[PATCH v3 3/4] sctp: fix association hangs due to errors when reneging events from the ordering queue
From: Lee A. Roberts <hidden>
Date: 2013-02-28 14:36:37
Also in:
linux-sctp
Subsystem:
networking [general], sctp protocol, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Marcelo Ricardo Leitner, Xin Long, Linus Torvalds
From: "Lee A. Roberts" <redacted> In sctp_ulpq_renege_list(), events being reneged from the ordering queue may correspond to multiple TSNs. Identify all affected packets; sum freed space and renege from the tsnmap. Signed-off-by: Lee A. Roberts <redacted> --- net/sctp/ulpqueue.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-)
diff --git a/net/sctp/ulpqueue.c b/net/sctp/ulpqueue.c
index 63afddc..f221fbb 100644
--- a/net/sctp/ulpqueue.c
+++ b/net/sctp/ulpqueue.c@@ -962,8 +962,8 @@ static __u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq, struct sk_buff_head *list, __u16 needed) { __u16 freed = 0; - __u32 tsn; - struct sk_buff *skb; + __u32 tsn, last_tsn; + struct sk_buff *skb, *flist, *last; struct sctp_ulpevent *event; struct sctp_tsnmap *tsnmap;
@@ -977,10 +977,28 @@ static __u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq, if (TSN_lte(tsn, sctp_tsnmap_get_ctsn(tsnmap))) break; - __skb_unlink(skb, list); + /* Events in ordering queue may have multiple fragments + * corresponding to additional TSNs. Sum the total + * freed space; find the last TSN. + */ freed += skb_headlen(skb); + flist = skb_shinfo(skb)->frag_list; + for (last = flist; flist; flist = flist->next) { + last = flist; + freed += skb_headlen(last); + } + if (last) + last_tsn = sctp_skb2event(last)->tsn; + else + last_tsn = tsn; + + /* Unlink the event, then renege all applicable TSNs. */ + __skb_unlink(skb, list); sctp_ulpevent_free(event); - sctp_tsnmap_renege(tsnmap, tsn); + while (TSN_lte(tsn, last_tsn)) { + sctp_tsnmap_renege(tsnmap, tsn); + tsn++; + } if (freed >= needed) return freed; }
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1.7.9.5