kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 24401 Comm: syz-executor.3 Not tainted 5.4.265-syzkaller-00033-g4d7b888b5774 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0010:__hlist_del include/linux/list.h:791 [inline] RIP: 0010:detach_timer kernel/time/timer.c:824 [inline] RIP: 0010:detach_if_pending+0x179/0x360 kernel/time/timer.c:841 Code: e8 03 42 80 3c 20 00 74 08 48 89 ef e8 90 6c 3f 00 48 89 5d 00 48 85 db 74 46 e8 c2 9a 0f 00 48 83 c3 08 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 68 6c 3f 00 48 89 2b 80 7c 24 0c RSP: 0018:ffff8881dff7f690 EFLAGS: 00010802 RAX: 1bd5a00000000025 RBX: dead00000000012a RCX: ffff8881e469bf00 RDX: 0000000000000000 RSI: 000000001fc00001 RDI: 0000000080400000 RBP: ffff8881bf172268 R08: ffffffff8154ab0a R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000 R13: ffff8881e5aef1c0 R14: ffff8881e5aef1c8 R15: 1ffff1103cb5de39 FS: 00007fc74824c6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2b0890b978 CR3: 00000001c0290000 CR4: 00000000003406a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: try_to_del_timer_sync kernel/time/timer.c:1238 [inline] del_timer_sync+0x13c/0x230 kernel/time/timer.c:1379 tun_flow_uninit+0x2c/0x280 drivers/net/tun.c:1451 tun_free_netdev+0x77/0x190 drivers/net/tun.c:2401 netdev_run_todo+0xb7f/0xdf0 net/core/dev.c:9450 tun_detach drivers/net/tun.c:765 [inline] tun_chr_close+0xc1/0x130 drivers/net/tun.c:3557 __fput+0x262/0x680 fs/file_table.c:281 task_work_run+0x140/0x170 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xcaf/0x2bc0 kernel/exit.c:859 do_group_exit+0x138/0x300 kernel/exit.c:982 get_signal+0xdb1/0x1440 kernel/signal.c:2735 do_signal+0xb0/0x11f0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0xc0/0x1a0 arch/x86/entry/common.c:159 prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194 ret_from_intr+0x1c/0x1c Modules linked in: ---[ end trace 724c71e0e016c264 ]--- RIP: 0010:__hlist_del include/linux/list.h:791 [inline] RIP: 0010:detach_timer kernel/time/timer.c:824 [inline] RIP: 0010:detach_if_pending+0x179/0x360 kernel/time/timer.c:841 Code: e8 03 42 80 3c 20 00 74 08 48 89 ef e8 90 6c 3f 00 48 89 5d 00 48 85 db 74 46 e8 c2 9a 0f 00 48 83 c3 08 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 68 6c 3f 00 48 89 2b 80 7c 24 0c RSP: 0018:ffff8881dff7f690 EFLAGS: 00010802 RAX: 1bd5a00000000025 RBX: dead00000000012a RCX: ffff8881e469bf00 RDX: 0000000000000000 RSI: 000000001fc00001 RDI: 0000000080400000 RBP: ffff8881bf172268 R08: ffffffff8154ab0a R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000 R13: ffff8881e5aef1c0 R14: ffff8881e5aef1c8 R15: 1ffff1103cb5de39 FS: 00007fc74824c6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2b0890b978 CR3: 00000001c0290000 CR4: 00000000003406a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: e8 03 42 80 3c call 0x3c804208 5: 20 00 and %al,(%rax) 7: 74 08 je 0x11 9: 48 89 ef mov %rbp,%rdi c: e8 90 6c 3f 00 call 0x3f6ca1 11: 48 89 5d 00 mov %rbx,0x0(%rbp) 15: 48 85 db test %rbx,%rbx 18: 74 46 je 0x60 1a: e8 c2 9a 0f 00 call 0xf9ae1 1f: 48 83 c3 08 add $0x8,%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 68 6c 3f 00 call 0x3f6ca1 39: 48 89 2b mov %rbp,(%rbx) 3c: 80 .byte 0x80 3d: 7c 24 jl 0x63 3f: 0c .byte 0xc