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| author | Xin Long <lucien.xin@gmail.com> | 2017-06-10 14:48:14 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-06-10 16:18:10 -0400 |
| commit | 581409dacc9176b0de1f6c4ca8d66e13aa8e1b29 (patch) | |
| tree | 7364921671ba8789fec957642ed0835bf8953dfd | |
| parent | bf292f1b2c813f1d6ac49b04bd1a9863d8314266 (diff) | |
| download | op-kernel-dev-581409dacc9176b0de1f6c4ca8d66e13aa8e1b29.zip op-kernel-dev-581409dacc9176b0de1f6c4ca8d66e13aa8e1b29.tar.gz | |
sctp: disable BH in sctp_for_each_endpoint
Now sctp holds read_lock when foreach sctp_ep_hashtable without disabling
BH. If CPU schedules to another thread A at this moment, the thread A may
be trying to hold the write_lock with disabling BH.
As BH is disabled and CPU cannot schedule back to the thread holding the
read_lock, while the thread A keeps waiting for the read_lock. A dead
lock would be triggered by this.
This patch is to fix this dead lock by calling read_lock_bh instead to
disable BH when holding the read_lock in sctp_for_each_endpoint.
Fixes: 626d16f50f39 ("sctp: export some apis or variables for sctp_diag and reuse some for proc")
Reported-by: Xiumei Mu <xmu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/sctp/socket.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c index f16c8d9..30aa0a5 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -4622,13 +4622,13 @@ int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), for (head = sctp_ep_hashtable; hash < sctp_ep_hashsize; hash++, head++) { - read_lock(&head->lock); + read_lock_bh(&head->lock); sctp_for_each_hentry(epb, &head->chain) { err = cb(sctp_ep(epb), p); if (err) break; } - read_unlock(&head->lock); + read_unlock_bh(&head->lock); } return err; |
