Unable to handle kernel paging request at virtual address dfff800000000001 KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] 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 [dfff800000000001] address between user and kernel address ranges Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 6904 Comm: syz.1.859 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026 pstate: 824000c5 (Nzcv daIF +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : percpu_ref_kill_and_confirm+0x118/0x150 lib/percpu-refcount.c:391 lr : percpu_ref_kill_and_confirm+0xec/0x150 lib/percpu-refcount.c:389 sp : ffff800020f17770 x29: ffff800020f17770 x28: 000000000000000a x27: 1fffe000201a1803 x26: ffff000100d0c018 x25: ffff000100d0c048 x24: 1fffe000201a1808 x23: dfff800000000000 x22: 0000000000000008 x21: 0000000000000000 x20: 0000000000000000 x19: ffff000100d0c040 x18: 0000000000000000 x17: 0000000000000000 x16: ffff8000082f2858 x15: 000000000004ffff x14: ffff7000041e2ed4 x13: 1ffff000041e2ed4 x12: 0000000000080000 x11: 000000000000083f x10: ffff8000223fb000 x9 : 1fffe000201a1809 x8 : 0000000000000001 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000020 x4 : 0000000000000000 x3 : ffff8000082f2980 x2 : 0000000000000001 x1 : 0000000000000002 x0 : 0000000000000000 Call trace: percpu_ref_kill_and_confirm+0x118/0x150 lib/percpu-refcount.c:391 percpu_ref_kill include/linux/percpu-refcount.h:149 [inline] mddev_suspend+0x1c0/0x4e0 drivers/md/md.c:470 mddev_create_serial_pool+0x210/0x3fc drivers/md/md.c:221 backlog_store+0x2ac/0x3f0 drivers/md/md-bitmap.c:2508 md_attr_store+0x168/0x234 drivers/md/md.c:5626 sysfs_kf_write+0x1f8/0x274 fs/sysfs/file.c:140 kernfs_fop_write_iter+0x390/0x4b4 fs/kernfs/file.c:352 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: 977f1b91 f9400328 91002116 d343fec8 (38776908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 977f1b91 bl 0xfffffffffdfc6e44 4: f9400328 ldr x8, [x25] 8: 91002116 add x22, x8, #0x8 c: d343fec8 lsr x8, x22, #3 * 10: 38776908 ldrb w8, [x8, x23] <-- trapping instruction