CVE-2026-46049

In the Linux kernel, the following vulnerability has been resolved:

ALSA: ctxfi: Add fallback to default RSR for S/PDIF

spdifpassthruplaybackgetresources() uses atc->pllrate as the RSR for the MSR calculation loop. However, pllrate is only updated in atcpllinit() and not in hwpllinit(), so it remains 0 after the card init.

When spdifpassthruplaybacksetup() skips atcpll_init() for 32000 Hz, (rsr * desc.msr) always becomes 0, causing the loop to spin indefinitely.

Add fallback to use atc->rsr when atc->pllrate is 0. This reflects the hardware state, since hwcard_init() already configures the PLL to the default RSR.