Re: [syzbot] [kernel?] general protection fault in tty_register_device_attr

[Thomas Weißschuh]

On 2023-09-01 20:05:59-0700, syzbot wrote:
> [..]

> general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
> CPU: 1 PID: 5046 Comm: syz-executor362 Not tainted 6.5.0-next-20230828-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
> RIP: 0010:strchr+0x1b/0xb0 lib/string.c:329
> Code: a3 ac f7 48 8b 74 24 08 48 8b 14 24 eb 89 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 48 89 fa 55 48 c1 ea 03 53 48 83 ec 10 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 51 0f b6 07 89
> RSP: 0018:ffffc90003a1f800 EFLAGS: 00010286
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: 0000000000000025 RDI: 0000000000000000
> RBP: ffffc90003a1f890 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000000 R12: ffffc90003a1f890
> R13: 0000000000000cc0 R14: ffff888014a96000 R15: 0000000000000001
> FS:  0000555556b43480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00005584fe812978 CR3: 00000000729c5000 CR4: 00000000003506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  kvasprintf_const+0x25/0x190 lib/kasprintf.c:45
>  kobject_set_name_vargs+0x5a/0x130 lib/kobject.c:272
>  kobject_add_varg lib/kobject.c:366 [inline]
>  kobject_add+0x12a/0x240 lib/kobject.c:424
>  device_add+0x290/0x1ac0 drivers/base/core.c:3560
>  tty_register_device_attr+0x38f/0x7b0 drivers/tty/tty_io.c:3248
>  gsm_register_devices drivers/tty/n_gsm.c:654 [inline]
>  gsm_activate_mux+0x157/0x2d0 drivers/tty/n_gsm.c:3138
>  gsm_config drivers/tty/n_gsm.c:3383 [inline]
>  gsmld_ioctl+0x8cc/0x1550 drivers/tty/n_gsm.c:3786
>  tty_ioctl+0x706/0x1580 drivers/tty/tty_io.c:2785
>  vfs_ioctl fs/ioctl.c:51 [inline]
>  __do_sys_ioctl fs/ioctl.c:871 [inline]
>  __se_sys_ioctl fs/ioctl.c:857 [inline]
>  __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd

> [..]

#syz dup: general protection fault in netdev_register_kobject

With patch from Andy:

https://lore.kernel.org/all/20230828145824.3895288-1-andriy.shevchenko@xxxxxxxxxxxxxxx/