[Bug 299952] snd_envy24ht: Kernel page fault in envy24ht_r16sl() on FreeBSD 15.1-RELEASE-p6

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=299952

            Bug ID: 299952
           Summary: snd_envy24ht: Kernel page fault in envy24ht_r16sl() on
                    FreeBSD 15.1-RELEASE-p6
           Product: Base System
           Version: 15.1-STABLE
          Hardware: amd64
                OS: Any
            Status: New
          Severity: Affects Only Me
          Priority: ---
         Component: kern
          Assignee: bugs@FreeBSD.org
          Reporter: cizmarmatija44@gmail.com

On October 23, 2026, my FreeBSD 15.1-RELEASE-p6 system experienced an
unexpected kernel panic and automatic reboot shortly after logging into KDE
Plasma Wayland.

Immediately after logging in through SDDM, the screen turned black with only
the mouse pointer visible. The system then restarted without user intervention.

After rebooting, FreeBSD's `savecore` utility successfully saved a kernel crash
dump. I installed GDB and examined the dump using the matching kernel debugging
symbols.

The backtrace shows that the page fault occurred inside the FreeBSD
`snd_envy24ht` sound driver.

### System information

- FreeBSD 15.1-RELEASE-p6, amd64, GENERIC kernel
- Installation method: pkgbase
- Sound card: Terratec PHASE 22 (VIA Envy24HT)
- Audio driver: `snd_envy24ht`
- Desktop: KDE Plasma 6.7.5, Wayland
- Display manager: SDDM
- GPU: NVIDIA GeForce RTX 2060
- NVIDIA driver: 595.104.02
- Motherboard: ASRock H97 Pro4
- CPU: Intel Core i7-4790S

### Panic information

```text
Fatal trap 12: page fault while in kernel mode
fault code = supervisor read data, page not present
current process = 12 (irq19: pcm7)
panic: page fault
Uptime: 4m8s
```

### Relevant kernel backtrace

```text
#8  envy24ht_r16sl()
    /usr/src/sys/dev/sound/pci/envy24ht.c:1455

#9  envy24htchan_trigger()
    /usr/src/sys/dev/sound/pci/envy24ht.c:1686

#10 CHANNEL_TRIGGER()
#11 chn_trigger()
#12 chn_rdintr()
#13 chn_intr()

#14 envy24ht_intr()
    /usr/src/sys/dev/sound/pci/envy24ht.c:2003

#15 intr_event_execute_handlers()
#17 ithread_loop()
```

The crash occurred in an audio interrupt thread and appears to involve the
`snd_envy24ht` driver.

### Crash dump

```text
Crash time: 2026-10-23 20:22:59 +0200
Panic String: page fault
Dump Status: good
Dump file: /var/crash/vmcore.0
```

The crash dump has been preserved locally.

### Expected behavior

The system should continue operating normally when starting KDE Plasma Wayland
and initializing audio devices.

### Actual behavior

The system experienced a kernel-mode page fault inside `envy24ht_r16sl()` and
rebooted automatically.

This occurred once so far and is not reliably reproducible.

### Additional notes

The FreeBSD kernel dump indicates an audio-driver fault, although the issue
occurred during KDE Plasma Wayland startup.

The ZFS pool remained ONLINE, with no known data errors after restarting.

I would appreciate assistance investigating whether this is a bug in the
`snd_envy24ht` driver or its interaction with the FreeBSD PCM subsystem.

-- 
You are receiving this mail because:
You are the assignee for the bug.