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CVE-2026-98741 json

ALSA: ua101: reject mismatched capture/playback packet sizes

published 24d ago modified 12d ago also EUVD-2026-103826

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

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

ALSA: ua101: reject mismatched capture/playback packet sizes

detect_usb_format() cross-checks bSubframeSize, bBitResolution and tSamFreq between the capture and playback interfaces, but never relates the two endpoints' wMaxPacketSize and bNrChannels. Each playback URB gets a buffer of ua->playback.max_packet_bytes, while the number of bytes written into it is derived from the capture stream: capture_urb_complete() computes frames from the received capture packet and capture.frame_bytes, and start_usb_playback() and playback_work() multiply that by playback.frame_bytes.

A device declaring a large capture wMaxPacketSize with few capture channels and a small playback wMaxPacketSize with many playback channels therefore memset()s and memcpy()s past the end of the playback buffer, in open() of the PCM node the driver registers during probe. usb_submit_urb() rejects the over-long iso_frame_desc[0].length with -EMSGSIZE, but only after the write.

Reject such descriptors at probe time. Genuine UA-101/UA-1000 hardware declares proportional packet sizes and is unaffected.

BUG: KASAN: slab-out-of-bounds in start_usb_playback (sound/usb/misc/ua101.c:586) Write of size 2048 at addr ffff8881098f3c00 by task exploit/5021 Call Trace: __asan_memset (mm/kasan/shadow.c:84) start_usb_playback (sound/usb/misc/ua101.c:586) playback_pcm_open (sound/usb/misc/ua101.c:679) snd_pcm_open_substream (sound/core/pcm_native.c:2829) snd_pcm_open (sound/core/pcm_native.c:2865 sound/core/pcm_native.c:2932) snd_pcm_playback_open (sound/core/pcm_native.c:2891) snd_open (sound/core/sound.c:166) chrdev_open (fs/char_dev.c:411) do_dentry_open (fs/open.c:996) vfs_open (fs/open.c:1101) path_openat (fs/namei.c:4837 fs/namei.c:5000) do_file_open (fs/namei.c:5029) do_sys_openat2 (fs/open.c:1417) __x64_sys_openat (fs/open.c:1423 fs/open.c:1439 fs/open.c:1434) do_syscall_64 (arch/x86/entry/syscall_64.c:61 arch/x86/entry/syscall_64.c:84) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)

The buggy address belongs to the object at ffff8881098f3c00 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 0 bytes inside of allocated 168-byte region [ffff8881098f3c00, ffff8881098f3ca8)

Patch / fix

  • Linux Linux 7.3
  • linux Debian 13 6.12.113-1
  • linux Debian 14 7.2.10-1
  • linux-6.12 Debian 12 6.12.113-1~deb12u1

debian advisories DEBIAN-CVE-2026-98741

  • linux Ubuntu 24.04 LTS 6.8.0-149.149
  • linux Ubuntu 26.04 LTS 7.0.0-43.43
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1069.74
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1017.18
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1073.81
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1017.19
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1068.77
  • linux-gke Ubuntu 26.04 LTS 7.0.0-1010.11

ubuntu advisories UBUNTU-CVE-2026-98741

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-source Linux Micro 6.0 6.4.0-159998.55.1
  • kernel-default Linux Micro 6.0 6.4.0-159998.55.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-159998.55.1
  • kernel-default-base Linux Micro 6.0 6.4.0-159998.55.1.159998.21.42
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.90.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.90.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.90.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.90.1

suse advisories SUSE-SU-2026:24550-1SUSE-SU-2026:5091-1

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-98741 updated cvss 7.8

kernel: ALSA: ua101: reject mismatched capture/playback packet sizes

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more Red Hat Enterprise Linux 10 kernel Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    +1 more products
    Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: no fix available
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-741.22.1.el9_9, perf 5.14.0-741.22.1.el9_9, rtla 5.14.0-741.22.1.el9_9, python3-perf 5.14.0-741.22.1.el9_9, kernel-devel-matched 5.14.0-741.22.1.el9_9, kernel-64k-devel-matched 5.14.0-741.22.1.el9_9, +7 more Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-741.22.1.el9_9, kernel-64k 5.14.0-741.22.1.el9_9, kernel-core 5.14.0-741.22.1.el9_9, kernel-tools 5.14.0-741.22.1.el9_9, kernel-modules 5.14.0-741.22.1.el9_9, kernel-64k-core 5.14.0-741.22.1.el9_9, +27 more Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-741.22.1.el9_9, kernel-debuginfo-common-s390x 5.14.0-741.22.1.el9_9, kernel-debuginfo-common-x86_64 5.14.0-741.22.1.el9_9, kernel-debuginfo-common-aarch64 5.14.0-741.22.1.el9_9, kernel-debuginfo-common-ppc64le 5.14.0-741.22.1.el9_9 Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-741.22.1.el9_9, kernel-rt-64k 5.14.0-741.22.1.el9_9, kernel-rt-core 5.14.0-741.22.1.el9_9, kernel-rt-modules 5.14.0-741.22.1.el9_9, kernel-rt-64k-core 5.14.0-741.22.1.el9_9, kernel-rt-debug-core 5.14.0-741.22.1.el9_9, +14 more Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-741.22.1.el9_9, kernel-rt-core 5.14.0-741.22.1.el9_9, kernel-rt-modules 5.14.0-741.22.1.el9_9, kernel-rt-debug-core 5.14.0-741.22.1.el9_9, kernel-rt-modules-core 5.14.0-741.22.1.el9_9, kernel-rt-debug-modules 5.14.0-741.22.1.el9_9, +5 more
    fixed: vendor fix RHSA-2026:99135

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-11).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

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