6.1-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 @@ -1260,6 +1260,10 @@ static int btrfs_parse_subvol_options(co *subvol_objectid = subvolid; break; + case Opt_err: + btrfs_err(NULL, "unrecognized mount option '%s'", p); + error = -EINVAL; + goto out; default: break; }