Thanks, I sent it to linux-xfs ML. I had some trouble with gmail server.
Eiichi
On 2020/08/07 0:13, Darrick J. Wong wrote:
> On Fri, Aug 07, 2020 at 12:05:27AM +0900, Eiichi Tsukata wrote:
>> If xfs_sysfs_init is called with parent_kobj == NULL, UBSAN
>> shows the following warning:
>
> This needs to be sent to the xfs mailing list, per get_maintainers.pl.
>
> --D
>
>> UBSAN: null-ptr-deref in ./fs/xfs/xfs_sysfs.h:37:23
>> member access within null pointer of type 'struct xfs_kobj'
>> Call Trace:
>> dump_stack+0x10e/0x195
>> ubsan_type_mismatch_common+0x241/0x280
>> __ubsan_handle_type_mismatch_v1+0x32/0x40
>> init_xfs_fs+0x12b/0x28f
>> do_one_initcall+0xdd/0x1d0
>> do_initcall_level+0x151/0x1b6
>> do_initcalls+0x50/0x8f
>> do_basic_setup+0x29/0x2b
>> kernel_init_freeable+0x19f/0x20b
>> kernel_init+0x11/0x1e0
>> ret_from_fork+0x22/0x30
>>
>> Fix it by checking parent_kobj before the code accesses its member.
>>
>> Signed-off-by: Eiichi Tsukata <devel@xxxxxxxxxxxx>
>> ---
>> fs/xfs/xfs_sysfs.h | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/xfs/xfs_sysfs.h b/fs/xfs/xfs_sysfs.h
>> index e9f810fc6731..aad67dc4ab5b 100644
>> --- a/fs/xfs/xfs_sysfs.h
>> +++ b/fs/xfs/xfs_sysfs.h
>> @@ -32,9 +32,9 @@ xfs_sysfs_init(
>> struct xfs_kobj *parent_kobj,
>> const char *name)
>> {
>> + struct kobject *parent = parent_kobj ? &parent_kobj->kobject : NULL;
>> init_completion(&kobj->complete);
>> - return kobject_init_and_add(&kobj->kobject, ktype,
>> - &parent_kobj->kobject, "%s", name);
>> + return kobject_init_and_add(&kobj->kobject, ktype, parent, "%s", name);
>> }
>>
>> static inline void
>> --
>> 2.26.2
>>
