On Wed, Dec 03, 2014 at 12:13:58PM +0100, Daniel Borkmann wrote: > 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> > --- > net/sctp/output.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/sctp/output.c b/net/sctp/output.c > index 42dffd4..fc5e45b 100644 > --- a/net/sctp/output.c > +++ b/net/sctp/output.c > @@ -401,12 +401,12 @@ int sctp_packet_transmit(struct sctp_packet *packet) > 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. > -- > 1.7.11.7 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
