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| author | Johannes Thumshirn <jthumshirn@suse.de> | 2019-02-18 13:28:37 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-23 22:11:22 +0300 |
| commit | 88e610ae4c3af07d964ba792313c1ac9d50ec7b6 (patch) | |
| tree | c3c1d1f6599b5ab603930ed8cf21feec378cedb6 | |
| parent | 9c58f2ada4fab31f5bf508185ee8b0e4e83cdcd1 (diff) | |
| download | linux-88e610ae4c3af07d964ba792313c1ac9d50ec7b6.tar.xz | |
btrfs: ensure that a DUP or RAID1 block group has exactly two stripes
commit 349ae63f40638a28c6fce52e8447c2d14b84cc0c upstream.
We recently had a customer issue with a corrupted filesystem. When
trying to mount this image btrfs panicked with a division by zero in
calc_stripe_length().
The corrupt chunk had a 'num_stripes' value of 1. calc_stripe_length()
takes this value and divides it by the number of copies the RAID profile
is expected to have to calculate the amount of data stripes. As a DUP
profile is expected to have 2 copies this division resulted in 1/2 = 0.
Later then the 'data_stripes' variable is used as a divisor in the
stripe length calculation which results in a division by 0 and thus a
kernel panic.
When encountering a filesystem with a DUP block group and a
'num_stripes' value unequal to 2, refuse mounting as the image is
corrupted and will lead to unexpected behaviour.
Code inspection showed a RAID1 block group has the same issues.
Fixes: e06cd3dd7cea ("Btrfs: add validadtion checks for chunk loading")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/btrfs/volumes.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 15561926ab32..48523bcabae9 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6782,10 +6782,10 @@ static int btrfs_check_chunk_valid(struct btrfs_fs_info *fs_info, } if ((type & BTRFS_BLOCK_GROUP_RAID10 && sub_stripes != 2) || - (type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes < 1) || + (type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes != 2) || (type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) || (type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes < 3) || - (type & BTRFS_BLOCK_GROUP_DUP && num_stripes > 2) || + (type & BTRFS_BLOCK_GROUP_DUP && num_stripes != 2) || ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 && num_stripes != 1)) { btrfs_err(fs_info, |