CVE-2026-46049: ALSA: ctxfi: Add fallback to default RSR for S/PDIF

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-27 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: ctxfi: Add fallback to default RSR for S/PDIF spdif_passthru_playback_get_resources() uses atc->pll_rate as the RSR for the MSR calculation loop. However, pll_rate is only updated in atc_pll_init() and not in hw_pll_init(), so it remains 0 after the card init. When spdif_passthru_playback_setup() skips atc_pll_init() for 32000 Hz, (rsr * desc.msr) always becomes 0, causing the loop to spin indefinitely. Add fallback to use atc->rsr when atc->pll_rate is 0. This reflects the hardware state, since hw_card_init() already configures the PLL to the default RSR.

Affected products

Linux kernel: from 2.6.31 before 5.10.258; from 5.11 before 5.15.209; from 5.16 before 6.1.175; from 6.2 before 6.6.140; from 6.7 before 6.12.86; from 6.13 before 6.18.27 — fixed in 5.10.258, 5.15.209, 6.1.175, 6.12.86, 6.18.27, 6.6.140

How to fix

Upgrade to a fixed version: Linux kernel 5.10.258, 5.15.209, 6.1.175, 6.12.86. Check the vendor advisory for mitigations.

References

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