CVE-2026-31602

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ALSA: ctxfi: Limit PTP to a single page<br /> <br /> Commit 391e69143d0a increased CT_PTP_NUM from 1 to 4 to support 256<br /> playback streams, but the additional pages are not used by the card<br /> correctly. The CT20K2 hardware already has multiple VMEM_PTPAL<br /> registers, but using them separately would require refactoring the<br /> entire virtual memory allocation logic.<br /> <br /> ct_vm_map() always uses PTEs in vm-&gt;ptp[0].area regardless of<br /> CT_PTP_NUM. On AMD64 systems, a single PTP covers 512 PTEs (2M). When<br /> aggregate memory allocations exceed this limit, ct_vm_map() tries to<br /> access beyond the allocated space and causes a page fault:<br /> <br /> BUG: unable to handle page fault for address: ffffd4ae8a10a000<br /> Oops: Oops: 0002 [#1] SMP PTI<br /> RIP: 0010:ct_vm_map+0x17c/0x280 [snd_ctxfi]<br /> Call Trace:<br /> atc_pcm_playback_prepare+0x225/0x3b0<br /> ct_pcm_playback_prepare+0x38/0x60<br /> snd_pcm_do_prepare+0x2f/0x50<br /> snd_pcm_action_single+0x36/0x90<br /> snd_pcm_action_nonatomic+0xbf/0xd0<br /> snd_pcm_ioctl+0x28/0x40<br /> __x64_sys_ioctl+0x97/0xe0<br /> do_syscall_64+0x81/0x610<br /> entry_SYSCALL_64_after_hwframe+0x76/0x7e<br /> <br /> Revert CT_PTP_NUM to 1. The 256 SRC_RESOURCE_NUM and playback_count<br /> remain unchanged.