[PATCH 6.0 0715/1073] vme: Fix error not catched in fake_init()

Greg Kroah-Hartman
2022-12-28T16:25:10Z

From: Chen Zhongjin <chenzhongjin@huawei.com>

[ Upstream commit 7bef797d707f1744f71156b21d41e3b8c946631f ]

In fake_init(), __root_device_register() is possible to fail but it's
ignored, which can cause unregistering vme_root fail when exit.

general protection fault,
probably for non-canonical address 0xdffffc000000008c
KASAN: null-ptr-deref in range [0x0000000000000460-0x0000000000000467]
RIP: 0010:root_device_unregister+0x26/0x60
Call Trace:
<TASK>
__x64_sys_delete_module+0x34f/0x540
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Return error when __root_device_register() fails.

Fixes: 658bcdae9c67 ("vme: Adding Fake VME driver")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Link: https://lore.kernel.org/r/20221205084805.147436-1-chenzhongjin@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/staging/vme_user/vme_fake.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/staging/vme_user/vme_fake.c b/drivers/staging/vme_user/vme_fake.c
index dd646b0c531d..1ee432c223e2 100644
--- a/drivers/staging/vme_user/vme_fake.c
+++ b/drivers/staging/vme_user/vme_fake.c
@@ -1073,6 +1073,8 @@ static int __init fake_init(void)

/* We need a fake parent device */
vme_root = __root_device_register("vme", THIS_MODULE);
+ if (IS_ERR(vme_root))
+ return PTR_ERR(vme_root);

/* If we want to support more than one bridge at some point, we need to
* dynamically allocate this so we get one per device.
--
2.35.1