diff options
| author | Yan Zhai <yan@cloudflare.com> | 2023-08-17 19:58:14 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2023-08-18 16:05:26 +0200 |
| commit | a171fbec88a2c730b108c7147ac5e7b2f5a02b47 (patch) | |
| tree | c6f4a953627411c1edf0832e135720e7ef5122ed /net | |
| parent | 29b22badb7a84b783e3a4fffca16f7768fb31205 (diff) | |
lwt: Check LWTUNNEL_XMIT_CONTINUE strictly
LWTUNNEL_XMIT_CONTINUE is implicitly assumed in ip(6)_finish_output2,
such that any positive return value from a xmit hook could cause
unexpected continue behavior, despite that related skb may have been
freed. This could be error-prone for future xmit hook ops. One of the
possible errors is to return statuses of dst_output directly.
To make the code safer, redefine LWTUNNEL_XMIT_CONTINUE value to
distinguish from dst_output statuses and check the continue
condition explicitly.
Fixes: 3a0af8fd61f9 ("bpf: BPF for lightweight tunnel infrastructure")
Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/96b939b85eda00e8df4f7c080f770970a4c5f698.1692326837.git.yan@cloudflare.com
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/ip_output.c | 2 | ||||
| -rw-r--r-- | net/ipv6/ip6_output.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index ce6257860a40..43ba4b77b248 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -216,7 +216,7 @@ static int ip_finish_output2(struct net *net, struct sock *sk, struct sk_buff *s if (lwtunnel_xmit_redirect(dst->lwtstate)) { int res = lwtunnel_xmit(skb); - if (res < 0 || res == LWTUNNEL_XMIT_DONE) + if (res != LWTUNNEL_XMIT_CONTINUE) return res; } diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index f8a1f6bb3f87..0665e8b09968 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -113,7 +113,7 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff * if (lwtunnel_xmit_redirect(dst->lwtstate)) { int res = lwtunnel_xmit(skb); - if (res < 0 || res == LWTUNNEL_XMIT_DONE) + if (res != LWTUNNEL_XMIT_CONTINUE) return res; } |