kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 1652 Comm: syz-executor.0 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 RIP: 0010:cdev_del+0x22/0x90 fs/char_dev.c:602 Code: cf 0f 1f 80 00 00 00 00 55 48 89 fd 48 83 ec 08 e8 b3 dc be ff 48 8d 7d 64 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 4f 48 RSP: 0018:ffff888045e07a48 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffff888238962400 RCX: ffffc9000843a000 RDX: 000000000000000c RSI: ffffffff81a3a8bd RDI: 0000000000000064 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000000 R12: ffff888238962408 R13: ffff8882389c43c8 R14: ffff8880a315b3c0 R15: ffff888049659078 FS: 00007fa0d7823700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9c1bb2e263 CR3: 000000009384e000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tty_unregister_device drivers/tty/tty_io.c:3054 [inline] tty_unregister_device+0x112/0x1b0 drivers/tty/tty_io.c:3049 gsmld_detach_gsm drivers/tty/n_gsm.c:2289 [inline] gsmld_close+0xaa/0x1f0 drivers/tty/n_gsm.c:2358 tty_ldisc_close+0xa2/0xd0 drivers/tty/tty_ldisc.c:493 tty_ldisc_kill drivers/tty/tty_ldisc.c:639 [inline] tty_ldisc_release+0xf5/0x440 drivers/tty/tty_ldisc.c:806 tty_release_struct+0x20/0xe0 drivers/tty/tty_io.c:1611 tty_release+0xc70/0x1210 drivers/tty/tty_io.c:1784 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 get_signal+0x1b64/0x1f70 kernel/signal.c:2400 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fa0d92b10f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa0d7823168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007fa0d93d0f80 RCX: 00007fa0d92b10f9 RDX: 0000000020000080 RSI: 0000000000005423 RDI: 0000000000000005 RBP: 00007fa0d78231d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffde50dcc8f R14: 00007fa0d7823300 R15: 0000000000022000 Modules linked in: ---[ end trace 5182f5785f37f571 ]--- RIP: 0010:cdev_del+0x22/0x90 fs/char_dev.c:602 Code: cf 0f 1f 80 00 00 00 00 55 48 89 fd 48 83 ec 08 e8 b3 dc be ff 48 8d 7d 64 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 4f 48 RSP: 0018:ffff888045e07a48 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffff888238962400 RCX: ffffc9000843a000 RDX: 000000000000000c RSI: ffffffff81a3a8bd RDI: 0000000000000064 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000000 R12: ffff888238962408 R13: ffff8882389c43c8 R14: ffff8880a315b3c0 R15: ffff888049659078 FS: 00007fa0d7823700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feedce4b008 CR3: 000000009384e000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: cf iret 1: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 8: 55 push %rbp 9: 48 89 fd mov %rdi,%rbp c: 48 83 ec 08 sub $0x8,%rsp 10: e8 b3 dc be ff callq 0xffbedcc8 15: 48 8d 7d 64 lea 0x64(%rbp),%rdi 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx <-- trapping instruction 2e: 48 89 f8 mov %rdi,%rax 31: 83 e0 07 and $0x7,%eax 34: 83 c0 03 add $0x3,%eax 37: 38 d0 cmp %dl,%al 39: 7c 04 jl 0x3f 3b: 84 d2 test %dl,%dl 3d: 75 4f jne 0x8e 3f: 48 rex.W