Patchwork [3.5.y.z,extended,stable] Patch "fix Null pointer dereference on disk error" has been added to staging queue

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Submitter Herton Ronaldo Krzesinski
Date Jan. 7, 2013, 8:39 p.m.
Message ID <1357591140-22647-1-git-send-email-herton.krzesinski@canonical.com>
Download mbox | patch
Permalink /patch/210229/
State New
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Herton Ronaldo Krzesinski - Jan. 7, 2013, 8:39 p.m.
This is a note to let you know that I have just added a patch titled

    fix Null pointer dereference on disk error

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

From dcbf712139f34fac1f55bd8377d308c5cef8503c Mon Sep 17 00:00:00 2001
From: Xiaotian Feng <xtfeng@gmail.com>
Date: Thu, 13 Dec 2012 16:12:18 +0800
Subject: [PATCH] fix Null pointer dereference on disk error

commit 26cd4d65deba587f3cf2329b6869ce02bcbe68ec upstream.

Following oops were observed when disk error happened:

[ 4272.896937] sd 0:0:0:0: [sda] Unhandled error code
[ 4272.896939] sd 0:0:0:0: [sda] Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK
[ 4272.896942] sd 0:0:0:0: [sda] CDB: Read(10): 28 00 00 5a de a7 00 00 08 00
[ 4272.896951] end_request: I/O error, dev sda, sector 5955239
[ 4291.574947] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 4291.658305] IP: [] ahci_activity_show+0x1/0x40
[ 4291.730090] PGD 76dbbc067 PUD 6c4fba067 PMD 0
[ 4291.783408] Oops: 0000 [#1] SMP
[ 4291.822100] last sysfs file: /sys/devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/sw_activity
[ 4291.934235] CPU 9
[ 4291.958301] Pid: 27942, comm: hwinfo ......

ata_scsi_find_dev could return NULL, so ata_scsi_activity_{show,store} should check if atadev is NULL.

Signed-off-by: Xiaotian Feng <dannyfeng@tencent.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
---
 drivers/ata/libata-scsi.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--
1.7.9.5

Patch

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 2222635..15863a4 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -309,7 +309,8 @@  ata_scsi_activity_show(struct device *dev, struct device_attribute *attr,
 	struct ata_port *ap = ata_shost_to_port(sdev->host);
 	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);

-	if (ap->ops->sw_activity_show && (ap->flags & ATA_FLAG_SW_ACTIVITY))
+	if (atadev && ap->ops->sw_activity_show &&
+	    (ap->flags & ATA_FLAG_SW_ACTIVITY))
 		return ap->ops->sw_activity_show(atadev, buf);
 	return -EINVAL;
 }
@@ -324,7 +325,8 @@  ata_scsi_activity_store(struct device *dev, struct device_attribute *attr,
 	enum sw_activity val;
 	int rc;

-	if (ap->ops->sw_activity_store && (ap->flags & ATA_FLAG_SW_ACTIVITY)) {
+	if (atadev && ap->ops->sw_activity_store &&
+	    (ap->flags & ATA_FLAG_SW_ACTIVITY)) {
 		val = simple_strtoul(buf, NULL, 0);
 		switch (val) {
 		case OFF: case BLINK_ON: case BLINK_OFF: