================================================================== BUG: KASAN: slab-use-after-free in crc64_be_generic lib/crc/crc64-main.c:47 [inline] BUG: KASAN: slab-use-after-free in crc64_be+0xb8/0xe8 lib/crc/crc64-main.c:68 Read of size 1 at addr ffff0000e2220000 by task syz.0.35/4990 CPU: 1 UID: 0 PID: 4990 Comm: syz.0.35 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xb0/0x238 mm/kasan/report.c:378 print_report+0x68/0x84 mm/kasan/report.c:482 kasan_report+0x8c/0xc4 mm/kasan/report.c:595 __asan_report_load1_noabort+0x20/0x2c mm/kasan/report_generic.c:378 crc64_be_generic lib/crc/crc64-main.c:47 [inline] crc64_be+0xb8/0xe8 lib/crc/crc64-main.c:68 bch_crc64 drivers/md/bcache/util.h:529 [inline] read_super drivers/md/bcache/super.c:208 [inline] register_bcache+0x9a4/0x13d8 drivers/md/bcache/super.c:2601 kobj_attr_store+0x6c/0x90 lib/kobject.c:840 sysfs_kf_write+0xe0/0x108 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x260/0x3b8 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x51c/0xa0c fs/read_write.c:687 ksys_write+0x12c/0x228 fs/read_write.c:739 __do_sys_write fs/read_write.c:750 [inline] __se_sys_write fs/read_write.c:747 [inline] __arm64_sys_write+0x84/0x98 fs/read_write.c:747 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:738 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:757 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590 Allocated by task 4764: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:570 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x70/0x88 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] kmem_cache_alloc_noprof+0x268/0x5d8 mm/slub.c:4931 __kernfs_new_node+0xf0/0x7d8 fs/kernfs/dir.c:665 kernfs_new_node+0xe8/0x130 fs/kernfs/dir.c:751 __kernfs_create_file+0x60/0x2e0 fs/kernfs/file.c:1050 sysfs_add_file_mode_ns+0x1e8/0x2a4 fs/sysfs/file.c:316 create_files fs/sysfs/group.c:82 [inline] internal_create_group+0x550/0xb30 fs/sysfs/group.c:189 internal_create_groups+0x64/0x138 fs/sysfs/group.c:229 sysfs_create_groups+0x2c/0x3c fs/sysfs/group.c:255 device_add_groups drivers/base/core.c:2907 [inline] device_add_attrs+0xdc/0x4e4 drivers/base/core.c:2971 device_add+0x420/0x9e0 drivers/base/core.c:3711 netdev_register_kobject+0x168/0x2f4 net/core/net-sysfs.c:2337 register_netdevice+0xd74/0x14b8 net/core/dev.c:11446 register_netdev+0x4c/0x68 net/core/dev.c:11562 vti6_init_net+0x224/0x36c net/ipv6/ip6_vti.c:1173 ops_init+0x2cc/0x528 net/core/net_namespace.c:137 setup_net+0x118/0x2fc net/core/net_namespace.c:446 copy_net_ns+0x458/0x66c net/core/net_namespace.c:579 create_new_namespaces+0x304/0x50c kernel/nsproxy.c:132 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:234 ksys_unshare+0x3d4/0x6d8 kernel/fork.c:3269 __do_sys_unshare kernel/fork.c:3343 [inline] __se_sys_unshare kernel/fork.c:3341 [inline] __arm64_sys_unshare+0x40/0x54 kernel/fork.c:3341 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:738 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:757 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590 Freed by task 14: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x74/0xa4 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2677 [inline] slab_free mm/slub.c:6377 [inline] kmem_cache_free+0x184/0x6b8 mm/slub.c:6504 kernfs_free_rcu+0xd4/0xe8 fs/kernfs/dir.c:576 rcu_do_batch kernel/rcu/tree.c:2645 [inline] rcu_core+0x598/0xf04 kernel/rcu/tree.c:2897 rcu_core_si+0x10/0x1c kernel/rcu/tree.c:2914 handle_softirqs+0x2ec/0xd98 kernel/softirq.c:622 run_ksoftirqd+0x70/0xbc kernel/softirq.c:1076 smpboot_thread_fn+0x4e4/0x97c kernel/smpboot.c:160 kthread+0x304/0x3d4 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:838 Last potentially related work creation: kasan_save_stack+0x40/0x6c mm/kasan/common.c:57 kasan_record_aux_stack+0xb0/0xc8 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3159 [inline] call_rcu+0x104/0x75c kernel/rcu/tree.c:3279 kernfs_put+0x314/0x620 fs/kernfs/dir.c:618 kernfs_remove_by_name_ns+0x78/0xd0 fs/kernfs/dir.c:1798 kernfs_remove_by_name include/linux/kernfs.h:644 [inline] remove_files+0x90/0x184 fs/sysfs/group.c:28 sysfs_remove_group+0x98/0x160 fs/sysfs/group.c:328 sysfs_remove_groups+0x5c/0xb4 fs/sysfs/group.c:352 device_remove_groups drivers/base/core.c:2914 [inline] device_remove_attrs+0x1e0/0x238 drivers/base/core.c:3050 device_del+0x3e4/0x71c drivers/base/core.c:3960 netdev_unregister_kobject+0x2a8/0x39c net/core/net-sysfs.c:2308 unregister_netdevice_many_notify+0x1234/0x1758 net/core/dev.c:12479 unregister_netdevice_many+0x28/0x38 net/core/dev.c:12507 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x32c/0x81c net/core/net_namespace.c:248 cleanup_net+0x474/0x6c4 net/core/net_namespace.c:702 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0x788/0x10b8 kernel/workqueue.c:3405 worker_thread+0x798/0xbd0 kernel/workqueue.c:3486 kthread+0x304/0x3d4 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:838 The buggy address belongs to the object at ffff0000e2220000 which belongs to the cache kernfs_node_cache of size 176 The buggy address is located 0 bytes inside of freed 176-byte region [ffff0000e2220000, ffff0000e22200b0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x122220 flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000000 ffff0000c1869140 dead000000000122 0000000000000000 raw: 0000000000000000 0000000800110011 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000e221ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000e221ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000e2220000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000e2220080: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb ffff0000e2220100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== bcache: register_bcache() error : Bad checksum