Hi, On 2022/12/5 20:31, Greg KH wrote:
On Mon, Dec 05, 2022 at 04:48:05PM +0800, Chen Zhongjin wrote: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@xxxxxxxxxx> --- 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);This should be calling root_device_register() as well, not this version of the call.
Of course it should. Have sent another patch for it. Thanks for your time! Chen
thanks, greg k-h
