CVE-2026-63926

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.

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