From: Li Nan <linan122@xxxxxxxxxx>
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@xxxxxxxxxx>
---
block/ioctl.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/block/ioctl.c b/block/ioctl.c
index 0c76137adcaa..a9028a2c2db5 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -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);
--
2.39.2
