BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 111b35067 P4D 111b35067 PUD 10e02b067 PMD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 1 PID: 4030 Comm: syz-executor.0 Not tainted 6.1.38-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 RIP: 0010:hci_uart_tty_ioctl+0x20a/0x320 drivers/bluetooth/hci_ldisc.c:774 Code: 87 0b 01 00 00 4d 89 77 20 31 ed e9 00 01 00 00 bd cf ff ff ff 49 f7 47 18 01 00 00 00 0f 84 ed 00 00 00 49 8b 87 b8 00 00 00 <8b> 28 e9 df 00 00 00 48 89 df 89 ee 4c 89 f2 5b 41 5e 41 5f 5d e9 RSP: 0018:ffffc900033cbe90 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff888114343000 RCX: ffffffff82d81fa0 RDX: 0000000000000000 RSI: 00000000800455c9 RDI: ffff888114343000 RBP: 00000000ffffffcf R08: ffff888113d2d580 R09: 0000000000000000 R10: 0000000000000000 R11: 0000001000000000 R12: 0000000000000000 R13: ffff888100f24e00 R14: 0000000000000000 R15: ffff8881183e2c00 FS: 00007f04dd256700(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000118875000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tty_ioctl+0x2a5/0x490 drivers/tty/tty_io.c:2782 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0x6a/0xb0 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f04dc48c169 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:00007f04dd256168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f04dc5ac050 RCX: 00007f04dc48c169 RDX: 0000000000000000 RSI: 00000000800455c9 RDI: 0000000000000003 RBP: 00007f04dc4e7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd6a94209f R14: 00007f04dd256300 R15: 0000000000022000 Modules linked in: CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:hci_uart_tty_ioctl+0x20a/0x320 drivers/bluetooth/hci_ldisc.c:774 Code: 87 0b 01 00 00 4d 89 77 20 31 ed e9 00 01 00 00 bd cf ff ff ff 49 f7 47 18 01 00 00 00 0f 84 ed 00 00 00 49 8b 87 b8 00 00 00 <8b> 28 e9 df 00 00 00 48 89 df 89 ee 4c 89 f2 5b 41 5e 41 5f 5d e9 RSP: 0018:ffffc900033cbe90 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff888114343000 RCX: ffffffff82d81fa0 RDX: 0000000000000000 RSI: 00000000800455c9 RDI: ffff888114343000 RBP: 00000000ffffffcf R08: ffff888113d2d580 R09: 0000000000000000 R10: 0000000000000000 R11: 0000001000000000 R12: 0000000000000000 R13: ffff888100f24e00 R14: 0000000000000000 R15: ffff8881183e2c00 FS: 00007f04dd256700(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000118875000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 87 0b xchg %ecx,(%rbx) 2: 01 00 add %eax,(%rax) 4: 00 4d 89 add %cl,-0x77(%rbp) 7: 77 20 ja 0x29 9: 31 ed xor %ebp,%ebp b: e9 00 01 00 00 jmpq 0x110 10: bd cf ff ff ff mov $0xffffffcf,%ebp 15: 49 f7 47 18 01 00 00 testq $0x1,0x18(%r15) 1c: 00 1d: 0f 84 ed 00 00 00 je 0x110 23: 49 8b 87 b8 00 00 00 mov 0xb8(%r15),%rax * 2a: 8b 28 mov (%rax),%ebp <-- trapping instruction 2c: e9 df 00 00 00 jmpq 0x110 31: 48 89 df mov %rbx,%rdi 34: 89 ee mov %ebp,%esi 36: 4c 89 f2 mov %r14,%rdx 39: 5b pop %rbx 3a: 41 5e pop %r14 3c: 41 5f pop %r15 3e: 5d pop %rbp 3f: e9 .byte 0xe9