Re: Crash in new PHY link topology extension

[Maxime Chevallier <maxime.chevallier@bootlin.com>]

Hello Heiner,

On Fri, 12 Apr 2024 12:03:35 +0200
Heiner Kallweit <hkallweit1@gmail.com> wrote:

> On 12.04.2024 12:00, Heiner Kallweit wrote:
> > On today's linux-next I get the following.
> > 
> > Apr 12 11:36:03 zotac kernel: BUG: kernel NULL pointer dereference, address: 0000000000000018
> > Apr 12 11:36:03 zotac kernel: #PF: supervisor read access in kernel mode
> > Apr 12 11:36:03 zotac kernel: #PF: error_code(0x0000) - not-present page
> > Apr 12 11:36:03 zotac kernel: PGD 0 P4D 0
> > Apr 12 11:36:03 zotac kernel: Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
> > Apr 12 11:36:03 zotac kernel: CPU: 1 PID: 219 Comm: systemd-network Not tainted 6.9.0-rc3-next-20240412+ #2
> > Apr 12 11:36:03 zotac kernel: Hardware name: Default string Default string/Default string, BIOS ADLN.M6.SODIMM.ZB.CY.015 08/08/2023
> > Apr 12 11:36:03 zotac kernel: RIP: 0010:__lock_acquire+0x5d/0x2550
> > Apr 12 11:36:03 zotac kernel: Code: 65 4c 8b 35 65 5d d1 7e 45 85 db 0f 84 bd 06 00 00 44 8b 15 f5 f8 14 01 45 89 c3 41 89 d7 45 89 c8 45 85
> >  d2 0f 84 c5 02 00 00 <48> 81 3f 00 f3 8a 82 44 0f 44 d8 83 fe 01 0f 86 bd 02 00 00 31 d2
> > Apr 12 11:36:03 zotac kernel: RSP: 0018:ffff9ca180e6f498 EFLAGS: 00010002
> > Apr 12 11:36:03 zotac kernel: RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> > Apr 12 11:36:03 zotac kernel: RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000018
> > Apr 12 11:36:03 zotac kernel: RBP: ffff9ca180e6f510 R08: 0000000000000000 R09: 0000000000000000
> > Apr 12 11:36:03 zotac kernel: R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001
> > Apr 12 11:36:03 zotac kernel: R13: 0000000000000000 R14: ffff98e7c5b38000 R15: 0000000000000000
> > Apr 12 11:36:03 zotac kernel: FS:  00007f7e7440e0c0(0000) GS:ffff98e937a80000(0000) knlGS:0000000000000000
> > Apr 12 11:36:03 zotac kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > Apr 12 11:36:03 zotac kernel: CR2: 0000000000000018 CR3: 00000001027c0000 CR4: 0000000000750ef0
> > Apr 12 11:36:03 zotac kernel: PKRU: 55555554
> > Apr 12 11:36:03 zotac kernel: Call Trace:
> > Apr 12 11:36:03 zotac kernel:  <TASK>
> > Apr 12 11:36:03 zotac kernel:  ? show_regs+0x5f/0x70
> > Apr 12 11:36:03 zotac kernel:  ? __die+0x1f/0x70
> > Apr 12 11:36:03 zotac kernel:  ? page_fault_oops+0x15a/0x450
> > Apr 12 11:36:03 zotac kernel:  ? debug_smp_processor_id+0x17/0x20
> > Apr 12 11:36:03 zotac kernel:  ? rcu_is_watching+0x11/0x50
> > Apr 12 11:36:03 zotac kernel:  ? exc_page_fault+0x4cb/0x8d0
> > Apr 12 11:36:03 zotac kernel:  ? asm_exc_page_fault+0x27/0x30
> > Apr 12 11:36:03 zotac kernel:  ? __lock_acquire+0x5d/0x2550
> > Apr 12 11:36:03 zotac kernel:  ? __lock_acquire+0x3f8/0x2550
> > Apr 12 11:36:03 zotac kernel:  lock_acquire+0xc8/0x2f0
> > Apr 12 11:36:03 zotac kernel:  ? phy_link_topo_add_phy+0x153/0x1a0 [libphy]
> > Apr 12 11:36:03 zotac kernel:  _raw_spin_lock+0x2d/0x40
> > Apr 12 11:36:03 zotac kernel:  ? phy_link_topo_add_phy+0x153/0x1a0 [libphy]
> > Apr 12 11:36:03 zotac kernel:  phy_link_topo_add_phy+0x153/0x1a0 [libphy]
> > Apr 12 11:36:03 zotac kernel:  phy_attach_direct+0xcd/0x410 [libphy]
> > Apr 12 11:36:03 zotac kernel:  ? __pfx_r8169_phylink_handler+0x10/0x10 [r8169]
> > Apr 12 11:36:03 zotac kernel:  phy_connect_direct+0x21/0x70 [libphy]
> > Apr 12 11:36:03 zotac kernel:  rtl_open+0x30c/0x4f0 [r8169]
> > Apr 12 11:36:03 zotac kernel:  __dev_open+0xe8/0x1a0
> > Apr 12 11:36:03 zotac kernel:  __dev_change_flags+0x1c5/0x240
> > Apr 12 11:36:03 zotac kernel:  dev_change_flags+0x22/0x70
> > Apr 12 11:36:03 zotac kernel:  do_setlink+0xe9f/0x1290
> > Apr 12 11:36:03 zotac kernel:  ? __nla_validate_parse+0x60/0xce0
> > Apr 12 11:36:03 zotac kernel:  rtnl_setlink+0xff/0x190
> > Apr 12 11:36:03 zotac kernel:  ? __this_cpu_preempt_check+0x13/0x20
> > Apr 12 11:36:03 zotac kernel:  rtnetlink_rcv_msg+0x16e/0x660
> > Apr 12 11:36:03 zotac kernel:  ? __pfx_rtnetlink_rcv_msg+0x10/0x10
> > Apr 12 11:36:03 zotac kernel:  netlink_rcv_skb+0x5a/0x110
> > Apr 12 11:36:03 zotac kernel:  rtnetlink_rcv+0x10/0x20
> > Apr 12 11:36:03 zotac kernel:  netlink_unicast+0x1a2/0x290
> > Apr 12 11:36:03 zotac kernel:  netlink_sendmsg+0x1f9/0x420
> > Apr 12 11:36:03 zotac kernel:  __sys_sendto+0x1d0/0x1e0
> > Apr 12 11:36:03 zotac kernel:  ? __seccomp_filter+0x22e/0x3b0
> > Apr 12 11:36:03 zotac kernel:  __x64_sys_sendto+0x1f/0x30
> > Apr 12 11:36:03 zotac kernel:  do_syscall_64+0x6c/0x140
> > Apr 12 11:36:03 zotac kernel:  entry_SYSCALL_64_after_hwframe+0x76/0x7e  

I've had another similar report, I'll send a fix right-away.

Thanks for the report,

Maxime

> 
> Seems phy_link_topo_add_phy() can't deal with argument topo being NULL.
>