[PATCH 6.1 108/236] block: fix overflow in blk_ioctl_discard()

Greg Kroah-Hartman
2024-05-14T11:32:33Z

From: Li Nan <linan122@huawei.com>

[ Upstream commit 22d24a544b0d49bbcbd61c8c0eaf77d3c9297155 ]

There is no check for overflow of 'start + len' in blk_ioctl_discard().
Hung task occurs if submit an discard ioctl with the following param:
start = 0x80000000000ff000, len = 0x8000000000fff000;
Add the overflow validation now.

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240329012319.2034550-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
block/ioctl.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/block/ioctl.c b/block/ioctl.c
index 47567ba1185a6..99b8e2e448729 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -89,7 +89,7 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
unsigned long arg)
{
uint64_t range[2];
- uint64_t start, len;
+ uint64_t start, len, end;
struct inode *inode = bdev->bd_inode;
int err;

@@ -110,7 +110,8 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
if (len & 511)
return -EINVAL;

- if (start + len > bdev_nr_bytes(bdev))
+ if (check_add_overflow(start, len, &end) ||
+ end > bdev_nr_bytes(bdev))
return -EINVAL;

filemap_invalidate_lock(inode->i_mapping);
--
2.43.0