{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.1.5-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  ALSA: seq: avoid stale FIFO cells during resize  snd_seq_fifo_resize() still needs to publish the replacement pool before it waits for FIFO users. A blocking snd_seq_read() holds f-\u003euse_lock while it sleeps, so concurrent senders must be able to queue to the new pool and wake that reader instead of failing against a closing old pool.  However, snd_seq_fifo_event_in() duplicates an event before it takes f-\u003elock, and snd_seq_read() can dequeue a cell and later call snd_seq_fifo_cell_putback() if copy_to_user() or snd_seq_expand_var_event() fails. If resize swaps f-\u003epool and detaches oldhead in between, either path can relink an old-pool cell after the snapshot. That stale cell sits outside the drained oldhead list, keeps oldpool-\u003ecounter elevated, and can leave snd_seq_pool_delete() waiting for the retired pool to drain.  Keep the existing swap-before-wait ordering in snd_seq_fifo_resize(), but reject stale cells before any FIFO relink. Revalidate event-in cells under f-\u003elock and retry them against the published replacement pool, and free stale putback cells instead of linking them back into the FIFO.  The buggy scenario involves two paths, with each column showing the order within that path:  resize path:                    relink path: 1. Allocate newpool.             1. Take f-\u003euse_lock. 2. Swap f-\u003epool to newpool and   2. Duplicate or dequeue an old-pool    detach oldhead.                  cell before oldpool closes. 3. Mark oldpool closing and      3. Reach a later relink point after    wait for FIFO users.             resize published newpool. 4. Free oldhead and delete       4. Relink the old-pool cell after    oldpool.                         resize detached oldhead.                                  5. Drop f-\u003euse_lock.  The reproducer reports a resize ioctl blocked in the expected pool teardown path:  signal: resize iteration=98 target_pool=4 exceeded 250ms         (elapsed=251ms) diagnostic: resize_tid=651 wchan=snd_seq_pool_done diagnostic: resize_tid=651 stack=   snd_seq_pool_done+0x5b/0x140   snd_seq_pool_delete+0x7a/0x90   snd_seq_fifo_resize+0x193/0x1e0   snd_seq_ioctl_set_client_pool+0x214/0x260   snd_seq_ioctl+0x119/0x540   __x64_sys_ioctl+0xd1/0x120   do_syscall_64+0xbb/0x2f0   entry_SYSCALL_64_after_hwframe+0x77/0x7f  A second run with larger pools hit the same target path:  signal: resize iteration=32 target_pool=64 exceeded 250ms         (elapsed=251ms) diagnostic: resize_tid=663 wchan=snd_seq_pool_done diagnostic: resize_tid=663 stack=   snd_seq_pool_done+0x5b/0x140   snd_seq_pool_delete+0x7a/0x90   snd_seq_fifo_resize+0x193/0x1e0   snd_seq_ioctl_set_client_pool+0x214/0x260   snd_seq_ioctl+0x119/0x540   __x64_sys_ioctl+0xd1/0x120   do_syscall_64+0xbb/0x2f0   entry_SYSCALL_64_after_hwframe+0x77/0x7f",
  "id": "DEBIAN-CVE-2026-74261",
  "modified": "2026-09-14T16:47:49.050860766Z",
  "published": "2026-08-15T06:22:25.307Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-74261"
    }
  ],
  "upstream": [
    "CVE-2026-74261"
  ]
}