From: Wang Hai wanghai26@huawei.com
[ 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: baf8532a147d ("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 --- drivers/memstick/core/memstick.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/memstick/core/memstick.c b/drivers/memstick/core/memstick.c index 6cfb293396f2..693ee73eb291 100644 --- a/drivers/memstick/core/memstick.c +++ b/drivers/memstick/core/memstick.c @@ -625,13 +625,18 @@ 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;