------------[ cut here ]------------ WARNING: CPU: 1 PID: 10509 at kernel/kthread.c:83 to_kthread kernel/kthread.c:83 [inline] WARNING: CPU: 1 PID: 10509 at kernel/kthread.c:83 kthread_stop+0x58d/0x610 kernel/kthread.c:617 Modules linked in: CPU: 1 PID: 10509 Comm: syz-executor.5 Not tainted 5.10.56 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 RIP: 0010:to_kthread kernel/kthread.c:83 [inline] RIP: 0010:kthread_stop+0x58d/0x610 kernel/kthread.c:617 Code: 00 4c 89 e7 e8 a4 6a d2 00 e9 76 fc ff ff e8 aa 98 23 00 be 02 00 00 00 4c 89 e7 e8 8d 6a d2 00 e9 33 fb ff ff e8 93 98 23 00 <0f> 0b e9 74 fb ff ff e8 27 ca 4e 00 e9 50 fb ff ff e8 1d ca 4e 00 RSP: 0018:ffff88805e89f998 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff811be930 RDX: ffff888057263280 RSI: ffffffff811bedbd RDI: 0000000000000005 RBP: ffff888056b3e500 R08: 0000000000000001 R09: ffff888056b3e523 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888056b3e520 R13: ffff88805ea2a848 R14: 0000000000000000 R15: ffff88805ea2a438 FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcaf1f3970 CR3: 000000000ed84000 CR4: 0000000000350ee0 Call Trace: ext4_stop_mmpd+0x47/0xd0 fs/ext4/mmp.c:254 ext4_put_super+0x87c/0xf90 fs/ext4/super.c:1263 generic_shutdown_super+0x142/0x370 fs/super.c:464 kill_block_super+0x9d/0xf0 fs/super.c:1446 deactivate_locked_super+0x99/0x160 fs/super.c:335 deactivate_super+0xad/0xd0 fs/super.c:366 cleanup_mnt+0x396/0x500 fs/namespace.c:1118 task_work_run+0xe2/0x1a0 kernel/task_work.c:151 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xc1b/0x2770 kernel/exit.c:811 do_group_exit+0x125/0x310 kernel/exit.c:908 get_signal+0x469/0x2200 kernel/signal.c:2758 arch_do_signal+0x88/0x1b70 arch/x86/kernel/signal.c:805 exit_to_user_mode_loop kernel/entry/common.c:161 [inline] exit_to_user_mode_prepare+0xf7/0x160 kernel/entry/common.c:191 syscall_exit_to_user_mode+0x38/0x230 kernel/entry/common.c:266 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x466609 Code: Unable to access opcode bytes at RIP 0x4665df. RSP: 002b:00007f89a6428218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000056c040 RCX: 0000000000466609 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056c040 RBP: 000000000056c038 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c044 R13: 00007fffa5f560ef R14: 00007f89a6428300 R15: 0000000000022000 irq event stamp: 3953 hardirqs last enabled at (3961): [] console_unlock+0x929/0xb30 kernel/printk/printk.c:2552 hardirqs last disabled at (3970): [] console_unlock+0x835/0xb30 kernel/printk/printk.c:2467 softirqs last enabled at (2406): [] __mark_inode_dirty+0xab9/0xf10 fs/fs-writeback.c:2334 softirqs last disabled at (2402): [] spin_lock_bh include/linux/spinlock.h:359 [inline] softirqs last disabled at (2402): [] wb_wakeup_delayed+0x62/0xf0 mm/backing-dev.c:269 ---[ end trace 85dbd558f859f4f5 ]--- ================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_write include/linux/instrumented.h:86 [inline] BUG: KASAN: null-ptr-deref in set_bit include/asm-generic/bitops/instrumented-atomic.h:28 [inline] BUG: KASAN: null-ptr-deref in kthread_stop+0x143/0x610 kernel/kthread.c:618 Write of size 8 at addr 0000000000000000 by task syz-executor.5/10509 CPU: 1 PID: 10509 Comm: syz-executor.5 Tainted: G W 5.10.56 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:118 __kasan_report mm/kasan/report.c:549 [inline] kasan_report.cold+0x6a/0x7c mm/kasan/report.c:562 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0xf9/0x1e0 mm/kasan/generic.c:192 instrument_atomic_write include/linux/instrumented.h:86 [inline] set_bit include/asm-generic/bitops/instrumented-atomic.h:28 [inline] kthread_stop+0x143/0x610 kernel/kthread.c:618 ext4_stop_mmpd+0x47/0xd0 fs/ext4/mmp.c:254 ext4_put_super+0x87c/0xf90 fs/ext4/super.c:1263 generic_shutdown_super+0x142/0x370 fs/super.c:464 kill_block_super+0x9d/0xf0 fs/super.c:1446 deactivate_locked_super+0x99/0x160 fs/super.c:335 deactivate_super+0xad/0xd0 fs/super.c:366 cleanup_mnt+0x396/0x500 fs/namespace.c:1118 