diff mbox series

[-next] scsi: scsi_dh_alua: fix memleak for 'qdata' in alua_activate()

Message ID 20230315062154.668812-1-yukuai1@huaweicloud.com
State New
Headers show
Series [-next] scsi: scsi_dh_alua: fix memleak for 'qdata' in alua_activate() | expand

Commit Message

Yu Kuai March 15, 2023, 6:21 a.m. UTC 
From: Yu Kuai <yukuai3@huawei.com>

If alua_rtpg_queue() failed from alua_activate(), then 'qdata' is not
freed, which will cause following memleak:

unreferenced object 0xffff88810b2c6980 (size 32):
  comm "kworker/u16:2", pid 635322, jiffies 4355801099 (age 1216426.076s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    40 39 24 c1 ff ff ff ff 00 f8 ea 0a 81 88 ff ff  @9$.............
  backtrace:
    [<0000000098f3a26d>] alua_activate+0xb0/0x320
    [<000000003b529641>] scsi_dh_activate+0xb2/0x140
    [<000000007b296db3>] activate_path_work+0xc6/0xe0 [dm_multipath]
    [<000000007adc9ace>] process_one_work+0x3c5/0x730
    [<00000000c457a985>] worker_thread+0x93/0x650
    [<00000000cb80e628>] kthread+0x1ba/0x210
    [<00000000a1e61077>] ret_from_fork+0x22/0x30

Fix the problem by freeing 'qdata' in error path.

Fixes: 625fe857e4fa ("scsi: scsi_dh_alua: Check scsi_device_get() return value")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
 drivers/scsi/device_handler/scsi_dh_alua.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Bart Van Assche March 15, 2023, 4:51 p.m. UTC | #1 
On 3/14/23 23:21, Yu Kuai wrote:
> diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
> index 362fa631f39b..a226dc1b65d7 100644
> --- a/drivers/scsi/device_handler/scsi_dh_alua.c
> +++ b/drivers/scsi/device_handler/scsi_dh_alua.c
> @@ -1145,10 +1145,12 @@ static int alua_activate(struct scsi_device *sdev,
>   	rcu_read_unlock();
>   	mutex_unlock(&h->init_mutex);
>   
> -	if (alua_rtpg_queue(pg, sdev, qdata, true))
> +	if (alua_rtpg_queue(pg, sdev, qdata, true)) {
>   		fn = NULL;
> -	else
> +	} else {
> +		kfree(qdata);
>   		err = SCSI_DH_DEV_OFFLINED;
> +	}
>   	kref_put(&pg->kref, release_port_group);
>   out:
>   	if (fn)

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Martin K. Petersen March 17, 2023, 4:04 a.m. UTC | #2 
On Wed, 15 Mar 2023 14:21:54 +0800, Yu Kuai wrote:

> If alua_rtpg_queue() failed from alua_activate(), then 'qdata' is not
> freed, which will cause following memleak:
> 
> unreferenced object 0xffff88810b2c6980 (size 32):
>   comm "kworker/u16:2", pid 635322, jiffies 4355801099 (age 1216426.076s)
>   hex dump (first 32 bytes):
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>     40 39 24 c1 ff ff ff ff 00 f8 ea 0a 81 88 ff ff  @9$.............
>   backtrace:
>     [<0000000098f3a26d>] alua_activate+0xb0/0x320
>     [<000000003b529641>] scsi_dh_activate+0xb2/0x140
>     [<000000007b296db3>] activate_path_work+0xc6/0xe0 [dm_multipath]
>     [<000000007adc9ace>] process_one_work+0x3c5/0x730
>     [<00000000c457a985>] worker_thread+0x93/0x650
>     [<00000000cb80e628>] kthread+0x1ba/0x210
>     [<00000000a1e61077>] ret_from_fork+0x22/0x30
> 
> [...]

Applied to 6.3/scsi-fixes, thanks!

[1/1] scsi: scsi_dh_alua: fix memleak for 'qdata' in alua_activate()
      https://git.kernel.org/mkp/scsi/c/a13faca032ac
diff mbox series

Patch

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 362fa631f39b..a226dc1b65d7 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -1145,10 +1145,12 @@  static int alua_activate(struct scsi_device *sdev,
 	rcu_read_unlock();
 	mutex_unlock(&h->init_mutex);
 
-	if (alua_rtpg_queue(pg, sdev, qdata, true))
+	if (alua_rtpg_queue(pg, sdev, qdata, true)) {
 		fn = NULL;
-	else
+	} else {
+		kfree(qdata);
 		err = SCSI_DH_DEV_OFFLINED;
+	}
 	kref_put(&pg->kref, release_port_group);
 out:
 	if (fn)