3.2.54-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Rashika Kheria <rashika.kheria@xxxxxxxxx> 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@xxxxxxxxxx> Signed-off-by: Rashika Kheria <rashika.kheria@xxxxxxxxx> Acked-by: Minchan Kim <minchan@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/staging/zram/zram_sysfs.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- 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 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 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) -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html