diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2021-08-12 20:00:34 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-08-15 13:05:04 +0200 |
| commit | 0abc8c9754c953f5cd0ac7488c668ca8d53ffc90 (patch) | |
| tree | 69038a91dc5379064779916c7d99dc3f7f09e658 /kernel/bpf | |
| parent | 7c165d58effc19fdf68196d4ceebf940d5da777d (diff) | |
bpf: Inherit expanded/patched seen count from old aux data
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)
- adjusted context for 4.19]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/verifier.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 4ce032c4acd0..70cadee591f3 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5690,6 +5690,7 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env, u32 prog_len, u32 off, u32 cnt) { struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data; + bool old_seen = old_data[off].seen; int i; if (cnt == 1) @@ -5701,8 +5702,10 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env, u32 prog_len, memcpy(new_data, old_data, sizeof(struct bpf_insn_aux_data) * off); 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; + for (i = off; i < off + cnt - 1; i++) { + /* Expand insni[off]'s seen count to the patched range. */ + new_data[i].seen = old_seen; + } env->insn_aux_data = new_data; vfree(old_data); return 0; |