In the Linux kernel, the following vulnerability has been resolved: xsk: fix buffer leak in xsk_drop_skb() for AF_XDP multi-buffer Tx This patch is inspired by the check[1] from sashiko. It says when overflow happens, the address of cq to be published is invalid. Actually the severer thing is the whole process of publishing the address of cq in this particular case is not right: it should truely publish the address and advance the cached_prod in cq as long as it reads descriptors from txq. The following is the full analysis. xsk_drop_skb() is called in three places, which all discard a partially built multi-buffer skb: 1) xsk_build_skb() -EOVERFLOW error path: packet exceeds MAX_SKB_FRAGS 2) __xsk_generic_xmit() post-loop cleanup: an invalid descriptor in the TX ring prevents the partial packet from completing 3) xsk_release(): socket close while xs->skb holds an incomplete packet In all three cases, the TX descriptors for the already-processed frags have been consumed from the TX ring (xskq_cons_release), and CQ slots have been reserved. However, xsk_drop_skb() calls xsk_consume_skb() which cancels the CQ reservations via xsk_cq_cancel_locked(). Since the buffer addresses never appear in the completion queue, userspace permanently loses track of these buffers. Fix this by letting consume_skb() trigger the existing xsk_destruct_skb destructor, which already submits buffer addresses to the CQ via xsk_cq_submit_addr_locked(). Note that cancelling the descriptors back to the TX ring (via xskq_cons_cancel_n) is not a appropriate option because an oversized packet that always exceeds MAX_SKB_FRAGS would be retried indefinitely, which is an obviously deadlock bug in the TX path. Also move the desc->addr assignment in xsk_build_skb() above the overflow check so that the current descriptor's address is recorded before a potential -EOVERFLOW jump to free_err, consistent with the zerocopy path in xsk_build_skb_zerocopy(). [1]: https://lore.kernel.org/all/20260425041726.85FB3C2BCB2@smtp.kernel.org/

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - In the Linux kernel, the following vulnerability has been resolved: xsk: fix buffer leak in xsk_drop_skb()
    for AF_XDP multi-buffer Tx This patch is inspired by the check[1] from sashiko. It says when overflow
    happens, the address of cq to be published is invalid. Actually the severer thing is the whole process of
    publishing the address of cq in this particular case is not right: it should truely publish the address
    and advance the cached_prod in cq as long as it reads descriptors from txq. The following is the full
    analysis. xsk_drop_skb() is called in three places, which all discard a partially built multi-buffer skb:
    1) xsk_build_skb() -EOVERFLOW error path: packet exceeds MAX_SKB_FRAGS 2) __xsk_generic_xmit() post-loop
    cleanup: an invalid descriptor in the TX ring prevents the partial packet from completing 3)
    xsk_release(): socket close while xs->skb holds an incomplete packet In all three cases, the TX
    descriptors for the already-processed frags have been consumed from the TX ring (xskq_cons_release), and
    CQ slots have been reserved. However, xsk_drop_skb() calls xsk_consume_skb() which cancels the CQ
    reservations via xsk_cq_cancel_locked(). Since the buffer addresses never appear in the completion queue,
    userspace permanently loses track of these buffers. Fix this by letting consume_skb() trigger the existing
    xsk_destruct_skb destructor, which already submits buffer addresses to the CQ via
    xsk_cq_submit_addr_locked(). Note that cancelling the descriptors back to the TX ring (via
    xskq_cons_cancel_n) is not a appropriate option because an oversized packet that always exceeds
    MAX_SKB_FRAGS would be retried indefinitely, which is an obviously deadlock bug in the TX path. Also move
    the desc->addr assignment in xsk_build_skb() above the overflow check so that the current descriptor's
    address is recorded before a potential -EOVERFLOW jump to free_err, consistent with the zerocopy path in
    xsk_build_skb_zerocopy(). [1]: https://lore.kernel.org/all/20260425041726.85FB3C2BCB2@smtp.kernel.org/
    (CVE-2026-74560)

