4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Qu Wenruo <wqu@xxxxxxxx>
commit 5f521494cc73520ffac18ede0758883b9aedd018 upstream.
[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: Anand Jain <anand.jain@xxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx # 4.14+
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/super.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -991,6 +991,10 @@ static int btrfs_parse_subvol_options(co
case Opt_subvolrootid:
pr_warn("BTRFS: 'subvolrootid' mount option is deprecated and has no effect\n");
break;
+ case Opt_err:
+ btrfs_err(NULL, "unrecognized mount option '%s'", p);
+ error = -EINVAL;
+ goto out;
default:
break;
}
