CVE-2026-31602
HighIn the Linux kernel, the following vulnerability has been resolved: ALSA: ctxfi: Limit PTP to a single page Commit 391e69143d0a increased CT_PTP_NUM from 1 to 4 to support 256 playback streams, but the additional pages are not used by the card correctly. The CT20K2 hardware already has multiple VMEM_PTPAL registers, but using them separately would require refactoring the entire virtual memory allocation logic. ct_vm_map() always uses PTEs in vm->ptp[0].area regardless of CT_PTP_NUM. On AMD64 systems, a single PTP covers 512 PTEs (2M). When aggregate memory allocations exceed this limit, ct_vm_map() tries to access beyond the allocated space and causes a page fault: BUG: unable to handle page fault for address: ffffd4ae8a10a000 Oops: Oops: 0002 [#1] SMP PTI RIP: 0010:ct_vm_map+0x17c/0x280 [snd_ctxfi] Call Trace: atc_pcm_playback_prepare+0x225/0x3b0 ct_pcm_playback_prepare+0x38/0x60 snd_pcm_do_prepare+0x2f/0x50 snd_pcm_action_single+0x36/0x90 snd_pcm_action_nonatomic+0xbf/0xd0 snd_pcm_ioctl+0x28/0x40 __x64_sys_ioctl+0x97/0xe0 do_syscall_64+0x81/0x610 entry_SYSCALL_64_after_hwframe+0x76/0x7e Revert CT_PTP_NUM to 1. The 256 SRC_RESOURCE_NUM and playback_count remain unchanged.
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected versions
Linux kernel versions
3.2
and later are affected. Fixed in
5.10.258,
5.15.209,
6.1.175,
6.6.136,
6.12.83,
6.18.24,
6.19.14,
7.0.1,
7.1-rc1
and their respective stable series.
References
The following references provide additional information about CVE-2026-31602 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/2b4331c08c0b385598b4d8ccd71e93ab3f4b2578
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PatchKernel patch commithttps://git.kernel.org/stable/c/365c36e1a126c6aa1aecedd3a351bcabc66f0c29
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PatchKernel patch commithttps://git.kernel.org/stable/c/3fd0685d7fef68c2d8a04876bcf9eaa0724ad6a5
Frequently asked questions
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What is CVE-2026-31602?
CVE-2026-31602 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 3.2 onward and has been patched in 5.10.258, 5.15.209, 6.1.175 and others. CVE-2026-31602 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-31602?
CVE-2026-31602 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2026-31602?
Yes — CVE-2026-31602 has been patched. Fixed versions include 5.10.258, 5.15.209, 6.1.175 and others. If you are running Linux kernel 3.2 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-31602 actively exploited?
No — CVE-2026-31602 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.