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.
