diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-11-05 20:43:57 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-11-07 04:29:14 +0300 |
| commit | 1e4033b53db48cc77c436feac9c6d7d63db87b87 (patch) | |
| tree | 01d711ab7fb8dcfa56a3e9c361ca55ff81feec1a /include | |
| parent | 3545f9b72f3e0edc43cd807a5c987656ca0a22aa (diff) | |
| download | linux-1e4033b53db48cc77c436feac9c6d7d63db87b87.tar.xz | |
net: skb_reset_mac_len() must check if mac_header was set
Recent discussions show that skb_reset_mac_len() should be more careful.
We expect the MAC header being set.
If not, clear skb->mac_len and fire a warning for CONFIG_DEBUG_NET=y builds.
If after investigations we find that not having a MAC header was okay,
we can remove the warning.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/netdev/CANn89iJZGH+yEfJxfPWa3Hm7jxb-aeY2Up4HufmLMnVuQXt38A@mail.gmail.com/T/
Cc: En-Wei Wu <en-wei.wu@canonical.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Link: https://patch.msgid.link/20241105174403.850330-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/skbuff.h | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 48f1e0fa2a13..5d8fefa71cac 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2909,9 +2909,19 @@ static inline void skb_reset_inner_headers(struct sk_buff *skb) skb->inner_transport_header = skb->transport_header; } +static inline int skb_mac_header_was_set(const struct sk_buff *skb) +{ + return skb->mac_header != (typeof(skb->mac_header))~0U; +} + static inline void skb_reset_mac_len(struct sk_buff *skb) { - skb->mac_len = skb->network_header - skb->mac_header; + if (!skb_mac_header_was_set(skb)) { + DEBUG_NET_WARN_ON_ONCE(1); + skb->mac_len = 0; + } else { + skb->mac_len = skb->network_header - skb->mac_header; + } } static inline unsigned char *skb_inner_transport_header(const struct sk_buff @@ -3014,11 +3024,6 @@ static inline void skb_set_network_header(struct sk_buff *skb, const int offset) skb->network_header += offset; } -static inline int skb_mac_header_was_set(const struct sk_buff *skb) -{ - return skb->mac_header != (typeof(skb->mac_header))~0U; -} - static inline unsigned char *skb_mac_header(const struct sk_buff *skb) { DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb)); |