2024-03-29 01:31:24

by Li Nan

Subject: [PATCH] block: fix overflow in blk_ioctl_discard()

From: Li Nan <[email protected]>

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 <[email protected]>
---
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

2024-04-02 12:32:58

by Christoph Hellwig

Subject: Re: [PATCH] block: fix overflow in blk_ioctl_discard()

On Fri, Mar 29, 2024 at 09:23:19AM +0800, [email protected] wrote:
> From: Li Nan <[email protected]>
>
> 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.

Looks good:

Reviewed-by: Christoph Hellwig <[email protected]>

Can you wire up a testcase in blktests for this condition?

2024-04-02 13:45:15

by Jens Axboe

Subject: Re: [PATCH] block: fix overflow in blk_ioctl_discard()

On Fri, 29 Mar 2024 09:23:19 +0800, [email protected] wrote:
> 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.
>
>

Applied, thanks!

[1/1] block: fix overflow in blk_ioctl_discard()
commit: 22d24a544b0d49bbcbd61c8c0eaf77d3c9297155

Best regards,
--
Jens Axboe

2024-04-03 01:28:52

by Li Nan

Subject: Re: [PATCH] block: fix overflow in blk_ioctl_discard()

在 2024/4/2 20:32, Christoph Hellwig 写道:
> On Fri, Mar 29, 2024 at 09:23:19AM +0800, [email protected] wrote:
>> From: Li Nan <[email protected]>
>>
>> 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.
>
> Looks good:
>
> Reviewed-by: Christoph Hellwig <[email protected]>
>
> Can you wire up a testcase in blktests for this condition?
>

It's my pleasure, I will add testcase later.

>
> .

--
Thanks,
Nan