Re: [RFC PATCH v2 1/8] mm/damon/sysfs-schemes: read sysfs_filter->addr_range only once

[sashiko-bot@kernel.org]

> DAMON sysfs interface reads the user-provided address range arguments
> for addr type DAMOS filter twice.  Once for validation, and once again
> for assignments to the variable that will be passed to the core
> layer. If the user updates the argument in parallel, an invalid address
> range could be passed to the core layer.  Avoid it by doing the
> assignments first, and then validating the assigned variables before
> passing those to the core layer.
> 
> User impact of the bug should be trivial.  From the core layer's
> perspective, the invalid address range is not really invalid.  It just
> works as having a weird address range.  No critical issues such as a
> crash or a leak could happen.  And sane users ain't do such parallel
> arguments update anyway.  If they do, such racy behavior is arguably
> somewhat expected and deserved.  That said, there is no reason to keep
> such races.
> 
> Fixes: 2f1abcfccd86 ("mm/damon/sysfs-schemes: support address range type DAMOS filter")
> Cc: <stable@vger.kernel.org> # 6.6.x
> Signed-off-by: SJ Park <sj@kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260913171706.103052-1-sj@kernel.org?part=1