diff options
| author | Xin Long <lucien.xin@gmail.com> | 2017-06-10 14:48:14 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-05 14:40:14 +0200 |
| commit | 8cda426a7cfa61b902c4335d1d1ab945bbcb41b6 (patch) | |
| tree | 8900faae7636e7960421a1b4d318529cd758df2d /net/sctp | |
| parent | c6d4ff85722b25877af48b311eda944dcc8c6feb (diff) | |
sctp: disable BH in sctp_for_each_endpoint
[ Upstream commit 581409dacc9176b0de1f6c4ca8d66e13aa8e1b29 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/sctp')
| -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 e1719c695174..0c5257efc6e4 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -4460,13 +4460,13 @@ 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; |