target: Drop signal_pending checks after interruptible lock acquire

Once upon a time, iscsit_get_tpg() was using an un-interruptible
lock.  The signal_pending() usage was a check to allow userspace
to break out of the operation with SIGINT.

AFAICT, there's no reason why this is necessary anymore, and as
reported by Alexey can be potentially dangerous.  Also, go ahead
and drop the other two problematic cases within iscsit_access_np()
and sbc_compare_and_write() as well.

Found by Linux Driver Verification project (linuxtesting.org).

Reported-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Nicholas Bellinger 2015-05-19 15:10:44 -07:00
parent 6c2faeaa0e
commit ee7619f2eb
3 changed files with 3 additions and 6 deletions

View File

@ -230,7 +230,7 @@ int iscsit_access_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
* Here we serialize access across the TIQN+TPG Tuple.
*/
ret = down_interruptible(&tpg->np_login_sem);
if ((ret != 0) || signal_pending(current))
if (ret != 0)
return -1;
spin_lock_bh(&tpg->tpg_state_lock);

View File

@ -161,10 +161,7 @@ struct iscsi_portal_group *iscsit_get_tpg_from_np(
int iscsit_get_tpg(
struct iscsi_portal_group *tpg)
{
int ret;
ret = mutex_lock_interruptible(&tpg->tpg_access_lock);
return ((ret != 0) || signal_pending(current)) ? -1 : 0;
return mutex_lock_interruptible(&tpg->tpg_access_lock);
}
void iscsit_put_tpg(struct iscsi_portal_group *tpg)

View File

@ -568,7 +568,7 @@ sbc_compare_and_write(struct se_cmd *cmd)
* comparision using SGLs at cmd->t_bidi_data_sg..
*/
rc = down_interruptible(&dev->caw_sem);
if ((rc != 0) || signal_pending(current)) {
if (rc != 0) {
cmd->transport_complete_callback = NULL;
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}