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ALSA: ua101: reject mismatched capture/playback packet sizes

Type: advisorySource: Official CVE List1 source record

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_

Announced Source revision 1
Original source ↗

CVE-2026-98741

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-98741

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
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Prerequisites
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Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "63978ab3e3e963db28093b53bb4598f2702e1ad7",
        "lessThan": "ada5ded765f059a6e3036e69ca350449442af0fc",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "63978ab3e3e963db28093b53bb4598f2702e1ad7",
        "lessThan": "fd3a7bf0d988b0878a1957df150edb35f81db87e",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "63978ab3e3e963db28093b53bb4598f2702e1ad7",
        "lessThan": "eb0c7fda59cf650076f8ed5b949a6c8441aa3606",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "63978ab3e3e963db28093b53bb4598f2702e1ad7",
        "lessThan": "4294fe57048594a9e158b61c967bb7f943cda477",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "63978ab3e3e963db28093b53bb4598f2702e1ad7",
        "lessThan": "86f86e6fdedc33c5b8d38b9208b350f8accf57ee",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "sound/usb/misc/ua101.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "2.6.34"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "2.6.34",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.6.160",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.113",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.56",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.10",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "sound/usb/misc/ua101.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-98741

Source reference: /cveMetadata/cveId

Publisher severity

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Event
#48939 · Revision 1
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Publisher date
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