net: drop bogus skb with CHECKSUM_PARTIAL and offset beyond end of trimmed packet
commit 54970a2f upstream. syzbot reproduces BUG_ON in skb_checksum_help(): tun creates (bogus) skb with huge partial-checksummed area and small ip packet inside. Then ip_rcv trims the skb based on size of internal ip packet, after that csum offset points beyond of trimmed skb. Then checksum_tg() called via netfilter hook triggers BUG_ON: offset = skb_checksum_start_offset(skb); BUG_ON(offset >= skb_headlen(skb)); To work around the problem this patch forces pskb_trim_rcsum_slow() to return -EINVAL in described scenario. It allows its callers to drop such kind of packets. Link: https://syzkaller.appspot.com/bug?id=b419a5ca95062664fe1a60b764621eb4526e2cd0 Reported-by:<syzbot+7010af67ced6105e5ab6@syzkaller.appspotmail.com> Signed-off-by:
Vasily Averin <vvs@virtuozzo.com> Acked-by:
Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/1b2494af-2c56-8ee2-7bc0-923fcad1cdf8@virtuozzo.com Signed-off-by:
Jakub Kicinski <kuba@kernel.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parent
b390ee66
Please register or sign in to comment