6.1-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 1fb2d41501f38192d8a19da585cd441cf8845697 ]
pskb_may_pull() can fail for two different reasons.
Provide pskb_may_pull_reason() helper to distinguish between these reasons.
It returns:
SKB_NOT_DROPPED_YET : Success SKB_DROP_REASON_PKT_TOO_SMALL : packet too small SKB_DROP_REASON_NOMEM : skb->head could not be resized
Signed-off-by: Eric Dumazet edumazet@google.com Reviewed-by: David Ahern dsahern@kernel.org Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: 8bd67ebb50c0 ("net: bridge: xmit: make sure we have at least eth header len bytes") Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/skbuff.h | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index cecd3b6bebb8b..2b54662048882 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2636,15 +2636,26 @@ void *skb_pull_data(struct sk_buff *skb, size_t len);
void *__pskb_pull_tail(struct sk_buff *skb, int delta);
-static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len) +static inline enum skb_drop_reason +pskb_may_pull_reason(struct sk_buff *skb, unsigned int len) { DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
if (likely(len <= skb_headlen(skb))) - return true; + return SKB_NOT_DROPPED_YET; + if (unlikely(len > skb->len)) - return false; - return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL; + return SKB_DROP_REASON_PKT_TOO_SMALL; + + if (unlikely(!__pskb_pull_tail(skb, len - skb_headlen(skb)))) + return SKB_DROP_REASON_NOMEM; + + return SKB_NOT_DROPPED_YET; +} + +static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len) +{ + return pskb_may_pull_reason(skb, len) == SKB_NOT_DROPPED_YET; }
static inline void *pskb_pull(struct sk_buff *skb, unsigned int len)