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Commit ccb0e7d1 authored by Anand Jain's avatar Anand Jain Committed by David Sterba
Browse files

btrfs: verify subvolid mount parameter 



We aren't verifying the parameter passed to the subvolid mount option,
so we won't report and fail the mount if a junk value is specified for
example, -o subvolid=abc.
This patch verifies the subvolid option with match_u64.

Up to now the memparse function accepts the K/M/G/ suffixes, that are
usually meant for size values and do not make sense for a subvolume it.

Signed-off-by: default avatarAnand Jain <anand.jain@oracle.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 58113753

fs/btrfs/super.c

+9 −12
Original line number Diff line number Diff line
@@ -914,8 +914,8 @@ static int btrfs_parse_subvol_options(const char *options, fmode_t flags, 
{

	substring_t args[MAX_OPT_ARGS];

	char *opts, *orig, *p;

	char *num = NULL;

	int error = 0;

	u64 subvolid;



	if (!options)

		return 0;
@@ -945,18 +945,15 @@ static int btrfs_parse_subvol_options(const char *options, fmode_t flags, 
			}

			break;

		case Opt_subvolid:

			num = match_strdup(&args[0]);

			if (num) {

				*subvol_objectid = memparse(num, NULL);

				kfree(num);

				/* we want the original fs_tree */

				if (!*subvol_objectid)

					*subvol_objectid =

						BTRFS_FS_TREE_OBJECTID;

			} else {

				error = -EINVAL;

			error = match_u64(&args[0], &subvolid);

			if (error)

				goto out;

			}



			/* we want the original fs_tree */

			if (subvolid == 0)

				subvolid = BTRFS_FS_TREE_OBJECTID;



			*subvol_objectid = subvolid;

			break;

		case Opt_subvolrootid:

			pr_warn("BTRFS: 'subvolrootid' mount option is deprecated and has no effect\n");