Re: [PATCH v7 1/3] Staging: zram: Fix access of NULL pointer
From: Minchan Kim
Date: Tue Oct 29 2013 - 22:36:27 EST
On Wed, Oct 30, 2013 at 04:40:54AM +0530, Rashika Kheria wrote:
> 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@xxxxxxxxxxxxxxx
> Signed-off-by: Rashika Kheria <rashika.kheria@xxxxxxxxx>
> This patch fixes the following issues of the previous revision-
> Better Description
> drivers/staging/zram/zram_drv.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
> diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
> index 2c4ed52..d640a8f 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 -EBUSY;
I don't think EBUSY is right. How about ENOMEM?
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/