[PATCH 08/11] erofs: fix possible memory leak in erofs_init_sysfs()

Yang Yingliang
2022-10-21T02:24:12Z

Inject fault while loading module, kset_register() may fail,
if it fails, but the refcount of kobject is not decreased to
0, the name allocated in kobject_set_name() is leaked. Fix
this by calling kset_put(), so that name can be freed in
callback function kobject_cleanup().

unreferenced object 0xffff888101d228c0 (size 8):
comm "modprobe", pid 276, jiffies 4294722700 (age 13.151s)
hex dump (first 8 bytes):
65 72 6f 66 73 00 ff ff erofs...
backtrace:
[<00000000e2a9a4a6>] __kmalloc_node_track_caller+0x44/0x1b0
[<00000000b8ce02de>] kstrdup+0x3a/0x70
[<000000004a0e01d2>] kstrdup_const+0x63/0x80
[<00000000051b6cda>] kvasprintf_const+0x149/0x180
[<000000004dc51dad>] kobject_set_name_vargs+0x56/0x150
[<00000000b30f0bad>] kobject_set_name+0xab/0xe0

Fixes: 168e9a76200c ("erofs: add sysfs interface")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
fs/erofs/sysfs.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c
index 783bb7b21b51..653b35001bc5 100644
--- a/fs/erofs/sysfs.c
+++ b/fs/erofs/sysfs.c
@@ -254,8 +254,10 @@ int __init erofs_init_sysfs(void)
kobject_set_name(&erofs_root.kobj, "erofs");
erofs_root.kobj.parent = fs_kobj;
ret = kset_register(&erofs_root);
- if (ret)
+ if (ret) {
+ kset_put(&erofs_root);
goto root_err;
+ }

ret = kobject_init_and_add(&erofs_feat, &erofs_feat_ktype,
NULL, "features");
--
2.25.1