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.
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.
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.
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.