Fix NULL pointer dereference in bl_free_device().

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 setting bdev in struct pnfs_block_dev only if we didn't
get an error from blkdev_get_by_*().

Signed-off-by: Artem Savkov <asavkov@redhat.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Artem Savkov 2016-07-21 13:32:04 +02:00 committed by Trond Myklebust
parent c77efc1e78
commit 297fae4d0b
1 changed files with 13 additions and 9 deletions

View File

@ -235,18 +235,20 @@ bl_parse_simple(struct nfs_server *server, struct pnfs_block_dev *d,
struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
{
struct pnfs_block_volume *v = &volumes[idx];
struct block_device *bdev;
dev_t dev;
dev = bl_resolve_deviceid(server, v, gfp_mask);
if (!dev)
return -EIO;
d->bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_WRITE, NULL);
if (IS_ERR(d->bdev)) {
bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_WRITE, NULL);
if (IS_ERR(bdev)) {
printk(KERN_WARNING "pNFS: failed to open device %d:%d (%ld)\n",
MAJOR(dev), MINOR(dev), PTR_ERR(d->bdev));
return PTR_ERR(d->bdev);
MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
return PTR_ERR(bdev);
}
d->bdev = bdev;
d->len = i_size_read(d->bdev->bd_inode);
@ -350,17 +352,19 @@ bl_parse_scsi(struct nfs_server *server, struct pnfs_block_dev *d,
struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
{
struct pnfs_block_volume *v = &volumes[idx];
struct block_device *bdev;
const struct pr_ops *ops;
int error;
if (!bl_validate_designator(v))
return -EINVAL;
d->bdev = bl_open_dm_mpath_udev_path(v);
if (IS_ERR(d->bdev))
d->bdev = bl_open_udev_path(v);
if (IS_ERR(d->bdev))
return PTR_ERR(d->bdev);
bdev = bl_open_dm_mpath_udev_path(v);
if (IS_ERR(bdev))
bdev = bl_open_udev_path(v);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
d->bdev = bdev;
d->len = i_size_read(d->bdev->bd_inode);
d->map = bl_map_simple;