BUG: kernel NULL pointer dereference, address: 0000000000000004 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 1 PID: 19757 Comm: syz-executor.1 Not tainted 5.4.0-rc4+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_set_bit arch/x86/include/asm/bitops.h:55 [inline] RIP: 0010:set_bit include/asm-generic/bitops-instrumented.h:29 [inline] RIP: 0010:io_wq_cancel_all+0x22/0x210 fs/io-wq.c:574 Code: e9 3a ff ff ff 0f 1f 00 55 be 08 00 00 00 48 89 e5 41 57 49 89 ff 48 83 c7 08 41 56 41 55 41 54 53 48 83 ec 08 e8 3e 66 e1 ff 41 80 4f 08 02 e8 63 99 9d ff 31 d2 45 31 c9 45 31 c0 31 f6 68 RSP: 0018:ffff888081f179a8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88809cc67000 RCX: ffffffff81b9e932 RDX: 0000000000000001 RSI: 0000000000000008 RDI: 0000000000000004 RBP: ffff888081f179d8 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809cc673d0 R13: ffff88809cc67078 R14: ffff88809cc67380 R15: fffffffffffffffc FS: 0000000000000000(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000004 CR3: 000000000846d000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: io_ring_ctx_wait_and_kill+0x1a4/0x610 fs/io_uring.c:3679 io_uring_release+0x3d/0x50 fs/io_uring.c:3691 __fput+0x25a/0x770 fs/file_table.c:280 ____fput+0x9/0x10 fs/file_table.c:313 task_work_run+0x108/0x180 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9d4/0x2c70 kernel/exit.c:817 do_group_exit+0xf4/0x2e0 kernel/exit.c:921 get_signal+0x36c/0x1d50 kernel/signal.c:2734 do_signal+0x87/0x1710 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x114/0x2e0 arch/x86/entry/common.c:159 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath+0x369/0x410 arch/x86/entry/common.c:274 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:344 RIP: 0033:0x45c909 Code: Bad RIP value. RSP: 002b:00007f5d80ca1db0 EFLAGS: 00000202 ORIG_RAX: 0000000000000038 RAX: 0000000000000000 RBX: 00007f5d80ca2700 RCX: 000000000045c909 RDX: 00007f5d80ca29d0 RSI: 00007f5d80ca1db0 RDI: 00000000003d0f00 RBP: 00007ffc07e9f750 R08: 00007f5d80ca2700 R09: 00007f5d80ca2700 R10: 00007f5d80ca29d0 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ffc07e9f5ef R14: 00007f5d80ca29c0 R15: 000000000075bfd4 Modules linked in: CR2: 0000000000000004 ---[ end trace 8467466421cbe904 ]--- RIP: 0010:arch_set_bit arch/x86/include/asm/bitops.h:55 [inline] RIP: 0010:set_bit include/asm-generic/bitops-instrumented.h:29 [inline] RIP: 0010:io_wq_cancel_all+0x22/0x210 fs/io-wq.c:574 Code: e9 3a ff ff ff 0f 1f 00 55 be 08 00 00 00 48 89 e5 41 57 49 89 ff 48 83 c7 08 41 56 41 55 41 54 53 48 83 ec 08 e8 3e 66 e1 ff 41 80 4f 08 02 e8 63 99 9d ff 31 d2 45 31 c9 45 31 c0 31 f6 68 RSP: 0018:ffff888081f179a8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88809cc67000 RCX: ffffffff81b9e932 RDX: 0000000000000001 RSI: 0000000000000008 RDI: 0000000000000004 RBP: ffff888081f179d8 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809cc673d0 R13: ffff88809cc67078 R14: ffff88809cc67380 R15: fffffffffffffffc FS: 0000000000000000(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000045c8df CR3: 000000000846d000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400