From: Daniel Borkmann daniel@iogearbox.net
commit d203b0fd863a2261e5d00b97f3d060c4c2a6db71 upstream
Instead of relying on current env->pass_cnt, use the seen count from the old aux data in adjust_insn_aux_data(), and expand it to the new range of patched instructions. This change is valid given we always expand 1:n with n>=1, so what applies to the old/original instruction needs to apply for the replacement as well.
Not relying on env->pass_cnt is a prerequisite for a later change where we want to avoid marking an instruction seen when verified under speculative execution path.
Signed-off-by: Daniel Borkmann daniel@iogearbox.net Reviewed-by: John Fastabend john.fastabend@gmail.com Reviewed-by: Benedict Schlueter benedict.schlueter@rub.de Reviewed-by: Piotr Krysiuk piotras@gmail.com Acked-by: Alexei Starovoitov ast@kernel.org [OP: declare old_data as bool instead of u32 (struct bpf_insn_aux_data.seen is bool in 5.4)] Signed-off-by: Ovidiu Panait ovidiu.panait@windriver.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/bpf/verifier.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -8304,6 +8304,7 @@ static int adjust_insn_aux_data(struct b { struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data; struct bpf_insn *insn = new_prog->insnsi; + bool old_seen = old_data[off].seen; u32 prog_len; int i;
@@ -8324,7 +8325,8 @@ static int adjust_insn_aux_data(struct b memcpy(new_data + off + cnt - 1, old_data + off, sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1)); for (i = off; i < off + cnt - 1; i++) { - new_data[i].seen = true; + /* Expand insni[off]'s seen count to the patched range. */ + new_data[i].seen = old_seen; new_data[i].zext_dst = insn_has_def32(env, insn + i); } env->insn_aux_data = new_data;