High · published February 4, 2026
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Fix use-after-free in snd_usb_mixer_free()
When snd_usb_create_mixer() fails, snd_usb_mixer_free() frees
mixer->id_elems but the controls already added to the card still
reference the freed memory. Later when snd_card_register() runs,
the OSS mixer layer calls their callbacks and hits a use-after-free read.
Call trace:
get_ctl_value+0x63f/0x820 sound/usb/mixer.c:411
get_min_max_with_quirks.isra.0+0x240/0x1f40 sound/usb/mixer.c:1241
mixer_ctl_feature_info+0x26b/0x490 sound/usb/mixer.c:1381
snd_mixer_oss_build_test+0x174/0x3a0 sound/core/oss/mixer_oss.c:887
...
snd_card_register+0x4ed/0x6d0 sound/core/init.c:923
usb_audio_probe+0x5ef/0x2a90 sound/usb/card.c:1025
Fix by calling snd_ctl_remove() for all mixer controls before freeing
id_elems. We save the next pointer first because snd_ctl_remove()
frees the current element.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 2.6.13, < 5.10.249 | 5.10.249 |
| linux/linux_kernel | ≥ 5.11, < 5.15.199 | 5.15.199 |
| linux/linux_kernel | ≥ 5.16, < 6.1.162 | 6.1.162 |
| linux/linux_kernel | ≥ 6.2, < 6.6.122 | 6.6.122 |
| linux/linux_kernel | ≥ 6.7, < 6.12.68 | 6.12.68 |
| linux/linux_kernel | ≥ 6.13, < 6.18.8 | 6.18.8 |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |