Messages in this thread | | | Date | Thu, 6 Aug 2020 08:13:31 -0700 | From | "Darrick J. Wong" <> | Subject | Re: [PATCH] xfs: Fix UBSAN null-ptr-deref in xfs_sysfs_init |
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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@etsukata.com> > --- > 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 >
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