[PATCH 03/11] bus: fix possible memory leak in bus_register()

Yang Yingliang
2022-10-21T02:23:18Z

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

unreferenced object 0xffff888103bddb68 (size 8):
comm "systemd-udevd", pid 341, jiffies 4294903262 (age 42.212s)
hex dump (first 8 bytes):
65 64 61 63 00 00 00 00 edac....
backtrace:
[<000000009e31d566>] __kmalloc_track_caller+0x1ae/0x320
[<00000000e4cfd8de>] kstrdup+0x3a/0x70
[<000000003d0ec369>] kstrdup_const+0x68/0x80
[<000000008e5c3b20>] kvasprintf_const+0x10b/0x190
[<00000000b9a945aa>] kobject_set_name_vargs+0x56/0x150
[<000000000df9278c>] kobject_set_name+0xab/0xe0
[<00000000f51dc49f>] bus_register+0x132/0x350
[<000000007d91c2e5>] subsys_register+0x23/0x220

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
drivers/base/bus.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 7ca47e5b3c1f..301b5330f9d8 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -804,8 +804,10 @@ int bus_register(struct bus_type *bus)
priv->drivers_autoprobe = 1;

retval = kset_register(&priv->subsys);
- if (retval)
+ if (retval) {
+ kset_put(&priv->subsys);
goto out;
+ }

retval = bus_create_file(bus, &bus_attr_uevent);
if (retval)
--
2.25.1