Commit 5f521494 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: reject unknown mount options early 



[BUG]
The following script would allow invalid mount options to be specified
(although such invalid options would just be ignored):

  # mkfs.btrfs -f $dev
  # mount $dev $mnt1		<<< Successful mount expected
  # mount $dev $mnt2 -o junk	<<< Failed mount expected
  # echo $?
  0

[CAUSE]
For the 2nd mount, since the fs is already mounted, we won't go through
open_ctree() thus no btrfs_parse_options(), but only through
btrfs_parse_subvol_options().

However we do not treat unrecognized options from valid but irrelevant
options, thus those invalid options would just be ignored by
btrfs_parse_subvol_options().

[FIX]
Add the handling for Opt_err to handle invalid options and error out,
while still ignore other valid options inside btrfs_parse_subvol_options().

Reported-by: default avatarAnand Jain <anand.jain@oracle.com>
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 9147b9de

fs/btrfs/super.c

+4 −0
Original line number Diff line number Diff line
@@ -954,6 +954,10 @@ static int btrfs_parse_subvol_options(const char *options, char **subvol_name, 


			*subvol_objectid = subvolid;

			break;

		case Opt_err:

			btrfs_err(NULL, "unrecognized mount option '%s'", p);

			error = -EINVAL;

			goto out;

		default:

			break;

		}