RAX: ffffffffffffffda RBX: 00007f5aeed9bf80 RCX: 00007f5aeec7cae9 RDX: 0000000020000040 RSI: 00000000404c4701 RDI: 0000000000000004 RBP: 00007f5aef96b120 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000006 R14: 00007f5aeed9bf80 R15: 00007ffc63f7ef98 BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 11124a067 P4D 11124a067 PUD 11127f067 PMD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 1 PID: 2649 Comm: syz-executor.0 Not tainted 6.5.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 RIP: 0010:strchr+0x4/0x30 lib/string.c:329 Code: c0 eb 0d 84 c9 74 18 48 83 c0 01 48 39 d0 74 0f 0f b6 0c 07 3a 0c 06 74 ea 19 c0 83 c8 01 c3 31 c0 c3 0f 1f 40 00 f3 0f 1e fa <0f> b6 07 89 f2 40 38 f0 75 0e eb 13 0f b6 47 01 48 83 c7 01 38 d0 RSP: 0018:ffffc90002b5bbd8 EFLAGS: 00010246 RAX: ffffc90002b5bc40 RBX: 0000000000000000 RCX: ffffc90002b5bbd4 RDX: ffffc90002b5bc20 RSI: 0000000000000025 RDI: 0000000000000000 RBP: ffffc90002b5bc20 R08: 00000000000000f2 R09: ffff888104bf2600 R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000cc0 R13: ffff888141a75ae0 R14: ffff888100aa6900 R15: 0000000000000000 FS: 00007f5aef96b6c0(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000011127d000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kvasprintf_const+0x1e/0xa0 lib/kasprintf.c:45 kobject_set_name_vargs+0x20/0x90 lib/kobject.c:272 kobject_add_varg lib/kobject.c:366 [inline] kobject_add+0x84/0x100 lib/kobject.c:424 device_add+0xe4/0x8d0 drivers/base/core.c:3562 tty_register_device_attr+0x102/0x220 drivers/tty/tty_io.c:3258 gsm_register_devices drivers/tty/n_gsm.c:653 [inline] gsm_activate_mux drivers/tty/n_gsm.c:3111 [inline] gsm_config drivers/tty/n_gsm.c:3357 [inline] gsmld_ioctl+0x5cf/0x6e0 drivers/tty/n_gsm.c:3735 tty_ioctl+0x2b8/0x890 drivers/tty/tty_io.c:2795 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x8b/0xc0 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f5aeec7cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5aef96b0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5aeed9bf80 RCX: 00007f5aeec7cae9 RDX: 0000000020000040 RSI: 00000000404c4701 RDI: 0000000000000004 RBP: 00007f5aef96b120 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000006 R14: 00007f5aeed9bf80 R15: 00007ffc63f7ef98 Modules linked in: CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:strchr+0x4/0x30 lib/string.c:329 Code: c0 eb 0d 84 c9 74 18 48 83 c0 01 48 39 d0 74 0f 0f b6 0c 07 3a 0c 06 74 ea 19 c0 83 c8 01 c3 31 c0 c3 0f 1f 40 00 f3 0f 1e fa <0f> b6 07 89 f2 40 38 f0 75 0e eb 13 0f b6 47 01 48 83 c7 01 38 d0 RSP: 0018:ffffc90002b5bbd8 EFLAGS: 00010246 RAX: ffffc90002b5bc40 RBX: 0000000000000000 RCX: ffffc90002b5bbd4 RDX: ffffc90002b5bc20 RSI: 0000000000000025 RDI: 0000000000000000 RBP: ffffc90002b5bc20 R08: 00000000000000f2 R09: ffff888104bf2600 R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000cc0 R13: ffff888141a75ae0 R14: ffff888100aa6900 R15: 0000000000000000 FS: 00007f5aef96b6c0(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000011127d000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: c0 eb 0d shr $0xd,%bl 3: 84 c9 test %cl,%cl 5: 74 18 je 0x1f 7: 48 83 c0 01 add $0x1,%rax b: 48 39 d0 cmp %rdx,%rax e: 74 0f je 0x1f 10: 0f b6 0c 07 movzbl (%rdi,%rax,1),%ecx 14: 3a 0c 06 cmp (%rsi,%rax,1),%cl 17: 74 ea je 0x3 19: 19 c0 sbb %eax,%eax 1b: 83 c8 01 or $0x1,%eax 1e: c3 ret 1f: 31 c0 xor %eax,%eax 21: c3 ret 22: 0f 1f 40 00 nopl 0x0(%rax) 26: f3 0f 1e fa endbr64 * 2a: 0f b6 07 movzbl (%rdi),%eax <-- trapping instruction 2d: 89 f2 mov %esi,%edx 2f: 40 38 f0 cmp %sil,%al 32: 75 0e jne 0x42 34: eb 13 jmp 0x49 36: 0f b6 47 01 movzbl 0x1(%rdi),%eax 3a: 48 83 c7 01 add $0x1,%rdi 3e: 38 d0 cmp %dl,%al