From: Chao Yu <chao.yu@xxxxxxxx> 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@xxxxxxxxxx> Reported-by: syzbot+81684812ea68216e08c5@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Chao Yu <chao.yu@xxxxxxxx> --- mm/slub.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/slub.c b/mm/slub.c index 862dbd9af4f5..e6f3727b9ad2 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5890,7 +5890,8 @@ static char *create_unique_id(struct kmem_cache *s) char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL); char *p = name; - BUG_ON(!name); + if (!name) + return ERR_PTR(-ENOMEM); *p++ = ':'; /* @@ -5948,6 +5949,8 @@ static int sysfs_slab_add(struct kmem_cache *s) * for the symlinks. */ name = create_unique_id(s); + if (IS_ERR(name)) + return PTR_ERR(name); } s->kobj.kset = kset; -- 2.25.1
