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| author | Rashika Kheria <rashika.kheria@gmail.com> | 2013-10-30 18:36:32 +0530 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-01-03 04:33:25 +0000 |
| commit | dccfb68c26308eb5fa3321110c9a4b51e89d67e3 (patch) | |
| tree | 97b5e61a39b8e3c9cd0b02572f4268a3df40e312 /drivers/staging | |
| parent | 653106814a7591093b28f23a5d0d207121672781 (diff) | |
| download | kernel_samsung_smdk4412-dccfb68c26308eb5fa3321110c9a4b51e89d67e3.zip kernel_samsung_smdk4412-dccfb68c26308eb5fa3321110c9a4b51e89d67e3.tar.gz kernel_samsung_smdk4412-dccfb68c26308eb5fa3321110c9a4b51e89d67e3.tar.bz2 | |
Staging: zram: Fix access of NULL pointer
commit 46a51c80216cb891f271ad021f59009f34677499 upstream.
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().
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>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/staging')
| -rw-r--r-- | drivers/staging/zram/zram_sysfs.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/staging/zram/zram_sysfs.c b/drivers/staging/zram/zram_sysfs.c index 1fae1e9..3be52ec 100644 --- a/drivers/staging/zram/zram_sysfs.c +++ b/drivers/staging/zram/zram_sysfs.c @@ -95,6 +95,9 @@ 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; @@ -107,8 +110,7 @@ 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); down_write(&zram->init_lock); if (zram->init_done) |