2015-06-24 01:33:52

by Asai Thambi SP

Subject: [PATCH] mtip32xx: Fix accessing freed memory

>From 4e5d695dca047012bc537c991fba0f85d112c614 Mon Sep 17 00:00:00 2001
From: Selvan Mani <[email protected]>
Date: Mon, 22 Jun 2015 02:18:48 -0700
Subject: [PATCH] mtip32xx: Fix accessing freed memory

In mtip_pci_remove(), driver data 'dd' is accessed after freeing it. This
is a residue of SRSI code cleanup in the patch 016a41c38821 "mtip32xx: fix
crash on surprise removal of the drive". Removed the bit flags
MTIP_DDF_REMOVE_DONE_BIT and MTIP_PF_SR_CLEANUP_BIT.

Reported-by: Julia Lawall <[email protected]>
Signed-off-by: Vignesh Gunasekaran <[email protected]>
Signed-off-by: Selvan Mani <[email protected]>
Signed-off-by: Asai Thambi S P <[email protected]>
---
drivers/block/mtip32xx/mtip32xx.c | 19 -------------------
drivers/block/mtip32xx/mtip32xx.h | 2 --
2 files changed, 21 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 144e7d9..4a2ef09 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -163,12 +163,6 @@ static bool mtip_check_surprise_removal(struct pci_dev *pdev)
else
dev_warn(&dd->pdev->dev,
"%s: dd->queue is NULL\n", __func__);
- if (dd->port) {
- set_bit(MTIP_PF_SR_CLEANUP_BIT, &dd->port->flags);
- wake_up_interruptible(&dd->port->svc_wait);
- } else
- dev_warn(&dd->pdev->dev,
- "%s: dd->port is NULL\n", __func__);
return true; /* device removed */
}

@@ -2938,10 +2932,6 @@ static int mtip_service_thread(void *data)
test_bit(MTIP_PF_SVC_THD_STOP_BIT, &port->flags))
goto st_out;

- /* If I am an orphan, start self cleanup */
- if (test_bit(MTIP_PF_SR_CLEANUP_BIT, &port->flags))
- break;
-
if (unlikely(test_bit(MTIP_DDF_REMOVE_PENDING_BIT,
&dd->dd_flag)))
goto st_out;
@@ -2995,14 +2985,6 @@ restart_eh:
}
}

- /* wait for pci remove to exit */
- while (1) {
- if (test_bit(MTIP_DDF_REMOVE_DONE_BIT, &dd->dd_flag))
- break;
- msleep_interruptible(1000);
- if (kthread_should_stop())
- goto st_out;
- }
st_out:
return 0;
}
@@ -4486,7 +4468,6 @@ static void mtip_pci_remove(struct pci_dev *pdev)
spin_unlock_irqrestore(&dev_lock, flags);

kfree(dd);
- set_bit(MTIP_DDF_REMOVE_DONE_BIT, &dd->dd_flag);

pcim_iounmap_regions(pdev, 1 << MTIP_ABAR);
pci_set_drvdata(pdev, NULL);
diff --git a/drivers/block/mtip32xx/mtip32xx.h b/drivers/block/mtip32xx/mtip32xx.h
index d7a5459..3274784 100644
--- a/drivers/block/mtip32xx/mtip32xx.h
+++ b/drivers/block/mtip32xx/mtip32xx.h
@@ -142,7 +142,6 @@ enum {
MTIP_PF_SVC_THD_ACTIVE_BIT = 4,
MTIP_PF_ISSUE_CMDS_BIT = 5,
MTIP_PF_REBUILD_BIT = 6,
- MTIP_PF_SR_CLEANUP_BIT = 7,
MTIP_PF_SVC_THD_STOP_BIT = 8,

/* below are bit numbers in 'dd_flag' defined in driver_data */
@@ -150,7 +149,6 @@ enum {
MTIP_DDF_REMOVE_PENDING_BIT = 1,
MTIP_DDF_OVER_TEMP_BIT = 2,
MTIP_DDF_WRITE_PROTECT_BIT = 3,
- MTIP_DDF_REMOVE_DONE_BIT = 4,
MTIP_DDF_CLEANUP_BIT = 5,
MTIP_DDF_RESUME_BIT = 6,
MTIP_DDF_INIT_DONE_BIT = 7,
--
2.0.1.537.g81e776d

2015-06-24 14:48:10

by Jens Axboe

Subject: Re: [PATCH] mtip32xx: Fix accessing freed memory

On 06/23/2015 07:32 PM, Asai Thambi SP wrote:
> From 4e5d695dca047012bc537c991fba0f85d112c614 Mon Sep 17 00:00:00 2001
> From: Selvan Mani <[email protected]>
> Date: Mon, 22 Jun 2015 02:18:48 -0700
> Subject: [PATCH] mtip32xx: Fix accessing freed memory
>
> In mtip_pci_remove(), driver data 'dd' is accessed after freeing it. This
> is a residue of SRSI code cleanup in the patch 016a41c38821 "mtip32xx: fix
> crash on surprise removal of the drive". Removed the bit flags
> MTIP_DDF_REMOVE_DONE_BIT and MTIP_PF_SR_CLEANUP_BIT.

Thanks, applied.

--
Jens Axboe