This is a note to let you know that I've just added the patch titled net: sctp: use MAX_HEADER for headroom reserve in output path to the 3.14-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-sctp-use-max_header-for-headroom-reserve-in-output-path.patch and it can be found in the queue-3.14 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 Sun Dec 14 08:38:06 PST 2014 From: Daniel Borkmann <dborkman@xxxxxxxxxx> Date: Wed, 3 Dec 2014 12:13:58 +0100 Subject: net: sctp: use MAX_HEADER for headroom reserve in output path MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Daniel Borkmann <dborkman@xxxxxxxxxx> [ Upstream commit 9772b54c55266ce80c639a80aa68eeb908f8ecf5 ] To accomodate for enough headroom for tunnels, use MAX_HEADER instead of LL_MAX_HEADER. Robert reported that he has hit after roughly 40hrs of trinity an skb_under_panic() via SCTP output path (see reference). I couldn't reproduce it from here, but not using MAX_HEADER as elsewhere in other protocols might be one possible cause for this. In any case, it looks like accounting on chunks themself seems to look good as the skb already passed the SCTP output path and did not hit any skb_over_panic(). Given tunneling was enabled in his .config, the headroom would have been expanded by MAX_HEADER in this case. Reported-by: Robert Święcki <robert@xxxxxxxxxxx> Reference: https://lkml.org/lkml/2014/12/1/507 Fixes: 594ccc14dfe4d ("[SCTP] Replace incorrect use of dev_alloc_skb with alloc_skb in sctp_packet_transmit().") Signed-off-by: Daniel Borkmann <dborkman@xxxxxxxxxx> Acked-by: Vlad Yasevich <vyasevich@xxxxxxxxx> Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/sctp/output.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/sctp/output.c +++ b/net/sctp/output.c @@ -401,12 +401,12 @@ int sctp_packet_transmit(struct sctp_pac sk = chunk->skb->sk; /* Allocate the new skb. */ - nskb = alloc_skb(packet->size + LL_MAX_HEADER, GFP_ATOMIC); + nskb = alloc_skb(packet->size + MAX_HEADER, GFP_ATOMIC); if (!nskb) goto nomem; /* Make sure the outbound skb has enough header room reserved. */ - skb_reserve(nskb, packet->overhead + LL_MAX_HEADER); + skb_reserve(nskb, packet->overhead + MAX_HEADER); /* Set the owning socket so that we know where to get the * destination IP address. Patches currently in stable-queue which might be from dborkman@xxxxxxxxxx are queue-3.14/net-sctp-use-max_header-for-headroom-reserve-in-output-path.patch queue-3.14/ipv6-gre-fix-wrong-skb-protocol-in-wccp.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html