task_work_run+0xe2/0x1a0 kernel/task_work.c:151 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xc1b/0x2770 kernel/exit.c:811 do_group_exit+0x125/0x310 kernel/exit.c:908 get_signal+0x469/0x2200 kernel/signal.c:2758 arch_do_signal+0x88/0x1b70 arch/x86/kernel/signal.c:805 exit_to_user_mode_loop kernel/entry/common.c:161 [inline] exit_to_user_mode_prepare+0xf7/0x160 kernel/entry/common.c:191 syscall_exit_to_user_mode+0x38/0x230 kernel/entry/common.c:266 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x466609 Code: Unable to access opcode bytes at RIP 0x4665df. RSP: 002b:00007f89a6428218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000056c040 RCX: 0000000000466609 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056c040 RBP: 000000000056c038 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c044 R13: 00007fffa5f560ef R14: 00007f89a6428300 R15: 0000000000022000 ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP KASAN NOPTI CPU: 1 PID: 10509 Comm: syz-executor.5 Tainted: G B W 5.10.56 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 RIP: 0010:arch_set_bit arch/x86/include/asm/bitops.h:55 [inline] RIP: 0010:set_bit include/asm-generic/bitops/instrumented-atomic.h:29 [inline] RIP: 0010:kthread_stop+0x143/0x610 kernel/kthread.c:618 Code: 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 79 04 00 00 48 8b 9d 70 05 00 00 be 08 00 00 00 48 89 df e8 9d a9 4e 00 80 0b 02 48 89 ef e8 d1 e9 ff ff 48 89 ef e8 79 ce 02 00 48 8d RSP: 0018:ffff88805e89f998 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff0a8a16f RDX: 0000000000000000 RSI: ffffffff8145c171 RDI: ffffffff83c5e444 RBP: ffff888056b3e500 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888056b3e520 R13: ffff88805ea2a848 R14: 0000000000000000 R15: ffff88805ea2a438 FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000000ed84000 CR4: 0000000000350ee0 Call Trace: ext4_stop_mmpd+0x47/0xd0 fs/ext4/mmp.c:254 ext4_put_super+0x87c/0xf90 fs/ext4/super.c:1263 generic_shutdown_super+0x142/0x370 fs/super.c:464 kill_block_super+0x9d/0xf0 fs/super.c:1446 deactivate_locked_super+0x99/0x160 fs/super.c:335 deactivate_super+0xad/0xd0 fs/super.c:366 cleanup_mnt+0x396/0x500 fs/namespace.c:1118 task_work_run+0xe2/0x1a0 kernel/task_work.c:151 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xc1b/0x2770 kernel/exit.c:811 do_group_exit+0x125/0x310 kernel/exit.c:908 get_signal+0x469/0x2200 kernel/signal.c:2758 arch_do_signal+0x88/0x1b70 arch/x86/kernel/signal.c:805 exit_to_user_mode_loop kernel/entry/common.c:161 [inline] exit_to_user_mode_prepare+0xf7/0x160 kernel/entry/common.c:191 syscall_exit_to_user_mode+0x38/0x230 kernel/entry/common.c:266 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x466609 Code: Unable to access opcode bytes at RIP 0x4665df. RSP: 002b:00007f89a6428218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000056c040 RCX: 0000000000466609 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056c040 RBP: 000000000056c038 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c044 R13: 00007fffa5f560ef R14: 00007f89a6428300 R15: 0000000000022000 Modules linked in: CR2: 0000000000000000 ---[ end trace 85dbd558f859f4f6 ]--- RIP: 0010:arch_set_bit arch/x86/include/asm/bitops.h:55 [inline] RIP: 0010:set_bit include/asm-generic/bitops/instrumented-atomic.h:29 [inline] RIP: 0010:kthread_stop+0x143/0x610 kernel/kthread.c:618 Code: 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 79 04 00 00 48 8b 9d 70 05 00 00 be 08 00 00 00 48 89 df e8 9d a9 4e 00 80 0b 02 48 89 ef e8 d1 e9 ff ff 48 89 ef e8 79 ce 02 00 48 8d RSP: 0018:ffff88805e89f998 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff0a8a16f RDX: 0000000000000000 RSI: ffffffff8145c171 RDI: ffffffff83c5e444 RBP: ffff888056b3e500 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888056b3e520 R13: ffff88805ea2a848 R14: 0000000000000000 R15: ffff88805ea2a438 FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000000ed84000 CR4: 0000000000350ee0 Fixing recursive fault but reboot is needed!