From 70fc69bc5a54d9776ace7c99d46eb533f8fb6e89 Mon Sep 17 00:00:00 2001 From: "Lee A. Roberts" Date: Thu, 28 Feb 2013 04:37:27 +0000 Subject: sctp: fix association hangs due to off-by-one errors in sctp_tsnmap_grow() In sctp_tsnmap_mark(), correct off-by-one error when calculating size value for sctp_tsnmap_grow(). In sctp_tsnmap_grow(), correct off-by-one error 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. Change parameter name from "gap" (zero-based index) to "size" (one-based) to enhance code readability. Signed-off-by: Lee A. Roberts Acked-by: Vlad Yasevich Acked-by: Neil Horman --- net/sctp/tsnmap.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'net') diff --git a/net/sctp/tsnmap.c b/net/sctp/tsnmap.c index 5f25e0c92c3..396c45174e5 100644 --- a/net/sctp/tsnmap.c +++ b/net/sctp/tsnmap.c @@ -51,7 +51,7 @@ static void sctp_tsnmap_update(struct sctp_tsnmap *map); static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off, __u16 len, __u16 *start, __u16 *end); -static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 gap); +static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 size); /* Initialize a block of memory as a tsnmap. */ struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *map, __u16 len, @@ -124,7 +124,7 @@ int sctp_tsnmap_mark(struct sctp_tsnmap *map, __u32 tsn, gap = tsn - map->base_tsn; - if (gap >= map->len && !sctp_tsnmap_grow(map, gap)) + if (gap >= map->len && !sctp_tsnmap_grow(map, gap + 1)) return -ENOMEM; if (!sctp_tsnmap_has_gap(map) && gap == 0) { @@ -360,23 +360,24 @@ __u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map, return ngaps; } -static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 gap) +static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 size) { unsigned long *new; unsigned long inc; u16 len; - if (gap >= SCTP_TSN_MAP_SIZE) + if (size > SCTP_TSN_MAP_SIZE) return 0; - inc = ALIGN((gap - map->len),BITS_PER_LONG) + SCTP_TSN_MAP_INCREMENT; + inc = ALIGN((size - map->len), 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->cumulative_tsn_ack_point); kfree(map->tsn_map); map->tsn_map = new; map->len = len; -- cgit v1.2.3