memstick: Fix error cleanup path of memstick_init

[ Upstream commit 65f1a0d39c289bb6fc85635528cd36c4b07f560e ]

If bus_register fails. On its error handling path, it has cleaned up
what it has done. There is no need to call bus_unregister again.
Otherwise, if bus_unregister is called, issues such as null-ptr-deref
will arise.

Syzkaller report this:

kobject_add_internal failed for memstick (error: -12 parent: bus)
BUG: KASAN: null-ptr-deref in sysfs_remove_file_ns+0x1b/0x40 fs/sysfs/file.c:467
Read of size 8 at addr 0000000000000078 by task syz-executor.0/4460

Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xa9/0x10e lib/dump_stack.c:113
 __kasan_report+0x171/0x18d mm/kasan/report.c:321
 kasan_report+0xe/0x20 mm/kasan/common.c:614
 sysfs_remove_file_ns+0x1b/0x40 fs/sysfs/file.c:467
 sysfs_remove_file include/linux/sysfs.h:519 [inline]
 bus_remove_file+0x6c/0x90 drivers/base/bus.c:145
 remove_probe_files drivers/base/bus.c:599 [inline]
 bus_unregister+0x6e/0x100 drivers/base/bus.c:916 ? 0xffffffffc1590000
 memstick_init+0x7a/0x1000 [memstick]
 do_one_initcall+0xb9/0x3b5 init/main.c:914
 do_init_module+0xe0/0x330 kernel/module.c:3468
 load_module+0x38eb/0x4270 kernel/module.c:3819
 __do_sys_finit_module+0x162/0x190 kernel/module.c:3909
 do_syscall_64+0x72/0x2a0 arch/x86/entry/common.c:298
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: baf8532a14 ("memstick: initial commit for Sony MemoryStick support")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai26@huawei.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Wang Hai 2019-05-15 22:37:25 +08:00 committed by Greg Kroah-Hartman
parent 0a50a27238
commit 5c0e54839d

View file

@ -629,13 +629,18 @@ static int __init memstick_init(void)
return -ENOMEM;
rc = bus_register(&memstick_bus_type);
if (!rc)
rc = class_register(&memstick_host_class);
if (rc)
goto error_destroy_workqueue;
if (!rc)
return 0;
rc = class_register(&memstick_host_class);
if (rc)
goto error_bus_unregister;
return 0;
error_bus_unregister:
bus_unregister(&memstick_bus_type);
error_destroy_workqueue:
destroy_workqueue(workqueue);
return rc;