From: Baokun Li
mainline inclusion
from mainline-5.14
commit fad7cd3310db3099f95dd34312c77740fbc455e5
category: bugfix
issue: #I4NRS5
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
Signed-off-by: Yu Changchun
-------------------------------------------------
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
Signed-off-by: Baokun Li
Reviewed-by: Josef Bacik
Link: https://lore.kernel.org/r/20210804021212.990223-1-libaokun1@huawei.com
[axboe: dropped unlikely()]
Signed-off-by: Jens Axboe
Conflicts:
drivers/block/nbd.c
Signed-off-by: Baokun Li
Reviewed-by: Hou Tao
Signed-off-by: Chen Jun
Signed-off-by: Zheng Zengkai
Signed-off-by: Yu Changchun
---
drivers/block/nbd.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index f7f1d9dbdc80..f4b0637bb155 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -1385,6 +1385,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
unsigned int cmd, unsigned long arg)
{
struct nbd_config *config = nbd->config;
+ loff_t bytesize;
switch (cmd) {
case NBD_DISCONNECT:
@@ -1407,6 +1408,8 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
div_s64(arg, config->blksize));
return 0;
case NBD_SET_SIZE_BLOCKS:
+ if (check_mul_overflow((loff_t)arg, config->blksize, &bytesize))
+ return -EINVAL;
nbd_size_set(nbd, config->blksize, arg);
return 0;
case NBD_SET_TIMEOUT:
--
2.25.1
