From 7fe000eb32904758a85e62f6ea9483f89d5dabfc Mon Sep 17 00:00:00 2001 From: Josh Law Date: Sat, 21 Mar 2026 10:54:24 -0700 Subject: 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: f0c5118ebb0e ("mm/damon/sysfs: catch commit test ctx alloc failure") Signed-off-by: Josh Law Reviewed-by: SeongJae Park Signed-off-by: SeongJae Park Cc: [6.18+] Signed-off-by: Andrew Morton --- mm/damon/sysfs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c index 576d1ddd736b..b573b9d60784 100644 --- a/mm/damon/sysfs.c +++ b/mm/damon/sysfs.c @@ -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; -- cgit v1.2.3