| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.10 107/129] net: adjust skb->truesize in ___pskb_trim() | Date | Thu, 11 May 2017 16:12:35 +0200 |
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4.10-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet <edumazet@google.com>
[ 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@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- 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);
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