diff options
| author | Joern Engel <joern@logfs.org> | 2013-05-13 16:30:06 -0400 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-05-15 01:47:35 -0700 |
| commit | ccf5ae83a6cf3d9cfe9a7038bfe7cd38ab03d5e1 (patch) | |
| tree | cb3966328bce7584d4c24434490dc21a67ecb48b /drivers/target | |
| parent | a1321ddd27e65c6ada5b9a12cae4ee2612d76893 (diff) | |
target: close target_put_sess_cmd() vs. core_tmr_abort_task() race
It is possible for one thread to to take se_sess->sess_cmd_lock in
core_tmr_abort_task() before taking a reference count on
se_cmd->cmd_kref, while another thread in target_put_sess_cmd() drops
se_cmd->cmd_kref before taking se_sess->sess_cmd_lock.
This introduces kref_put_spinlock_irqsave() and uses it in
target_put_sess_cmd() to close the race window.
Signed-off-by: Joern Engel <joern@logfs.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target')
| -rw-r--r-- | drivers/target/target_core_transport.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index c3477fa6094..4a793362309 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -2211,21 +2211,19 @@ static void target_release_cmd_kref(struct kref *kref) { struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref); struct se_session *se_sess = se_cmd->se_sess; - unsigned long flags; - spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); if (list_empty(&se_cmd->se_cmd_list)) { - spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); + spin_unlock(&se_sess->sess_cmd_lock); se_cmd->se_tfo->release_cmd(se_cmd); return; } if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) { - spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); + spin_unlock(&se_sess->sess_cmd_lock); complete(&se_cmd->cmd_wait_comp); return; } list_del(&se_cmd->se_cmd_list); - spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); + spin_unlock(&se_sess->sess_cmd_lock); se_cmd->se_tfo->release_cmd(se_cmd); } @@ -2236,7 +2234,8 @@ static void target_release_cmd_kref(struct kref *kref) */ int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd) { - return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref); + return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref, + &se_sess->sess_cmd_lock); } EXPORT_SYMBOL(target_put_sess_cmd); |