Consider the following program:
r1 = map_value; /* low 32 bits are zero at runtime */
r6 = 0xdead000000000000;
if w1 != 0 goto l1;
l0: r1 += r6;
r2 = *(u64 *)(r1 + 0);
exit;
l1: r6 = 0;
goto l0;
At the moment is_branch_taken() reports the jump as always taken,
because it does not distinguish between BPF_JMP and BPF_JMP32
comparisons when processing 'if w1 != 0 ...'.
Fixes: cac616db39 ("bpf: Verifier track null pointer branch_taken with JNE and JEQ")
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-5-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
e51179a4e0