| Message ID | 1468942744-10646-1-git-send-email-asavkov@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jul 19, 2016 at 05:39:04PM +0200, Artem Savkov wrote: > When bl_parse_deviceid() fails in bl_alloc_deviceid_node() on > blkdev_get_by_*() step we get an pnfs_block_dev struct that is > uninitialized except for bdev field which is set to whatever error > blkdev_get_by_*() returns. bl_free_device() then tries to call > blkdev_put() if bdev is not 0 resulting in a wrong pointer dereference. > > Fixing this by making sure bdev is not an error code in bl_free_device(). > > Signed-off-by: Artem Savkov <asavkov@redhat.com> I guess this is fine to be defensive, but we should probably just ensure ->bdev is NULLed on failure. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c index 118252f..57cb800 100644 --- a/fs/nfs/blocklayout/dev.c +++ b/fs/nfs/blocklayout/dev.c @@ -33,7 +33,7 @@ bl_free_device(struct pnfs_block_dev *dev) pr_err("failed to unregister PR key.\n"); } - if (dev->bdev) + if (!IS_ERR_OR_NULL(dev->bdev)) blkdev_put(dev->bdev, FMODE_READ | FMODE_WRITE); } }
When bl_parse_deviceid() fails in bl_alloc_deviceid_node() on blkdev_get_by_*() step we get an pnfs_block_dev struct that is uninitialized except for bdev field which is set to whatever error blkdev_get_by_*() returns. bl_free_device() then tries to call blkdev_put() if bdev is not 0 resulting in a wrong pointer dereference. Fixing this by making sure bdev is not an error code in bl_free_device(). Signed-off-by: Artem Savkov <asavkov@redhat.com> --- fs/nfs/blocklayout/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)