If user specify a large enough value of NBD blocks option, it may trigger
signed integer overflow which may lead to nbd->config->bytesize becomes a
large or small value, zero in particular.
UBSAN: Undefined behaviour in drivers/block/nbd.c:325:31
signed integer overflow:
1024 * 4611686155866341414 cannot be represented in type 'long long int'
[...]
Call trace:
[...]
handle_overflow+0x188/0x1dc lib/ubsan.c:192
__ubsan_handle_mul_overflow+0x34/0x44 lib/ubsan.c:213
nbd_size_set drivers/block/nbd.c:325 [inline]
__nbd_ioctl drivers/block/nbd.c:1342 [inline]
nbd_ioctl+0x998/0xa10 drivers/block/nbd.c:1395
__blkdev_driver_ioctl block/ioctl.c:311 [inline]
[...]
Although it is not a big deal, still silence the UBSAN by limit
the input value.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20210804021212.990223-1-libaokun1@huawei.com
[axboe: dropped unlikely()]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
fad7cd3310