==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:72 [inline]
BUG: KASAN: null-ptr-deref in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
BUG: KASAN: null-ptr-deref in dm_kcopyd_client_destroy+0xa0/0x424 drivers/md/dm-kcopyd.c:972
Read of size 4 at addr 0000000000000174 by task syz.0.67/4819

CPU: 0 PID: 4819 Comm: syz.0.67 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/23/2026
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 print_report+0x40/0x68 mm/kasan/report.c:423
 kasan_report+0xa8/0xfc mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x258/0x290 mm/kasan/generic.c:189
 __kasan_check_read+0x2c/0x3c mm/kasan/shadow.c:31
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
 dm_kcopyd_client_destroy+0xa0/0x424 drivers/md/dm-kcopyd.c:972
 __destroy+0x15c/0x2cc drivers/md/dm-cache-target.c:1955
 cache_create drivers/md/dm-cache-target.c:2592 [inline]
 cache_ctr+0x115c/0x2330 drivers/md/dm-cache-target.c:2637
 dm_table_add_target+0x4a4/0xb04 drivers/md/dm-table.c:733
 populate_table drivers/md/dm-ioctl.c:1440 [inline]
 table_load+0x26c/0x690 drivers/md/dm-ioctl.c:1482
 ctl_ioctl drivers/md/dm-ioctl.c:2055 [inline]
 dm_ctl_ioctl+0xaac/0xf1c drivers/md/dm-ioctl.c:2077
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
==================================================================
Unable to handle kernel paging request at virtual address dfff80000000002e
KASAN: null-ptr-deref in range [0x0000000000000170-0x0000000000000177]
Mem abort info:
  ESR = 0x0000000096000006
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000006
  CM = 0, WnR = 0
[dfff80000000002e] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4819 Comm: syz.0.67 Tainted: G    B              syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/23/2026
pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : atomic_read include/linux/atomic/atomic-instrumented.h:28 [inline]
pc : dm_kcopyd_client_destroy+0xa4/0x424 drivers/md/dm-kcopyd.c:972
lr : instrument_atomic_read include/linux/instrumented.h:72 [inline]
lr : atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
lr : dm_kcopyd_client_destroy+0xa0/0x424 drivers/md/dm-kcopyd.c:972
sp : ffff800022987600
x29: ffff8000229876a0 x28: ffff700004530f00 x27: 1fffe0001ea5986d
x26: 1fffe0001ea5983d x25: 000000000000002e x24: 0000000000000174
x23: dfff800000000000 x22: ffff700004530ec0 x21: ffff800022987600
x20: fffffffffffffff4 x19: fffffffffffffff4 x18: 1fffe00033c1877e
x17: 0000000000000000
 x16: ffff800008043a58
 x15: 0000000000000002
x14: 0000000000000001
 x13: 1ffff00003203f6c
 x12: 0000000000080000
x11: 000000000007ffff x10: ffff80002cf28000 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800022986fd8 x4 : ffff800016504f40 x3 : ffff800008195a30
x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 atomic_read include/linux/atomic/atomic-instrumented.h:28 [inline]
 dm_kcopyd_client_destroy+0xa4/0x424 drivers/md/dm-kcopyd.c:972
 __destroy+0x15c/0x2cc drivers/md/dm-cache-target.c:1955
 cache_create drivers/md/dm-cache-target.c:2592 [inline]
 cache_ctr+0x115c/0x2330 drivers/md/dm-cache-target.c:2637
 dm_table_add_target+0x4a4/0xb04 drivers/md/dm-table.c:733
 populate_table drivers/md/dm-ioctl.c:1440 [inline]
 table_load+0x26c/0x690 drivers/md/dm-ioctl.c:1482
 ctl_ioctl drivers/md/dm-ioctl.c:2055 [inline]
 dm_ctl_ioctl+0xaac/0xf1c drivers/md/dm-ioctl.c:2077
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: 52800081 91060278 9674e6b6 d343ff19 (38f76b28) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	52800081 	mov	w1, #0x4                   	// #4
   4:	91060278 	add	x24, x19, #0x180
   8:	9674e6b6 	bl	0xfffffffff9d39ae0
   c:	d343ff19 	lsr	x25, x24, #3
* 10:	38f76b28 	ldrsb	w8, [x25, x23] <-- trapping instruction