diff options
| author | Alexei Starovoitov <ast@fb.com> | 2016-09-01 18:37:21 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-09-02 10:46:44 -0700 |
| commit | ea2e7ce5d0fc878463ba39deb46cf2ab20398fd2 (patch) | |
| tree | 7b67c9e451afca1b570835bbd75d9be7aebc931e | |
| parent | 569e937e0100c8841619bd2150d15682141a6b0b (diff) | |
bpf: support 8-byte metafield access
The verifier supported only 4-byte metafields in
struct __sk_buff and struct xdp_md. The metafields in upcoming
struct bpf_perf_event are 8-byte to match register width in struct pt_regs.
Teach verifier to recognize 8-byte metafield access.
The patch doesn't affect safety of sockets and xdp programs.
They check for 4-byte only ctx access before these conditions are hit.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | kernel/bpf/verifier.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index abb61f3f6900..c1c9e441f0f5 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -2333,7 +2333,8 @@ static int do_check(struct verifier_env *env) if (err) return err; - if (BPF_SIZE(insn->code) != BPF_W) { + if (BPF_SIZE(insn->code) != BPF_W && + BPF_SIZE(insn->code) != BPF_DW) { insn_idx++; continue; } @@ -2642,9 +2643,11 @@ static int convert_ctx_accesses(struct verifier_env *env) for (i = 0; i < insn_cnt; i++, insn++) { u32 insn_delta, cnt; - if (insn->code == (BPF_LDX | BPF_MEM | BPF_W)) + if (insn->code == (BPF_LDX | BPF_MEM | BPF_W) || + insn->code == (BPF_LDX | BPF_MEM | BPF_DW)) type = BPF_READ; - else if (insn->code == (BPF_STX | BPF_MEM | BPF_W)) + else if (insn->code == (BPF_STX | BPF_MEM | BPF_W) || + insn->code == (BPF_STX | BPF_MEM | BPF_DW)) type = BPF_WRITE; else continue; |