2016-03-06 04:23:41

by Nicholas A. Bellinger

[permalink] [raw]
Subject: [PATCH] target: Drop incorrect ABORT_TASK put for completed commands

From: Nicholas Bellinger <[email protected]>

This patch fixes a recent ABORT_TASK regression associated
with commit febe562c, where a left-over target_put_sess_cmd()
would still be called when __target_check_io_state() detected
a command has already been completed, and explicit ABORT must
be avoided.

Note commit febe562c dropped the local kref_get_unless_zero()
check in core_tmr_abort_task(), but did not drop this extra
corresponding target_put_sess_cmd() in the failure path.

So go ahead and drop this now bogus target_put_sess_cmd(),
and avoid this potential use-after-free.

Reported-by: Dan Lane <[email protected]>
Cc: Quinn Tran <[email protected]>
Cc: Himanshu Madhani <[email protected]>
Cc: Sagi Grimberg <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Hannes Reinecke <[email protected]>
Cc: Andy Grover <[email protected]>
Cc: Mike Christie <[email protected]>
Signed-off-by: Nicholas Bellinger <[email protected]>
---
drivers/target/target_core_tmr.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index 82a663b..4f229e7 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -177,7 +177,6 @@ void core_tmr_abort_task(

if (!__target_check_io_state(se_cmd, se_sess, 0)) {
spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
- target_put_sess_cmd(se_cmd);
goto out;
}
list_del_init(&se_cmd->se_cmd_list);
--
1.9.1