Commit 4f489fe6 authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

mm/damon/sysfs-schemes: free old damon_sysfs_scheme_filter->memcg_path on write 

memcg_path_store() assigns a newly allocated memory buffer to
filter->memcg_path, without deallocating the previously allocated and
assigned memory buffer.  As a result, users can leak kernel memory by
continuously writing a data to memcg_path DAMOS sysfs file.  Fix the leak
by deallocating the previously set memory buffer.

Link: https://lkml.kernel.org/r/20250619183608.6647-2-sj@kernel.org


Fixes: 7ee161f1 ("mm/damon/sysfs-schemes: implement filter directory")
Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>		[6.3.x]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent f5769359

mm/damon/sysfs-schemes.c

+1 −0
Original line number Diff line number Diff line
@@ -472,6 +472,7 @@ static ssize_t memcg_path_store(struct kobject *kobj, 
		return -ENOMEM;



	strscpy(path, buf, count + 1);

	kfree(filter->memcg_path);

	filter->memcg_path = path;

	return count;

}