a510c7917658ddf4d073ece73914ee25346
- https://git.kernel.org/stable/c/96b72672ce849a1402730238e64d9b20bf06a96d
- https://git.kernel.org/stable/c/aeb95146848d12206e1b2cfacd4f40e21ce81d94
- https://git.kernel.org/stable/c/d81b323af2dcee47573907ccb89c0df9b45cb2e2
- https://git.kernel.org/stable/c/f14609d8146707452e0822f3c8154674ce677251
- https://git.kernel.org/stable/c/f72eed9b84fb771019a955908132410a9ba9ea3f