{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "7a0f55aeeb8f1fa32a119d34ddfefc6100936692"
            },
            {
              "fixed": "a84371be89c39ccc46c7af8b9eb15c448df9265f"
            },
            {
              "fixed": "3f75da1e4ee699f6650d23d6897cf443b01856c7"
            },
            {
              "fixed": "b78748424f29f07d310484b2b36afdececa74389"
            },
            {
              "fixed": "61b0a5a114fa4552892da5c0ff2f42e63bf08c6b"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.9.0"
            },
            {
              "fixed": "6.12.113"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.56"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98836.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: line6: reject oversized playback packets\n\nEach playback URB is handed a slice of out.buffer that is exactly\nLINE6_ISO_PACKETS * max_packet_size_out bytes, sized from the OUT\nendpoint, but the number of bytes written into that slice is never\ncompared against it.\n\nsubmit_audio_out_urb() takes the frame count from prev_fsize, which\naudio_in_callback() derived from the *IN* endpoint's received packet\nlength, and rescales it with the playback frame size; when prev_fsize is\nstill zero it synthesizes a length from the sample rate instead.  On a\ndevice declaring a large IN wMaxPacketSize and a small OUT\nwMaxPacketSize, the resulting memcpy(), or the memset() when the\nplayback stream is idle, runs past its slice and, as the reproducer\nbelow shows, beyond the allocation.\n\nusb_submit_urb() is not a backstop.  max_packet_size_out comes from\nusb_maxpacket(), which returns only the low 11 bits of wMaxPacketSize,\nwhile USB core validates a high-speed isochronous length against that\nbase scaled by usb_endpoint_maxp_mult().  A length of up to three times\nthe allocated slice is therefore accepted, and even a rejected URB is\nonly rejected after the write.\n\nReject a packet that does not fit the slice the driver allocated for it.\nClamping it instead would silently shorten the capture-derived rate\nfeedback and desynchronize the two streams.\n\n  BUG: KASAN: slab-out-of-bounds in submit_audio_out_urb (sound/usb/line6/playback.c:229)\n  Write of size 1024 at addr ffff888100bbd400 by task kworker/1:2/5002\n  Workqueue: events line6_startup_work\n  Call Trace:\n   __asan_memcpy (mm/kasan/shadow.c:106)\n   submit_audio_out_urb (sound/usb/line6/playback.c:229)\n   line6_submit_audio_out_all_urbs (sound/usb/line6/playback.c:291)\n   line6_stream_start (sound/usb/line6/pcm.c:194)\n   line6_pcm_acquire (sound/usb/line6/pcm.c:337)\n   line6_startup_work (sound/usb/line6/driver.c:728)\n   process_one_work (kernel/workqueue.c:3396)\n   worker_thread (kernel/workqueue.c:3479 kernel/workqueue.c:3560)\n   kthread (kernel/kthread.c:436)\n   ret_from_fork (arch/x86/kernel/process.c:158)\n   ret_from_fork_asm (arch/x86/entry/entry_64.S:245)\n\n  The buggy address belongs to the object at ffff888100bbd400\n   which belongs to the cache kmalloc-256 of size 256\n  The buggy address is located 0 bytes inside of\n   allocated 256-byte region [ffff888100bbd400, ffff888100bbd500)",
  "id": "CVE-2026-98836",
  "modified": "2026-10-20T02:31:12.283124030Z",
  "published": "2026-10-18T15:49:51.823Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3f75da1e4ee699f6650d23d6897cf443b01856c7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/61b0a5a114fa4552892da5c0ff2f42e63bf08c6b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a84371be89c39ccc46c7af8b9eb15c448df9265f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b78748424f29f07d310484b2b36afdececa74389"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98836.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98836"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "ALSA: line6: reject oversized playback packets"
}