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 /include/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 'include/net')
| -rw-r--r-- | include/net/lwtunnel.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h index 6f15e6fa154e..53bd2d02a4f0 100644 --- a/include/net/lwtunnel.h +++ b/include/net/lwtunnel.h @@ -16,9 +16,12 @@ #define LWTUNNEL_STATE_INPUT_REDIRECT BIT(1) #define LWTUNNEL_STATE_XMIT_REDIRECT BIT(2) +/* LWTUNNEL_XMIT_CONTINUE should be distinguishable from dst_output return + * values (NET_XMIT_xxx and NETDEV_TX_xxx in linux/netdevice.h) for safety. + */ enum { LWTUNNEL_XMIT_DONE, - LWTUNNEL_XMIT_CONTINUE, + LWTUNNEL_XMIT_CONTINUE = 0x100, }; |