From: Eiichi Tsukata Date: Thu, 6 Aug 2020 22:18:48 +0000 (-0700) Subject: xfs: Fix UBSAN null-ptr-deref in xfs_sysfs_init X-Git-Tag: v4.9.234~14 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a7631e087f1e0eac2fa06a54674e8fdea794105c;p=platform%2Fkernel%2Flinux-amlogic.git xfs: Fix UBSAN null-ptr-deref in xfs_sysfs_init [ Upstream commit 96cf2a2c75567ff56195fe3126d497a2e7e4379f ] If xfs_sysfs_init is called with parent_kobj == NULL, UBSAN shows the following warning: 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 Reviewed-by: Darrick J. Wong [darrick: minor whitespace edits] Signed-off-by: Darrick J. Wong Signed-off-by: Sasha Levin --- diff --git a/fs/xfs/xfs_sysfs.h b/fs/xfs/xfs_sysfs.h index d04637181ef2..980c9429abec 100644 --- a/fs/xfs/xfs_sysfs.h +++ b/fs/xfs/xfs_sysfs.h @@ -44,9 +44,11 @@ xfs_sysfs_init( struct xfs_kobj *parent_kobj, const char *name) { + struct kobject *parent; + + 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