linux/fs/xfs/xfs_sysfs.h
Eiichi Tsukata 96cf2a2c75 xfs: Fix UBSAN null-ptr-deref in xfs_sysfs_init
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 <devel@etsukata.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: minor whitespace edits]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-08-07 11:50:17 -07:00

55 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2014 Red Hat, Inc.
* All Rights Reserved.
*/
#ifndef __XFS_SYSFS_H__
#define __XFS_SYSFS_H__
extern struct kobj_type xfs_mp_ktype; /* xfs_mount */
extern struct kobj_type xfs_dbg_ktype; /* debug */
extern struct kobj_type xfs_log_ktype; /* xlog */
extern struct kobj_type xfs_stats_ktype; /* stats */
static inline struct xfs_kobj *
to_kobj(struct kobject *kobject)
{
return container_of(kobject, struct xfs_kobj, kobject);
}
static inline void
xfs_sysfs_release(struct kobject *kobject)
{
struct xfs_kobj *kobj = to_kobj(kobject);
complete(&kobj->complete);
}
static inline int
xfs_sysfs_init(
struct xfs_kobj *kobj,
struct kobj_type *ktype,
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, "%s", name);
}
static inline void
xfs_sysfs_del(
struct xfs_kobj *kobj)
{
kobject_del(&kobj->kobject);
kobject_put(&kobj->kobject);
wait_for_completion(&kobj->complete);
}
int xfs_error_sysfs_init(struct xfs_mount *mp);
void xfs_error_sysfs_del(struct xfs_mount *mp);
#endif /* __XFS_SYSFS_H__ */