WARNING in null_report_zones

Status: upstream: reported on 2026/08/30 22:38
Reported-by: syzbot+e3948671cae81953ae02@syzkaller.appspotmail.com
First crash: 21d, last: 21d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in null_report_zones prio:low block -1 syz 6 33d 46d 0/29 upstream: reported syz repro on 2026/08/06 15:27

Sample crash report:
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: CPU: 0 PID: 5226 at kernel/locking/mutex.c:582 __mutex_lock_common+0x1468/0x1f3c kernel/locking/mutex.c:582
Modules linked in:
CPU: 0 PID: 5226 Comm: syz.0.274 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : __mutex_lock_common+0x1468/0x1f3c kernel/locking/mutex.c:582
lr : __mutex_lock_common+0x1468/0x1f3c kernel/locking/mutex.c:582
sp : ffff8000218174e0
x29: ffff800021817630 x28: ffff700004302eb0 x27: 0000000000000000
x26: 0000000000000000 x25: ffff800033955190 x24: 0000000000000000
x23: dfff800000000000 x22: ffff80000c0b7280 x21: ffff8000218175a0
x20: 0000000000000000 x19: ffff800033955240 x18: 1fffe00033e7037e
x17: ffff80001538d000 x16: ffff800008043b30 x15: 0000000040000000
x14: 0000000000000001 x13: 1fffe00033e72a70 x12: 0000000000000000
x11: ff00800008048e14 x10: 0000000040000002 x9 : 7ffaec2a7e676a00
x8 : 7ffaec2a7e676a00 x7 : ffff800011cfc160 x6 : ffff80000825ab48
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : ffff8000218170a0 x1 : 0000000000000000 x0 : ffff80000825abdc
Call trace:
 __mutex_lock_common+0x1468/0x1f3c kernel/locking/mutex.c:582
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 null_lock_zone drivers/block/null_blk/zoned.c:51 [inline]
 null_report_zones+0x28c/0x798 drivers/block/null_blk/zoned.c:232
 blk_revalidate_disk_zones+0x1d4/0x50c block/blk-zoned.c:580
 null_register_zoned_dev+0xd4/0x2c4 drivers/block/null_blk/zoned.c:184
 null_gendisk_register+0x1ac/0x298 drivers/block/null_blk/main.c:1913
 null_add_dev+0xbe0/0x142c drivers/block/null_blk/main.c:2146
 nullb_device_power_store+0x160/0x39c drivers/block/null_blk/main.c:465
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x260/0x338 fs/configfs/file.c:229
 call_write_iter include/linux/fs.h:2271 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x3c8/0x7c8 fs/read_write.c:584
 ksys_write+0x12c/0x228 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
 __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+0x58/0x128 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
irq event stamp: 70119
hardirqs last  enabled at (70119): [<ffff80000825abdc>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1374 [inline]
hardirqs last  enabled at (70119): [<ffff80000825abdc>] finish_lock_switch+0xb0/0x1c8 kernel/sched/core.c:5005
hardirqs last disabled at (70118): [<ffff800011c71430>] __schedule+0x294/0x1a6c kernel/sched/core.c:6461
softirqs last  enabled at (54502): [<ffff8000081ae3b4>] softirq_handle_end kernel/softirq.c:439 [inline]
softirqs last  enabled at (54502): [<ffff8000081ae3b4>] handle_softirqs+0xb1c/0xc90 kernel/softirq.c:624
softirqs last disabled at (54483): [<ffff800008020e6c>] __do_softirq+0x14/0x20 kernel/softirq.c:630
---[ end trace 0000000000000000 ]---
Unable to handle kernel paging request at virtual address fbd529d5a0000006
KASAN: maybe wild-memory-access in range [0xdead4ead00000030-0xdead4ead00000037]
Mem abort info:
  ESR = 0x0000000096000004
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x04: level 0 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000004
  CM = 0, WnR = 0
[fbd529d5a0000006] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 5226 Comm: syz.0.274 Tainted: G        W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : owner_on_cpu include/linux/sched.h:2306 [inline]
pc : mutex_can_spin_on_owner kernel/locking/mutex.c:409 [inline]
pc : mutex_optimistic_spin+0x1f8/0x3f4 kernel/locking/mutex.c:452
lr : instrument_atomic_read include/linux/instrumented.h:72 [inline]
lr : atomic_long_read include/linux/atomic/atomic-instrumented.h:1265 [inline]
lr : __mutex_owner kernel/locking/mutex.c:81 [inline]
lr : mutex_can_spin_on_owner kernel/locking/mutex.c:407 [inline]
lr : mutex_optimistic_spin+0x1d0/0x3f4 kernel/locking/mutex.c:452
sp : ffff800021817490
x29: ffff800021817490 x28: ffff700004302eb0 x27: 0000000000000000
x26: 0000000000000000 x25: ffff800033955190 x24: dead4ead00000034
x23: dfff800000000000 x22: dead4ead00000000 x21: 0000000000000000
x20: 0000000000000000 x19: ffff800033955240 x18: 1fffe00033e7037e
x17: ffff80001538d000 x16: ffff8000082d4c34 x15: 0000000040000000
x14: 0000000000000001 x13: 1ffff0000672aa48 x12: 0000000000000000
x11: 0000000000000000 x10: ffff70000672aa49 x9 : 1ffff0000672aa48
x8 : 1bd5a9d5a0000006 x7 : ffff800011cfc160 x6 : ffff80000c0b7280
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff8000082d4e04
x2 : 0000000000000000 x1 : 0000000000000008 x0 : 0000000000000001
Call trace:
 owner_on_cpu include/linux/sched.h:2306 [inline]
 mutex_can_spin_on_owner kernel/locking/mutex.c:409 [inline]
 mutex_optimistic_spin+0x1f8/0x3f4 kernel/locking/mutex.c:452
 __mutex_lock_common+0x1cc/0x1f3c kernel/locking/mutex.c:607
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 null_lock_zone drivers/block/null_blk/zoned.c:51 [inline]
 null_report_zones+0x28c/0x798 drivers/block/null_blk/zoned.c:232
 blk_revalidate_disk_zones+0x1d4/0x50c block/blk-zoned.c:580
 null_register_zoned_dev+0xd4/0x2c4 drivers/block/null_blk/zoned.c:184
 null_gendisk_register+0x1ac/0x298 drivers/block/null_blk/main.c:1913
 null_add_dev+0xbe0/0x142c drivers/block/null_blk/main.c:2146
 nullb_device_power_store+0x160/0x39c drivers/block/null_blk/main.c:465
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x260/0x338 fs/configfs/file.c:229
 call_write_iter include/linux/fs.h:2271 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x3c8/0x7c8 fs/read_write.c:584
 ksys_write+0x12c/0x228 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
 __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+0x58/0x128 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: f27df116 54000180 9100d2d8 d343ff08 (38f76908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	f27df116 	ands	x22, x8, #0xfffffffffffffff8
   4:	54000180 	b.eq	0x34  // b.none
   8:	9100d2d8 	add	x24, x22, #0x34
   c:	d343ff08 	lsr	x8, x24, #3
* 10:	38f76908 	ldrsb	w8, [x8, x23] <-- trapping instruction

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/30 22:38 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in null_report_zones
* Struck through repros no longer work on HEAD.