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| author | Xiaotian Feng <xtfeng@gmail.com> | 2012-12-13 16:12:18 +0800 |
|---|---|---|
| committer | Jeff Garzik <jgarzik@redhat.com> | 2012-12-14 09:40:34 -0500 |
| commit | 26cd4d65deba587f3cf2329b6869ce02bcbe68ec (patch) | |
| tree | e62b5a258bca2f0fe17b79771a75f053d1a90119 /drivers/ata/libata-scsi.c | |
| parent | 39f80acb9fe5adff216bde33c554e4bf5f6eec12 (diff) | |
| download | talos-obmc-linux-26cd4d65deba587f3cf2329b6869ce02bcbe68ec.tar.gz talos-obmc-linux-26cd4d65deba587f3cf2329b6869ce02bcbe68ec.zip | |
[libata] fix Null pointer dereference on disk error
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>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata/libata-scsi.c')
| -rw-r--r-- | drivers/ata/libata-scsi.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index a6df6a351d6e..7c337e754dab 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: |
