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authorRashika Kheria <rashika.kheria@gmail.com>2013-10-30 18:36:32 +0530
committerSimon Shields <keepcalm444@gmail.com>2016-06-12 21:19:51 +1000
commit895ec41cfb21cb9983209689da392e41d1390efb (patch)
tree00a47aa369f4724b35b98e77146cdee394c25567 /drivers/staging
parentbae6d9d2927a7bc7f0531c5d55f411cabc5f57cc (diff)
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Staging: zram: Fix access of NULL pointer
This patch fixes the bug in reset_store caused by accessing NULL pointer. The bdev gets its value from bdget_disk() which could fail when memory pressure is severe and hence can return NULL because allocation of inode in bdget could fail. Hence, this patch introduces a check for bdev to prevent reference to a NULL pointer in the later part of the code. It also removes unnecessary check of bdev for fsync_bdev(). Cc: stable <stable@vger.kernel.org> Acked-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging')
-rw-r--r--drivers/staging/zram/zram_drv.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index 06f217e6c63..5c56b382f05 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -659,6 +659,9 @@ static ssize_t reset_store(struct device *dev,
zram = dev_to_zram(dev);
bdev = bdget_disk(zram->disk, 0);
+ if (!bdev)
+ return -ENOMEM;
+
/* Do not reset an active device! */
if (bdev->bd_holders)
return -EBUSY;
@@ -671,8 +674,7 @@ static ssize_t reset_store(struct device *dev,
return -EINVAL;
/* Make sure all pending I/O is finished */
- if (bdev)
- fsync_bdev(bdev);
+ fsync_bdev(bdev);
zram_reset_device(zram, true);
return len;