6.15-stable review patch. If anyone has any objections, please let me know.
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From: Eduard Zingerman eddyz87@gmail.com
[ Upstream commit 3157f7e2999616ac91f4d559a8566214f74000a5 ]
BPF_JSET is a conditional jump and currently verifier.c:can_jump() does not know about that. This can lead to incorrect live registers and SCC computation.
E.g. in the following example:
1: r0 = 1; 2: r2 = 2; 3: if r1 & 0x7 goto +1; 4: exit; 5: r0 = r2; 6: exit;
W/o this fix insn_successors(3) will return only (4), a jump to (5) would be missed and r2 won't be marked as alive at (3).
Fixes: 14c8552db644 ("bpf: simple DFA-based live registers analysis") Reported-by: syzbot+a36aac327960ff474804@syzkaller.appspotmail.com Suggested-by: Alexei Starovoitov alexei.starovoitov@gmail.com Signed-off-by: Eduard Zingerman eddyz87@gmail.com Link: https://lore.kernel.org/r/20250613175331.3238739-1-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/bpf/verifier.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index c12dfbeb78a7..a1ecad2944a8 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -23657,6 +23657,7 @@ static bool can_jump(struct bpf_insn *insn) case BPF_JSLT: case BPF_JSLE: case BPF_JCOND: + case BPF_JSET: return true; }