diff options
| author | Rashika Kheria <rashika.kheria@gmail.com> | 2013-10-30 18:36:32 +0530 |
|---|---|---|
| committer | Alex Shi <alex.shi@linaro.org> | 2015-05-11 17:36:38 +0800 |
| commit | 3c073fe1e7f533e087a8e2faaff31f8b02e6aed9 (patch) | |
| tree | df730e8fd4444990a870f42fef1c531a92a40ed5 /drivers/staging | |
| parent | 922959916229ecc5f143b0fe66a9a8bbf4b55169 (diff) | |
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>
(cherry picked from commit 46a51c80216cb891f271ad021f59009f34677499)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Diffstat (limited to 'drivers/staging')
| -rw-r--r-- | drivers/staging/zram/zram_drv.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c index a125cfae6942..206f59d9a7a8 100644 --- a/drivers/staging/zram/zram_drv.c +++ b/drivers/staging/zram/zram_drv.c @@ -648,6 +648,9 @@ 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; @@ -660,8 +663,7 @@ 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; |