0.0
NA
CVE-2026-80841
net/packet: defer vmalloc TX_RING free until skbs finish
Description

In the Linux kernel, the following vulnerability has been resolved: net/packet: defer vmalloc TX_RING free until skbs finish AF_PACKET TX_RING skbs keep a raw pointer to their ring frame. The skb page references preserve page-backed ring blocks after pg_vec is freed, but they do not preserve a vmalloc mapping. tpacket_destruct_skb() currently drops the pending reference before writing the timestamp and TP_STATUS_AVAILABLE to the frame. Move the decrement after those stores. The smp_wmb() in __packet_set_status() orders the frame stores before the decrement. Also recheck pending TX frames under pg_vec_lock before non-closing ring replacement, so a racing send cannot add a pending skb between the initial check and the ring swap. Ring allocation can produce a mixture of page-backed and vmalloc-backed blocks. Allocate deferred-work storage during TX ring setup when the first vmalloc-backed block is encountered, and keep its pointer in the pg_vec allocation header. If allocation fails, return -ENOMEM from ring setup. On socket close, a non-NULL pointer identifies a vmalloc-backed vector without a scan. If TX skbs remain, defer the whole vector to system_long_wq. After pg_vec is detached, a late destructor can skip the pending decrement. Use socket write-memory accounting as the deferred lifetime gate instead: an skb remains charged through its final sock_wfree(), after all ring-frame accesses. The delayed work retains a socket reference and reschedules itself until no TX skbs remain. Move pending_refcnt release to packet_sock_destruct() so late skb destructors and deferred cleanup can safely use it after packet_release(). Page-backed teardown remains synchronous, and no lock is added to the TX completion hot path.

INFO

Published Date :

Sept. 4, 2026, 4:18 p.m.

Last Modified :

Sept. 4, 2026, 4:18 p.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products

The following products are affected by CVE-2026-80841 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

Solution
Update the Linux kernel to fix memory management issues in AF_PACKET TX_RING.
  • Apply kernel patches to address AF_PACKET TX_RING vulnerability.
  • Update the Linux kernel to the latest stable version.
  • Verify kernel updates include the resolved TX_RING issue.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-80841.

URL Resource
https://git.kernel.org/stable/c/0189dce07db2dc059ae0570e06758ec4233c6e11
https://git.kernel.org/stable/c/550d00aa58193fb649a09a9c9e338c685adad784
https://git.kernel.org/stable/c/992cc9f94ca924089a506ba9b327caa9af797529
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-80841 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-80841 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-80841 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-80841 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Sep. 04, 2026

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: net/packet: defer vmalloc TX_RING free until skbs finish AF_PACKET TX_RING skbs keep a raw pointer to their ring frame. The skb page references preserve page-backed ring blocks after pg_vec is freed, but they do not preserve a vmalloc mapping. tpacket_destruct_skb() currently drops the pending reference before writing the timestamp and TP_STATUS_AVAILABLE to the frame. Move the decrement after those stores. The smp_wmb() in __packet_set_status() orders the frame stores before the decrement. Also recheck pending TX frames under pg_vec_lock before non-closing ring replacement, so a racing send cannot add a pending skb between the initial check and the ring swap. Ring allocation can produce a mixture of page-backed and vmalloc-backed blocks. Allocate deferred-work storage during TX ring setup when the first vmalloc-backed block is encountered, and keep its pointer in the pg_vec allocation header. If allocation fails, return -ENOMEM from ring setup. On socket close, a non-NULL pointer identifies a vmalloc-backed vector without a scan. If TX skbs remain, defer the whole vector to system_long_wq. After pg_vec is detached, a late destructor can skip the pending decrement. Use socket write-memory accounting as the deferred lifetime gate instead: an skb remains charged through its final sock_wfree(), after all ring-frame accesses. The delayed work retains a socket reference and reschedules itself until no TX skbs remain. Move pending_refcnt release to packet_sock_destruct() so late skb destructors and deferred cleanup can safely use it after packet_release(). Page-backed teardown remains synchronous, and no lock is added to the TX completion hot path.
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80841.json">CVE-2026-80841</a>
    Added Reference https://git.kernel.org/stable/c/0189dce07db2dc059ae0570e06758ec4233c6e11
    Added Reference https://git.kernel.org/stable/c/550d00aa58193fb649a09a9c9e338c685adad784
    Added Reference https://git.kernel.org/stable/c/992cc9f94ca924089a506ba9b327caa9af797529
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.