Re: Oops in hdac_hda_dev_probe (6.7-rc7)

[Takashi Iwai]

On Wed, 27 Dec 2023 08:37:07 +0100,
Dominik Brodowski wrote:
> 
> Hi,
> 
> unfortunately, the latest 6.7.0-rc7 and the two previous rc kernels cause an
> oops in hdac_hda_dev_probe(); sound and resume-from-suspend subsequently do
> not work:
> 
> 
> BUG: kernel NULL pointer dereference, address: 0000000000000078
> #PF: supervisor read access in kernel mode
> #PF: error_code(0x0000) - not-present page
> PGD 0
> P4D 0
> Oops: 0000 [#1] PREEMPT SMP NOPTI
> Hardware name: Dell Inc. XPS 9315/00KRKP, BIOS 1.1.3 05/11/2022
> Workqueue: events sof_probe_work
> 
> RIP: 0010:hdac_hda_dev_probe+0x42/0xf0
> Code: 48 8b 37 48 8b bb c8 04 00 00 e8 09 9b 0a 00 48 85 c0 48 89 c5 0f 84 a6 00 00 00 48 8b bb c8 04 00 00 48 89 c6 e8 1e 9a 0a 00 <41> 80 7c 24 78 00 75 46 b9 03 00 00 00 48 c7 c2 c0 b2 a1 ac 48 c7
> RSP: 0000:ffffc90000207b50 EFLAGS: 00010246
> 
> RAX: 0000000000000000 RBX: ffff88811495d000 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: ffff888108691600 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> R13: 0000000000000000 R14: 0000000000000000 R15: ffff88811400b028
> FS:  0000000000000000(0000) GS:ffff88886f500000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000078 CR3: 00000002b7a5a000 CR4: 0000000000f50ef0
> PKRU: 55555554
> Call Trace:
>  <TASK>
>  ? __die+0x1e/0x70
>  ? page_fault_oops+0x17c/0x4b0
>  ? snd_hdac_ext_bus_link_get+0x24/0xc0
>  ? exc_page_fault+0x462/0x8e0
>  ? asm_exc_page_fault+0x26/0x30
>  ? hdac_hda_dev_probe+0x42/0xf0
>  really_probe+0x166/0x300
>  ? __pfx___device_attach_driver+0x10/0x10
>  __driver_probe_device+0x6e/0x120
>  driver_probe_device+0x1a/0x90
>  __device_attach_driver+0x8e/0xd0
>  bus_for_each_drv+0x90/0xf0
>  __device_attach+0xac/0x1a0
>  bus_probe_device+0x93/0xb0
>  device_add+0x669/0x860
>  snd_hdac_device_register+0x10/0x60
>  hda_codec_probe_bus+0x189/0x290
>  hda_dsp_probe+0x211/0x550
>  sof_probe_work+0x2c/0x430
>  ? process_one_work+0x19c/0x500
>  process_one_work+0x205/0x500
>  worker_thread+0x1dc/0x3e0
> 
>  ? __pfx_worker_thread+0x10/0x10
>  kthread+0xea/0x120
>  ? __pfx_kthread+0x10/0x10
>  ret_from_fork+0x2c/0x50
>  ? __pfx_kthread+0x10/0x10
>  ret_from_fork_asm+0x1b/0x30
>  </TASK>
> Modules linked in:
> CR2: 0000000000000078
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:hdac_hda_dev_probe+0x42/0xf0
> Code: 48 8b 37 48 8b bb c8 04 00 00 e8 09 9b 0a 00 48 85 c0 48 89 c5 0f 84 a6 00 00 00 48 8b bb c8 04 00 00 48 89 c6 e8 1e 9a 0a 00 <41> 80 7c 24 78 00 75 46 b9 03 00 00 00 48 c7 c2 c0 b2 a1 ac 48 c7
> RSP: 0000:ffffc90000207b50 EFLAGS: 00010246
> RAX: 0000000000000000 RBX: ffff88811495d000 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: ffff888108691600 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> R13: 0000000000000000 R14: 0000000000000000 R15: ffff88811400b028
> FS:  0000000000000000(0000) GS:ffff88886f500000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000078 CR3: 00000002b7a5a000 CR4: 0000000000f50ef0
> PKRU: 55555554
> note: kworker/2:0[24] exited with irqs disabled
> 
> 
> I was able to bisect the issue to commit a0575b4add21 ("ASoC: hdac_hda:
> Conditionally register dais for HDMI and Analog"). Reverting that patch on
> top of mainline fixes it.

As I've been (and still am) off, I had too little time for taking a
deeper look now, unfortunately.  But my wild guess is that it's a NULL
dereference of the hdac_hda_priv referred via hdac dev.  If it's
correct, a oneliner like below should work around the crash.
Could you give it a try?


thanks,

Takashi

-- 8< --
--- a/sound/soc/codecs/hdac_hda.c
+++ b/sound/soc/codecs/hdac_hda.c
@@ -630,7 +630,7 @@ static int hdac_hda_dev_probe(struct hdac_device *hdev)
 	snd_hdac_ext_bus_link_get(hdev->bus, hlink);
 
 	/* ASoC specific initialization */
-	if (hda_pvt->need_display_power)
+	if (hda_pvt && hda_pvt->need_display_power)
 		ret = devm_snd_soc_register_component(&hdev->dev,
 						&hdac_hda_hdmi_codec, hdac_hda_hdmi_dais,
 						ARRAY_SIZE(hdac_hda_hdmi_dais));