This is a note to let you know that I've just added the patch titled net: adjust skb->truesize in ___pskb_trim() to the 4.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-adjust-skb-truesize-in-___pskb_trim.patch and it can be found in the queue-4.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu May 11 10:37:58 CEST 2017 From: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Wed, 26 Apr 2017 09:07:46 -0700 Subject: net: adjust skb->truesize in ___pskb_trim() From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit c21b48cc1bbf2f5af3ef54ada559f7fadf8b508b ] Andrey found a way to trigger the WARN_ON_ONCE(delta < len) in skb_try_coalesce() using syzkaller and a filter attached to a TCP socket. As we did recently in commit 158f323b9868 ("net: adjust skb->truesize in pskb_expand_head()") we can adjust skb->truesize from ___pskb_trim(), via a call to skb_condense(). If all frags were freed, then skb->truesize can be recomputed. This call can be done if skb is not yet owned, or destructor is sock_edemux(). Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Cc: Willem de Bruijn <willemb@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/core/skbuff.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1572,6 +1572,8 @@ done: skb_set_tail_pointer(skb, len); } + if (!skb->sk || skb->destructor == sock_edemux) + skb_condense(skb); return 0; } EXPORT_SYMBOL(___pskb_trim); Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are queue-4.10/net-adjust-skb-truesize-in-___pskb_trim.patch queue-4.10/tcp-do-not-underestimate-skb-truesize-in-tcp_trim_head.patch queue-4.10/tcp-fix-wraparound-issue-in-tcp_lp.patch queue-4.10/tcp-do-not-inherit-fastopen_req-from-parent.patch