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| author | Rashika Kheria <rashika.kheria@gmail.com> | 2013-10-30 18:36:32 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-30 09:36:53 -0700 |
| commit | 46a51c80216cb891f271ad021f59009f34677499 (patch) | |
| tree | ad2a3d08f22a598477780baaad4eb6f7ebc38480 /drivers/staging | |
| parent | 59d3fe540454dd8fc48d4eda44e200f9c98bef10 (diff) | |
| download | linux-46a51c80216cb891f271ad021f59009f34677499.tar.gz | |
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.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 b704d06943f5..79ce363b2ea9 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; |