diff options
| author | Sridhar Samudrala <sri@us.ibm.com> | 2006-01-17 11:56:26 -0800 |
|---|---|---|
| committer | Sridhar Samudrala <sri@us.ibm.com> | 2006-01-17 11:56:26 -0800 |
| commit | c4d2444e992c4eda1d7fc3287e93ba58295bf6b9 (patch) | |
| tree | 04f2096c141ede308356bd2d8277d4c291fae24d /net/sctp | |
| parent | 313e7b4d2588539e388d31c1febd50503a0083fc (diff) | |
| download | linux-c4d2444e992c4eda1d7fc3287e93ba58295bf6b9.tar.gz linux-c4d2444e992c4eda1d7fc3287e93ba58295bf6b9.tar.bz2 linux-c4d2444e992c4eda1d7fc3287e93ba58295bf6b9.zip | |
[SCTP]: Fix couple of races between sctp_peeloff() and sctp_rcv().
Validate and update the sk in sctp_rcv() to avoid the race where an
assoc/ep could move to a different socket after we get the sk, but before
the skb is added to the backlog.
Also migrate the skb's in backlog queue to new sk when doing a peeloff.
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Diffstat (limited to 'net/sctp')
| -rw-r--r-- | net/sctp/input.c | 35 | ||||
| -rw-r--r-- | net/sctp/socket.c | 4 |
2 files changed, 38 insertions, 1 deletions
diff --git a/net/sctp/input.c b/net/sctp/input.c index c463e4049c52..71fd56375641 100644 --- a/net/sctp/input.c +++ b/net/sctp/input.c @@ -257,12 +257,21 @@ int sctp_rcv(struct sk_buff *skb) */ sctp_bh_lock_sock(sk); + /* It is possible that the association could have moved to a different + * socket if it is peeled off. If so, update the sk. + */ + if (sk != rcvr->sk) { + sctp_bh_lock_sock(rcvr->sk); + sctp_bh_unlock_sock(sk); + sk = rcvr->sk; + } + if (sock_owned_by_user(sk)) sk_add_backlog(sk, skb); else sctp_backlog_rcv(sk, skb); - /* Release the sock and the sock ref we took in the lookup calls. + /* Release the sock and the sock ref we took in the lookup calls. * The asoc/ep ref will be released in sctp_backlog_rcv. */ sctp_bh_unlock_sock(sk); @@ -297,6 +306,9 @@ int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb) struct sctp_ep_common *rcvr = NULL; rcvr = chunk->rcvr; + + BUG_TRAP(rcvr->sk == sk); + if (rcvr->dead) { sctp_chunk_free(chunk); } else { @@ -313,6 +325,27 @@ int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb) return 0; } +void sctp_backlog_migrate(struct sctp_association *assoc, + struct sock *oldsk, struct sock *newsk) +{ + struct sk_buff *skb; + struct sctp_chunk *chunk; + + skb = oldsk->sk_backlog.head; + oldsk->sk_backlog.head = oldsk->sk_backlog.tail = NULL; + while (skb != NULL) { + struct sk_buff *next = skb->next; + + chunk = SCTP_INPUT_CB(skb)->chunk; + skb->next = NULL; + if (&assoc->base == chunk->rcvr) + sk_add_backlog(newsk, skb); + else + sk_add_backlog(oldsk, skb); + skb = next; + } +} + /* Handle icmp frag needed error. */ void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc, struct sctp_transport *t, __u32 pmtu) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 6a0b1af89932..fb1821d9f338 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -5602,8 +5602,12 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk, */ newsp->type = type; + spin_lock_bh(&oldsk->sk_lock.slock); + /* Migrate the backlog from oldsk to newsk. */ + sctp_backlog_migrate(assoc, oldsk, newsk); /* Migrate the association to the new socket. */ sctp_assoc_migrate(assoc, newsk); + spin_unlock_bh(&oldsk->sk_lock.slock); /* If the association on the newsk is already closed before accept() * is called, set RCV_SHUTDOWN flag. |