diff options
| author | Eric Dumazet <edumazet@google.com> | 2022-06-02 09:18:58 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-06-02 10:15:05 -0700 |
| commit | 22296a5c0cd35aaf62e1af3266f82cdf6b0b9b78 (patch) | |
| tree | 0f328bfb3dc7bcc9234d882d320c15603ca94107 /include/linux/skbuff.h | |
| parent | eb0b39efb7d908e3950f6f76ee6e3cecb86ec489 (diff) | |
| download | lwn-22296a5c0cd35aaf62e1af3266f82cdf6b0b9b78.tar.gz lwn-22296a5c0cd35aaf62e1af3266f82cdf6b0b9b78.zip | |
net: add debug info to __skb_pull()
While analyzing yet another syzbot report, I found the following
patch very useful. It allows to better understand what went wrong.
This debug info is only enabled if CONFIG_DEBUG_NET=y,
which is the case for syzbot builds.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux/skbuff.h')
| -rw-r--r-- | include/linux/skbuff.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index da96f0d3e753..d3d10556f0fa 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2696,7 +2696,14 @@ void *skb_pull(struct sk_buff *skb, unsigned int len); static inline void *__skb_pull(struct sk_buff *skb, unsigned int len) { skb->len -= len; - BUG_ON(skb->len < skb->data_len); + if (unlikely(skb->len < skb->data_len)) { +#if defined(CONFIG_DEBUG_NET) + skb->len += len; + pr_err("__skb_pull(len=%u)\n", len); + skb_dump(KERN_ERR, skb, false); +#endif + BUG(); + } return skb->data += len; } |