media: usbtv: keep device alive while ALSA card exists

Summary

In the Linux kernel, the following vulnerability has been resolved: media: usbtv: keep device alive while ALSA card exists The ALSA PCM callbacks store the driver state in pcm->private_data. An open PCM file can outlive USB disconnect because usbtv_audio_free() uses snd_card_free_when_closed(). The disconnect path can then drop the V4L2 device reference and free struct usbtv before ALSA releases the substream, so a later close dereferences freed memory in snd_usbtv_pcm_close(). Take a V4L2 device reference for the ALSA card and drop it from the card private_free callback. This keeps struct usbtv valid until ALSA has closed the remaining files and freed the card.

Timeline

1. Sep 16, 2026, 10:33 AM UTCCVE published
2. Oct 19, 2026, 8:56 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 63ddf68de52efaac40a9287e44266ac30e71dd36 · fixed in 97b5e8b22b98e287481a97a9a4cfebbb348738a5; From 63ddf68de52efaac40a9287e44266ac30e71dd36 · fixed in 503be26ff888cb3576e55d251895d290e8146f27; From 63ddf68de52efaac40a9287e44266ac30e71dd36 · fixed in be0f7745f883386e5263b4e475686a81dfa87175; From 63ddf68de52efaac40a9287e44266ac30e71dd36 · fixed in 67374e3a00814dcdd46e9feca61f69f7f2d81957; From 63ddf68de52efaac40a9287e44266ac30e71dd36 · fixed in 239d1683e08b2aee2a15ef35706e1ea9a76681d8; From 63ddf68de52efaac40a9287e44266ac30e71dd36 · fixed in 7690a86b193271322cd31ab77349a87aa10858e4; From 63ddf68de52efaac40a9287e44266ac30e71dd36 · fixed in 1618257cb0aba4ce342ae8c0228368c24161f5fb; From 63ddf68de52efaac40a9287e44266ac30e71dd36 · fixed in fc530fe168bb2b745a93f553ad21fc25fd9cba3d

• Linux Linux

  3.18

• KernelLinux

  From 3.18.0 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.51; From 6.19.0 · fixed in 7.2.5

References 8