==================================================================
BUG: KASAN: use-after-free in crc64_be_generic lib/crc/crc64-main.c:47 [inline]
BUG: KASAN: use-after-free in crc64_be+0xb8/0xe8 lib/crc/crc64-main.c:68
Read of size 1 at addr ffff0000ccc64000 by task syz.5.688/8388

CPU: 0 UID: 0 PID: 8388 Comm: syz.5.688 Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
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

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff0000ccc64000 pfn:0x10cc64
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffdffc3134b08 fffffdffc3e39e08 0000000000000000
raw: ffff0000ccc64000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000ccc63f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000ccc63f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000ccc64000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff0000ccc64080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000ccc64100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
bcache: register_bcache() error : Bad checksum