diff options
author | Johannes Thumshirn <jthumshirn@suse.de> | 2019-02-18 11:28:37 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-23 14:35:21 +0100 |
commit | 904bc9a1ce0a1037f3c2d09fe2e84de679255bb0 (patch) | |
tree | 4bde1985dd77d418f526dca0c3a7a2bd81f464ee /crypto | |
parent | bc726ae072b256230915ff341cdc93a51259686c (diff) |
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>
Diffstat (limited to 'crypto')
0 files changed, 0 insertions, 0 deletions