3.5.7.29 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Rashika Kheria <[email protected]> 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 <[email protected]> Signed-off-by: Rashika Kheria <[email protected]> Acked-by: Minchan Kim <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> [ luis: backported to 3.5: - adjusted filename: zram_drv.c -> zram_sysfs.c ] Signed-off-by: Luis Henriques <[email protected]> --- drivers/staging/zram/zram_sysfs.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/staging/zram/zram_sysfs.c b/drivers/staging/zram/zram_sysfs.c index dbe8907..01f9a79 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) -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
