| Message ID | 20220620093017.3366713-1-eric.dumazet@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | f9aefd6b2aa38b9787d2705f0f1161dfd23cdb8f |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] net: warn if mac header was not set | expand |
Hello, On Mon, 2022-06-20 at 02:30 -0700, Eric Dumazet wrote: > From: Eric Dumazet <edumazet@google.com> > > Make sure skb_mac_header(), skb_mac_offset() and skb_mac_header_len() uses > are not fooled if the mac header has not been set. > > These checks are enabled if CONFIG_DEBUG_NET=y > > This commit will likely expose existing bugs in linux networking stacks. > > Signed-off-by: Eric Dumazet <edumazet@google.com> > --- > include/linux/skbuff.h | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index 82edf0359ab32d0d7cd583676b38d569ce0b24cc..cd4a8268894acce4bde16dc0fedb7eb13706f515 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -2763,8 +2763,14 @@ 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)); > return skb->head + skb->mac_header; > } > > @@ -2775,14 +2781,10 @@ static inline int skb_mac_offset(const struct sk_buff *skb) > > static inline u32 skb_mac_header_len(const struct sk_buff *skb) > { > + DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb)); The patch LGTM. I'm wondering if it's worthy adding similar debug checks for network and transport offset (with more patches). e.g. still in skb_mac_header_len(): DEBUG_NET_WARN_ON_ONCE(skb->network_header < skb->mac_header); Thanks! Paolo
Hello: This patch was applied to netdev/net-next.git (master) by Paolo Abeni <pabeni@redhat.com>: On Mon, 20 Jun 2022 02:30:17 -0700 you wrote: > From: Eric Dumazet <edumazet@google.com> > > Make sure skb_mac_header(), skb_mac_offset() and skb_mac_header_len() uses > are not fooled if the mac header has not been set. > > These checks are enabled if CONFIG_DEBUG_NET=y > > [...] Here is the summary with links: - [net-next] net: warn if mac header was not set https://git.kernel.org/netdev/net-next/c/f9aefd6b2aa3 You are awesome, thank you!
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 82edf0359ab32d0d7cd583676b38d569ce0b24cc..cd4a8268894acce4bde16dc0fedb7eb13706f515 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2763,8 +2763,14 @@ 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)); return skb->head + skb->mac_header; } @@ -2775,14 +2781,10 @@ static inline int skb_mac_offset(const struct sk_buff *skb) static inline u32 skb_mac_header_len(const struct sk_buff *skb) { + DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb)); return skb->network_header - skb->mac_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_unset_mac_header(struct sk_buff *skb) { skb->mac_header = (typeof(skb->mac_header))~0U;