On 02/21/2013 11:44 AM, Roberts, Lee A. wrote:
From: Lee A. Roberts <lee.roberts@xxxxxx> Resolve SCTP association hangs observed during SCTP stress testing. Observable symptoms include communications hangs with data being held in the association lobby (ordering) queue. Close examination of reassembly/ordering queues shows duplicated packets. In sctp_tsnmap_grow(), correct off-by-one errors when copying and resizing the tsnmap. If max_tsn_seen is in the LSB of the word, this bit can be lost, causing the corresponding packet to be transmitted again and to be entered as a duplicate into the SCTP reassembly/ordering queues. Patch applies to linux-3.8 kernel. Signed-off-by: Lee A. Roberts <lee.roberts@xxxxxx> --- net/sctp/tsnmap.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff -uprN -X linux-3.8-vanilla/Documentation/dontdiff linux-3.8-vanilla/net/sctp/tsnmap.c linux-3.8-SCTP+1/net/sctp/tsnmap.c --- linux-3.8-vanilla/net/sctp/tsnmap.c 2013-02-18 16:58:34.000000000 -0700 +++ linux-3.8-SCTP+1/net/sctp/tsnmap.c 2013-02-20 08:01:02.555223259 -0700 @@ -369,14 +369,15 @@ static int sctp_tsnmap_grow(struct sctp_ if (gap >= SCTP_TSN_MAP_SIZE)
No that I think about this a bit more, this should be gap + 1. If you do that, you might as well call sctp_tsnmap_grow() with gap+1 as argument and then can just use the 'gap' everywhere inside.
return 0; - inc = ALIGN((gap - map->len),BITS_PER_LONG) + SCTP_TSN_MAP_INCREMENT; + inc = ALIGN((gap - map->len + 1), BITS_PER_LONG) + + SCTP_TSN_MAP_INCREMENT; len = min_t(u16, map->len + inc, SCTP_TSN_MAP_SIZE); new = kzalloc(len>>3, GFP_ATOMIC); if (!new) return 0; - bitmap_copy(new, map->tsn_map, map->max_tsn_seen - map->base_tsn); + bitmap_copy(new, map->tsn_map, map->max_tsn_seen - map->base_tsn + 1);
Can simplify that this by using map->cumulative_tsn_ack_point instead of base_tsn.
-vlad
kfree(map->tsn_map); map->tsn_map = new; map->len = len; -- 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
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