Merge branch 'bpf-fix-sock_ops_get_sk-same-register-oob-read-in-sock_ops-and-add...

Jiayuan Chen says:

====================
bpf: Fix SOCK_OPS_GET_SK same-register OOB read in sock_ops and add selftest

When a BPF sock_ops program accesses ctx fields with dst_reg == src_reg,
the SOCK_OPS_GET_SK() and SOCK_OPS_GET_FIELD() macros fail to zero the
destination register in the !fullsock / !locked_tcp_sock path, leading to
OOB read (GET_SK) and kernel pointer leak (GET_FIELD).

Patch 1: Fix both macros by adding BPF_MOV64_IMM(si->dst_reg, 0) in the
!fullsock landing pad.
Patch 2: Add selftests covering same-register and different-register cases
for both GET_SK and GET_FIELD.

[1] https://lore.kernel.org/bpf/6fe1243e-149b-4d3b-99c7-fcc9e2f75787@std.uestc.edu.cn/T/#u
====================

Link: https://patch.msgid.link/20260407022720.162151-1-jiayuan.chen@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>