# CVE-2026-98947: vsock: Fix memory leak in vmci_transport_recv_dgram_cb()


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** AZL-110750, BELL-CVE-2026-98947, DEBIAN-CVE-2026-98947, GHSA-cf52-4qc8-h2h9, UBUNTU-CVE-2026-98947

## What is CVE-2026-98947?

CVE-2026-98947 is a vulnerability in Linux, published on 23 Oct 2026. 

### Official description

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

vsock: Fix memory leak in vmci_transport_recv_dgram_cb()

During the closure of a datagram socket, the vmci_transport_recv_dgram_cb()
function may be called, which will add the packets
to the socket's backlog; then, after the receive queue is cleared,
the __release_sock() function will move the packet back from the socket's
backlog to the receive queue, which will lead to a memory leak.

sock_close
  __sock_release
    __vsock_release
      // take ownership by user-space
      lock_sock_nested
      sock_set_flag(sk, SOCK_DEAD)
      vmci_transport_release
                                      vmci_dispatch_dgs
                                        vmci_datagram_invoke_guest_handler
                                          vmci_transport_recv_dgram_cb
                                            sk_receive_skb
                                              if (!sock_owned_by_user(sk))
                                                  [...]
                                         (!)  else if sk_add_backlog()
                                                  [...]
  (!) skb_queue_purge(&sk->sk_receive_queue)

      release_sock
        __release_sock
          // move all packets from the backlog
          // to the receive queue
   (!)    sk_backlog_rcv
            vsock_queue_rcv_skb
            [...]
              __sock_queue_rcv_skb
                if (!sock_flag(sk, SOCK_DEAD))
                  // Since the socket is "dead", the function will not
                  // be called
                  sk->sk_data_ready(sk)
        sock_release_ownership(sk);
        sock_put

Add a receive queue cleanup in the socket destructor to fix this.

syzkaller report:

unreferenced object 0xffff8880117bfb80 (size 240):
  comm "irq/56-vmw_vmci", pid 205, jiffies 4295064448 (age 73.992s)
  hex dump (first 32 bytes):
    78 dc 26 1e 80 88 ff ff 78 dc 26 1e 80 88 ff ff  x.&.....x.&.....
    00 00 00 00 00 00 00 00 c0 da 26 1e 80 88 ff ff  ..........&.....
  backtrace:
    [<ffffffff82be8d97>] __alloc_skb+0x287/0x330 net/core/skbuff.c:505
    [<ffffffffa114bcbd>] vmci_transport_recv_dgram_cb+0xbd/0x210 [vmw_vsock_vmci_transport]
    [<ffffffffa05072c6>] vmci_datagram_invoke_guest_handler+0x366/0x450 [vmw_vmci]
    [<ffffffffa050ad75>] vmci_dispatch_dgs+0x235/0x490 [vmw_vmci]
    [<ffffffffa050b025>] vmci_interrupt+0x55/0x290 [vmw_vmci]
    [<ffffffff8137ad2b>] irq_thread_fn+0x8b/0x1a0 kernel/irq/manage.c:1205
    [<ffffffff8137c7ae>] irq_thread+0x28e/0x530 kernel/irq/manage.c:1314
    [<ffffffff81253dd6>] kthread+0x2e6/0x3a0 kernel/kthread.c:376
    [<ffffffff81004392>] ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:295

Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with Syzkaller.

## Which versions are affected by CVE-2026-98947?


## How do I fix CVE-2026-98947?

Upgrade to a fixed version.

## Is CVE-2026-98947 being exploited?

There is no known exploitation of CVE-2026-98947 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98947 and fix it if it is affected.

What it is: CVE-2026-98947 is a vulnerability in Linux, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-98947 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-98947/ (Markdown: https://insights.sbomify.com/CVE-2026-98947/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98947
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98947
- OSV: https://osv.dev/vulnerability/CVE-2026-98947

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98947/
Summaries are generated and may contain mistakes; the official description above is the record.