2023-11-06 23:34:32

by SeongJae Park

Subject: [PATCH 3/3] mm/damon/sysfs-schemes: handle tried region directory allocation failure

DAMON sysfs interface's before_damos_apply callback
(damon_sysfs_before_damos_apply()), which creates the DAMOS tried
regions for each DAMOS action applied region, is not handling the
allocation failure for the sysfs directory data. As a result, NULL
pointer derefeence is possible. Fix it by handling the case.

Fixes: f1d13cacabe1 ("mm/damon/sysfs: implement DAMOS tried regions update command")
Cc: <[email protected]> # 6.2.x
Signed-off-by: SeongJae Park <[email protected]>
---
mm/damon/sysfs-schemes.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index 7413cb35c5a9..be667236b8e6 100644
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -1826,6 +1826,8 @@ static int damon_sysfs_before_damos_apply(struct damon_ctx *ctx,
return 0;

region = damon_sysfs_scheme_region_alloc(r);
+ if (!region)
+ return 0;
list_add_tail(&region->list, &sysfs_regions->regions_list);
sysfs_regions->nr_regions++;
if (kobject_init_and_add(&region->kobj,
--
2.34.1