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| author | Alex Dewar <alex.dewar90@gmail.com> | 2020-10-12 18:09:53 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-10-15 21:05:23 +0200 |
| commit | 83c11c17553c0fca217105c17444c4ef5ab2403f (patch) | |
| tree | 8f1cdaab67e2766fd7d76e634098dc03ce1caf07 /net/core | |
| parent | 8a3feed90e75283f15f830b1051bf048e4127c91 (diff) | |
net, sockmap: Don't call bpf_prog_put() on NULL pointer
If bpf_prog_inc_not_zero() fails for skb_parser, then bpf_prog_put() is
called unconditionally on skb_verdict, even though it may be NULL. Fix
and tidy up error path.
Fixes: 743df8b7749f ("bpf, sockmap: Check skb_verdict and skb_parser programs explicitly")
Addresses-Coverity-ID: 1497799: Null pointer dereferences (FORWARD_NULL)
Signed-off-by: Alex Dewar <alex.dewar90@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20201012170952.60750-1-alex.dewar90@gmail.com
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/sock_map.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 203900a6ca5f..ddc899e83313 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -238,17 +238,18 @@ static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs, int ret; skb_verdict = READ_ONCE(progs->skb_verdict); - skb_parser = READ_ONCE(progs->skb_parser); if (skb_verdict) { skb_verdict = bpf_prog_inc_not_zero(skb_verdict); if (IS_ERR(skb_verdict)) return PTR_ERR(skb_verdict); } + + skb_parser = READ_ONCE(progs->skb_parser); if (skb_parser) { skb_parser = bpf_prog_inc_not_zero(skb_parser); if (IS_ERR(skb_parser)) { - bpf_prog_put(skb_verdict); - return PTR_ERR(skb_parser); + ret = PTR_ERR(skb_parser); + goto out_put_skb_verdict; } } @@ -257,7 +258,7 @@ static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs, msg_parser = bpf_prog_inc_not_zero(msg_parser); if (IS_ERR(msg_parser)) { ret = PTR_ERR(msg_parser); - goto out; + goto out_put_skb_parser; } } @@ -311,11 +312,12 @@ out_drop: out_progs: if (msg_parser) bpf_prog_put(msg_parser); -out: - if (skb_verdict) - bpf_prog_put(skb_verdict); +out_put_skb_parser: if (skb_parser) bpf_prog_put(skb_parser); +out_put_skb_verdict: + if (skb_verdict) + bpf_prog_put(skb_verdict); return ret; } |