Commit 7fe000eb authored by Josh Law's avatar Josh Law Committed by Andrew Morton
Browse files

mm/damon/sysfs: fix param_ctx leak on damon_sysfs_new_test_ctx() failure 

Patch series "mm/damon/sysfs: fix memory leak and NULL dereference
issues", v4.

DAMON_SYSFS can leak memory under allocation failure, and do NULL pointer
dereference when a privileged user make wrong sequences of control.  Fix
those.


This patch (of 3):

When damon_sysfs_new_test_ctx() fails in damon_sysfs_commit_input(),
param_ctx is leaked because the early return skips the cleanup at the out
label.  Destroy param_ctx before returning.

Link: https://lkml.kernel.org/r/20260321175427.86000-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20260321175427.86000-2-sj@kernel.org


Fixes: f0c5118e ("mm/damon/sysfs: catch commit test ctx alloc failure")
Signed-off-by: default avatarJosh Law <objecting@objecting.org>
Reviewed-by: default avatarSeongJae Park <sj@kernel.org>
Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>	[6.18+]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 9e0d0ddf

mm/damon/sysfs.c

+3 −1
Original line number Diff line number Diff line
@@ -1524,8 +1524,10 @@ static int damon_sysfs_commit_input(void *data) 
	if (IS_ERR(param_ctx))

		return PTR_ERR(param_ctx);

	test_ctx = damon_sysfs_new_test_ctx(kdamond->damon_ctx);

	if (!test_ctx)

	if (!test_ctx) {

		damon_destroy_ctx(param_ctx);

		return -ENOMEM;

	}

	err = damon_commit_ctx(test_ctx, param_ctx);

	if (err)

		goto out;