This is a note to let you know that I've just added the patch titled
sctp: fix the panic caused by route update
to the 4.8-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:
sctp-fix-the-panic-caused-by-route-update.patch
and it can be found in the queue-4.8 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 Nov 10 16:43:03 CET 2016
From: Xin Long <lucien.xin@xxxxxxxxx>
Date: Mon, 24 Oct 2016 01:01:09 +0800
Subject: sctp: fix the panic caused by route update
From: Xin Long <lucien.xin@xxxxxxxxx>
[ Upstream commit ecc515d7238f2cffac839069d56dc271141defa0 ]
Commit 7303a1475008 ("sctp: identify chunks that need to be fragmented
at IP level") made the chunk be fragmented at IP level in the next round
if it's size exceed PMTU.
But there still is another case, PMTU can be updated if transport's dst
expires and transport's pmtu_pending is set in sctp_packet_transmit. If
the new PMTU is less than the chunk, the same issue with that commit can
be triggered.
So we should drop this packet and let it retransmit in another round
where it would be fragmented at IP level.
This patch is to fix it by checking the chunk size after PMTU may be
updated and dropping this packet if it's size exceed PMTU.
Fixes: 90017accff61 ("sctp: Add GSO support")
Signed-off-by: Xin Long <lucien.xin@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 | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -417,6 +417,7 @@ int sctp_packet_transmit(struct sctp_pac
__u8 has_data = 0;
int gso = 0;
int pktcount = 0;
+ int auth_len = 0;
struct dst_entry *dst;
unsigned char *auth = NULL; /* pointer to auth in skb data */
@@ -505,7 +506,12 @@ int sctp_packet_transmit(struct sctp_pac
list_for_each_entry(chunk, &packet->chunk_list, list) {
int padded = WORD_ROUND(chunk->skb->len);
- if (pkt_size + padded > tp->pathmtu)
+ if (chunk == packet->auth)
+ auth_len = padded;
+ else if (auth_len + padded + packet->overhead >
+ tp->pathmtu)
+ goto nomem;
+ else if (pkt_size + padded > tp->pathmtu)
break;
pkt_size += padded;
}
Patches currently in stable-queue which might be from lucien.xin@xxxxxxxxx are
queue-4.8/sctp-validate-chunk-len-before-actually-using-it.patch
queue-4.8/sctp-fix-the-panic-caused-by-route-update.patch
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