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CVE-2026-97931

ALSA: us122l: Prevent write upgrades for read mappings

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, and 2 more
None on Exploit-DB, Metasploit or GitHub

Summary

In the Linux kernel, the following vulnerability has been resolved: ALSA: us122l: Prevent write upgrades for read mappings The hwdep mmap callback rejects read-buffer mappings that are initially writable, but leaves VM_MAYWRITE set on mappings created with PROT_READ. A process that can open the hwdep node O_RDWR can later use mprotect() to make the mapping writable. The read allocation begins with struct usb_stream. Its read_size member is used by the fault handler to decide which pages belong to the read buffer. The read VMA intentionally remains expandable because pcm_usb_stream uses mremap() after reading that size. Changing read_size first can therefore map and access pages beyond the allocation. The same member is also consumed by usb_stream_free(), where changing it can make free_pages_exact() release pages outside the allocation. Clear VM_MAYWRITE for read-buffer mappings after rejecting an initially writable VMA. This keeps the separate output-buffer mapping writable while preventing later permission upgrades.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From 030a07e441296c372f946cd4065b5d831d8dc40c · fixed in cbc1f954ce67d739d41d1f0757d29850353ebb6a; From 030a07e441296c372f946cd4065b5d831d8dc40c · fixed in becb89036a1320ef0a77da2d27935ac0704345c4; From 030a07e441296c372f946cd4065b5d831d8dc40c · fixed in 6a5f5a5a32c78e67701f1d0f26bc87af68895604; From 030a07e441296c372f946cd4065b5d831d8dc40c · fixed in 938e8d6cee8d36f24669dfdcd3717e081eb32d64; From 030a07e441296c372f946cd4065b5d831d8dc40c · fixed in 64a87950239867682cde128020e1a47088295e5c; From 030a07e441296c372f946cd4065b5d831d8dc40c · fixed in d9c537b14f4982f17b103e3a2cfeee4bee6bc026; From 030a07e441296c372f946cd4065b5d831d8dc40c · fixed in 0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f; From 030a07e441296c372f946cd4065b5d831d8dc40c · fixed in 71c610aeb1770302ac9c9e0b9a4ecd37f1311928

  • Linux Linux

    2.6.28

  • KernelLinux

    From 2.6.28 · fixed in 5.10.271; From 5.11.0 · fixed in 5.15.222; From 5.16.0 · fixed in 6.1.189; From 6.2.0 · fixed in 6.6.158; From 6.7.0 · fixed in 6.12.111; From 6.13.0 · fixed in 6.18.53; From 6.19.0 · fixed in 7.2.7

References 8

git.kernel.org