• Wang Hai's avatar
    memstick: Fix error cleanup path of memstick_init · 65f1a0d3
    Wang Hai authored
    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: baf8532a ("memstick: initial commit for Sony MemoryStick support")
    Reported-by: default avatarHulk Robot <hulkci@huawei.com>
    Signed-off-by: default avatarWang Hai <wanghai26@huawei.com>
    Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
    65f1a0d3
memstick.c 16.1 KB