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - xsk: fix buffer leak in xsk_drop_skb() for AF_XDP multi-buffer Tx This patch is inspired by the check[1]     from sashiko. It says when overflow happens, the address of cq to be published is invalid. Actually the     severer thing is the whole process of publishing the address of cq in this particular case is not right:
    it should truely publish the address and advance the cached_prod in cq as long as it reads descriptors     from txq. The following is the full analysis. xsk_drop_skb() is called in three places, which all discard     a partially built multi-buffer skb: 1) xsk_build_skb() -EOVERFLOW error path: packet exceeds MAX_SKB_FRAGS     2) __xsk_generic_xmit() post-loop cleanup: an invalid descriptor in the TX ring prevents the partial     packet from completing 3) xsk_release(): socket close while xs->skb holds an incomplete packet In all     three cases, the TX descriptors for the already-processed frags have been consumed from the TX ring     (xskq_cons_release), and CQ slots have been reserved. However, xsk_drop_skb() calls xsk_consume_skb()     which cancels the CQ reservations via xsk_cq_cancel_locked(). Since the buffer addresses never appear in     the completion queue, userspace permanently loses track of these buffers. Fix this by letting     consume_skb() trigger the existing xsk_destruct_skb destructor, which already submits buffer addresses to     the CQ via xsk_cq_submit_addr_locked(). Note that cancelling the descriptors back to the TX ring (via     xskq_cons_cancel_n) is not a appropriate option because an oversized packet that always exceeds     MAX_SKB_FRAGS would be retried indefinitely, which is an obviously deadlock bug in the TX path. Also move     the desc->addr assignment in xsk_build_skb() above the overflow check so that the current descriptor's     address is recorded before a potential -EOVERFLOW jump to free_err, consistent with the zerocopy path in     xsk_build_skb_zerocopy(). [1]: https://lore.kernel.org/all/20260425041726.85FB3C2BCB2@smtp.kernel.org/     (CVE-2026-74560)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
376443	Ubuntu 24.04 LTS / 26.04 LTS : Linux kernel vulnerabilities (USN-8959-1)	Nessus	Ubuntu Local Security Checks	Local	high
471387	Google: sys-kernel/cchost-kernel-6_12, sys-kernel/cchost-kernel-6_18, sys-kernel/csql-kernel-6_12, sys-kernel/csql-kernel-6_18, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-kernel-6_18, sys-kernel/lakitu-nc-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_18: security update to 19999.44.21	Tenable Cloud Security	Google COS Security Checks	Local	medium
471387	Google: sys-kernel/cchost-kernel-6_12, sys-kernel/cchost-kernel-6_18, sys-kernel/csql-kernel-6_12, sys-kernel/csql-kernel-6_18, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-kernel-6_18, sys-kernel/lakitu-nc-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_18: security update to 19999.44.21	Tenable Self-Hosted Container Security	Google COS Security Checks	Local	medium
470687	Google: sys-kernel/cchost-kernel-6_18, sys-kernel/csql-kernel-6_18, sys-kernel/lakitu-kernel-6_18, sys-kernel/lakitu-nc-kernel-6_18: security update to 20085.0.0	Tenable Cloud Security	Google COS Security Checks	Local	medium
470687	Google: sys-kernel/cchost-kernel-6_18, sys-kernel/csql-kernel-6_18, sys-kernel/lakitu-kernel-6_18, sys-kernel/lakitu-nc-kernel-6_18: security update to 20085.0.0	Tenable Self-Hosted Container Security	Google COS Security Checks	Local	medium
341888	Amazon Linux 2023 : bpftool6.18, kernel6.18, kernel6.18-devel (ALAS2023-2026-2106)	Nessus	Amazon Linux Local Security Checks	Local	high
335832	Linux Distros Unpatched Vulnerability : CVE-2026-74560	Nessus	Misc.	Local	medium

Detections

Analytics

CVE-2026-74560

high

Tenable Plugins

high

medium

medium

medium

medium

high

medium