Commit 22d24a54 authored Mar 29, 2024 by Li Nan Committed by Jens Axboe Apr 02, 2024

block: fix overflow in blk_ioctl_discard()



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>

parent fbbd5d3a

block/ioctl.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -96,7 +96,7 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_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;

		@@ -117,7 +117,8 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_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);