Re: [PATCH v2] ext4: fix off by one issue in alloc_flex_gd()

From: Eric Sandeen
Date: Fri Sep 27 2024 - 10:15:28 EST


On 9/27/24 8:33 AM, libaokun@xxxxxxxxxxxxxxx wrote:
> From: Baokun Li <libaokun1@xxxxxxxxxx>
>

...

> Delete the problematic plus 1 to fix the issue, and add a WARN_ON_ONCE()
> to prevent the issue from happening again.
>
> Reported-by: Wesley Hershberger <wesley.hershberger@xxxxxxxxxxxxx>
> Closes: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2081231
> Reported-by: Stéphane Graber <stgraber@xxxxxxxxxxxx>
> Closes: https://lore.kernel.org/all/20240925143325.518508-1-aleksandr.mikhalitsyn@xxxxxxxxxxxxx/
> Tested-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@xxxxxxxxxxxxx>
> Tested-by: Eric Sandeen <sandeen@xxxxxxxxxx>

The patch has changed a little since I tested, but it still passes my testcase
(as expected, no WARN ON etc) so looks good from that POV, thanks!
-Eric