On Sat, Oct 21, 2017 at 9:56 PM, Wei Wei <dotwe...@gmail.com> wrote: > I have uploaded the VM core dump [1]. And I don’t know if these logs are > helpful in the case of > failing to get the C reproducer currently. > > [1] https://github.com/dotweiba/skb_clone_atomic_inc_bug/blob/master/vmcore.gz
Thanks. So this would be the atomic_inc on shb_shinfo(skb)->dataref, which matches the __ll_sc_atomic_add in Mark's trace. Debugging with crash shows 0xffff800071bb3180 and 0xffff800071bb2c80 to be valid skbuffs of len 40, no sk, both pointing to the same head. That is indeed unaligned: head = 0xffff8000327c80c9 "", end = 256, giving skb_shared_info at 0xffff8000327c81c9 and &skb_shared_info(skb)->dataref at 0xffff8000327c81c9 + 36 == 0xffff8000327c81ed
