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BUG_ON(offset >= skb_headlen(skb)); This patch drops CHEKSUM_PARTIAL mark when skb is trimmed below size of checksummed area. Link: https://syzkaller.appspot.com/bug?id=b419a5ca95062664fe1a60b764621eb4526e2cd0 Reported-by: syzbot+7010af67ced6105e5ab6@syzkaller.appspotmail.com Signed-off-by: Vasily Averin --- include/linux/skbuff.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index a828cf9..0a9545d 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3419,9 +3419,18 @@ static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len) static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) { + int ret; + if (likely(len >= skb->len)) return 0; - return pskb_trim_rcsum_slow(skb, len); + ret = pskb_trim_rcsum_slow(skb, len); + if (!ret && (skb->ip_summed == CHECKSUM_PARTIAL)) { + int offset = skb_checksum_start_offset(skb) + skb->csum_offset; + + if (offset + sizeof(__sum16) > skb_headlen(skb)) + skb->ip_summed = CHECKSUM_NONE; + } + return ret; } static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len) -- 1.8.3.1