[PATCH 5.15 050/148] mm/slub: fix to return errno if kmalloc() fails

Greg Kroah-Hartman
2022-09-26T11:20:08Z

From: Chao Yu <chao.yu@oppo.com>

commit 7e9c323c52b379d261a72dc7bd38120a761a93cd upstream.

In create_unique_id(), kmalloc(, GFP_KERNEL) can fail due to
out-of-memory, if it fails, return errno correctly rather than
triggering panic via BUG_ON();

kernel BUG at mm/slub.c:5893!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP

Call trace:
sysfs_slab_add+0x258/0x260 mm/slub.c:5973
__kmem_cache_create+0x60/0x118 mm/slub.c:4899
create_cache mm/slab_common.c:229 [inline]
kmem_cache_create_usercopy+0x19c/0x31c mm/slab_common.c:335
kmem_cache_create+0x1c/0x28 mm/slab_common.c:390
f2fs_kmem_cache_create fs/f2fs/f2fs.h:2766 [inline]
f2fs_init_xattr_caches+0x78/0xb4 fs/f2fs/xattr.c:808
f2fs_fill_super+0x1050/0x1e0c fs/f2fs/super.c:4149
mount_bdev+0x1b8/0x210 fs/super.c:1400
f2fs_mount+0x44/0x58 fs/f2fs/super.c:4512
legacy_get_tree+0x30/0x74 fs/fs_context.c:610
vfs_get_tree+0x40/0x140 fs/super.c:1530
do_new_mount+0x1dc/0x4e4 fs/namespace.c:3040
path_mount+0x358/0x914 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__arm64_sys_mount+0x2f8/0x408 fs/namespace.c:3568

Cc: <stable@kernel.org>
Fixes: 81819f0fc8285 ("SLUB core")
Reported-by: syzbot+81684812ea68216e08c5@syzkaller.appspotmail.com
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Chao Yu <chao.yu@oppo.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
mm/slub.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5869,7 +5869,8 @@ static char *create_unique_id(struct kme
char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
char *p = name;

- BUG_ON(!name);
+ if (!name)
+ return ERR_PTR(-ENOMEM);

*p++ = ':';
/*
@@ -5927,6 +5928,8 @@ static int sysfs_slab_add(struct kmem_ca
* for the symlinks.
*/
name = create_unique_id(s);
+ if (IS_ERR(name))
+ return PTR_ERR(name);
}

s->kobj.kset = kset;