diff options
| author |   Lawrence Brakmo <brakmo@fb.com> | 2018-01-25 16:14:05 -0800 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2018-01-25 16:41:13 -0800 |
| commit | 2585cd62f0986a6e6d9c83363ed6dbcc66bc9f32 (patch) | |
| tree | c253c21199292459117b3e72e0a98701bab5c9fe /net/core | |
| parent | bpf, doc: Correct one wrong value in "Register value tracking" (diff) | |
| download | linux-dev-2585cd62f0986a6e6d9c83363ed6dbcc66bc9f32.tar.xz linux-dev-2585cd62f0986a6e6d9c83363ed6dbcc66bc9f32.zip | |
bpf: Only reply field should be writeable
Currently, a sock_ops BPF program can write the op field and all the
reply fields (reply and replylong). This is a bug. The op field should
not have been writeable and there is currently no way to use replylong
field for indices >= 1. This patch enforces that only the reply field
(which equals replylong[0]) is writeable.
Fixes: 40304b2a1567 ("bpf: BPF support for sock_ops")
Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/filter.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 18da42a81d0c..bf9bb755e369 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3845,8 +3845,7 @@ static bool sock_ops_is_valid_access(int off, int size, { if (type == BPF_WRITE) { switch (off) { - case offsetof(struct bpf_sock_ops, op) ... - offsetof(struct bpf_sock_ops, replylong[3]): + case offsetof(struct bpf_sock_ops, reply): break; default: return false; |