diff options
| author | Jens Axboe <axboe@kernel.dk> | 2018-09-04 11:52:34 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-09-04 11:54:58 -0600 |
| commit | bc811f05d77f47059c197a98b6ad242eb03999cb (patch) | |
| tree | e96cabff009625665432d1b98fba898eabaa89ba | |
| parent | 3111885015b458c97b4cf272e2a87f1d6f0ed06a (diff) | |
nbd: don't allow invalid blocksize settings
syzbot reports a divide-by-zero off the NBD_SET_BLKSIZE ioctl.
We need proper validation of the input here. Not just if it's
zero, but also if the value is a power-of-2 and in a valid
range. Add that.
Cc: stable@vger.kernel.org
Reported-by: syzbot <syzbot+25dbecbec1e62c6b0dd4@syzkaller.appspotmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | drivers/block/nbd.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 3863c00372bb..14a51254c3db 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1239,6 +1239,9 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, case NBD_SET_SOCK: return nbd_add_socket(nbd, arg, false); case NBD_SET_BLKSIZE: + if (!arg || !is_power_of_2(arg) || arg < 512 || + arg > PAGE_SIZE) + return -EINVAL; nbd_size_set(nbd, arg, div_s64(config->bytesize, arg)); return 0; |