diff options
| author |   Daniel Axtens <dja@axtens.net> | 2018-03-03 03:03:46 +0100 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2018-03-03 13:01:11 -0800 |
| commit | d02f51cbcf12b09ab945873e35046045875eed9a (patch) | |
| tree | 986c3a4022275f49fde59e84ab1435ff738b8752 /include/linux/skbuff.h | |
| parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf (diff) | |
| download | linux-dev-d02f51cbcf12b09ab945873e35046045875eed9a.tar.xz linux-dev-d02f51cbcf12b09ab945873e35046045875eed9a.zip | |
bpf: fix bpf_skb_adjust_net/bpf_skb_proto_xlat to deal with gso sctp skbs
SCTP GSO skbs have a gso_size of GSO_BY_FRAGS, so any sort of
unconditionally mangling of that will result in nonsense value
and would corrupt the skb later on.
Therefore, i) add two helpers skb_increase_gso_size() and
skb_decrease_gso_size() that would throw a one time warning and
bail out for such skbs and ii) refuse and return early with an
error in those BPF helpers that are affected. We do need to bail
out as early as possible from there before any changes on the
skb have been performed.
Fixes: 6578171a7ff0 ("bpf: add bpf_skb_change_proto helper")
Co-authored-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include/linux/skbuff.h')
| -rw-r--r-- | include/linux/skbuff.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index c1e66bdcf583..8c67c33f40c9 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -4038,6 +4038,12 @@ static inline bool skb_is_gso_v6(const struct sk_buff *skb) return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; } +/* Note: Should be called only if skb_is_gso(skb) is true */ +static inline bool skb_is_gso_sctp(const struct sk_buff *skb) +{ + return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP; +} + static inline void skb_gso_reset(struct sk_buff *skb) { skb_shinfo(skb)->gso_size = 0; @@ -4045,6 +4051,22 @@ static inline void skb_gso_reset(struct sk_buff *skb) skb_shinfo(skb)->gso_type = 0; } +static inline void skb_increase_gso_size(struct skb_shared_info *shinfo, + u16 increment) +{ + if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS)) + return; + shinfo->gso_size += increment; +} + +static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo, + u16 decrement) +{ + if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS)) + return; + shinfo->gso_size -= decrement; +} + void __skb_warn_lro_forwarding(const struct sk_buff *skb); static inline bool skb_warn_if_lro(const struct sk_buff *skb) |