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CVE-2026-74543

N/A ALL-YEARS

Published 2026-08-15 · Last modified 2026-10-21 · Linux · NVD: Received

In the Linux kernel, the following vulnerability has been resolved: net: udp_tunnel: fix memory leak in udp_tunnel_nic_unregister() syzbot reported a memory leak [1] in the UDP tunnel NIC offload code. When device registration fails (e.g. in register_netdevice()), netdev core unwinds by sending a single NETDEV_UNREGISTER notification. If work was queued during NETDEV_REGISTER (utn->work_pending is set), udp_tunnel_nic_unregister() returns early: if (utn->work_pending) return; Because failed registrations do not enter netdev_wait_allrefs_any(), no subsequent NETDEV_UNREGISTER rebroadcast will ever occur. As a result, the struct udp_tunnel_nic allocated in udp_tunnel_nic_alloc() is leaked permanently. Fix this by removing the early return. Instead, synchronously cancel any pending work with cancel_delayed_work_sync() before freeing @utn. To be able to call cancel_delayed_work_sync() while holding RTNL (the work also needs RTNL), switch udp_tunnel_nic_device_sync_work() to rtnl_trylock(). If RTNL is contended, requeue the work with a 1 jiffy delay (via queue_delayed_work()) to prevent high CPU contention while waiting for RTNL lock. The utn->work_pending bookkeeping is no longer needed and is removed, as the workqueue core already tracks the pending/running state of the work. [1] BUG: memory leak unreferenced object 0xffff888127d5f840 (size 96): comm "syz-executor", pid 5806, jiffies 4294942188 backtrace (crc 99fdb6c8): __kmalloc_noprof+0x3bf/0x550 udp_tu

LIMITED SIGNALS

No known exploitation, public exploit, or elevated probability at this time. Track for changes.

Exploitation likelihood

0.2%chance of exploitation in 30 days · 7th percentile

○ In CISA KEV○ Catalogued PoC

Impact if exploited

—CVSS · not scored

  • No impact metrics

Proof of concept

No public PoC is currently catalogued.

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Affected

Vendors Linux

Products Linux

Weakness (CWE)

Not classified.

CVSS vector

Not yet scored.

References and research data (JSON)

Vendor product assessments

Showing 32 of 275 vendor product statements; 243 omitted. Read the full vendor advisory.

  • kernel as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-abi-stablelists as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-abi-stablelists

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-modules-extra-matched as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-modules-extra-matched

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-rt-core as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-rt-core

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-uki-virt as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-uki-virt

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • bpftool as a component of Red Hat Enterprise Linux 8 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/bpftool

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-modules as a component of Red Hat Enterprise Linux 8 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-modules

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-rt-modules-extra as a component of Red Hat Enterprise Linux 8 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-rt-modules-extra

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • python3-perf as a component of Red Hat Enterprise Linux 8 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/python3-perf

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-64k-devel-matched as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-64k-devel-matched

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-debug-modules-internal as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-debug-modules-internal

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-rt-64k as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-rt-64k

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-rt-64k-modules-core as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-rt-64k-modules-core

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-rt-devel as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-rt-devel

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-zfcpdump as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/kernel-zfcpdump

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • rv as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/rv

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Fix deferred
    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel as a component of Red Hat Enterprise Linux 6 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-debug as a component of Red Hat Enterprise Linux 6 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-debug

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-devel as a component of Red Hat Enterprise Linux 6 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-devel

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-headers as a component of Red Hat Enterprise Linux 6 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-headers

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel.src as a component of Red Hat Enterprise Linux 6 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel?arch=src

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • bpftool as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/bpftool

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-abi-whitelists as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-abi-whitelists

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-debug-devel as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-debug-devel

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-headers as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-headers

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-rt as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-rt-debug-devel as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-debug-devel

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-rt-doc as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-doc

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-rt-trace-devel as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-rt-trace-devel

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-tools as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-tools

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • kernel-tools-libs-devel as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/kernel-tools-libs-devel

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00
  • python-perf as a component of Red Hat Enterprise Linux 7 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/python-perf

    Red Hat · CVE-2026-74543 · Updated 2026-10-17T21:44:20+00:00

References

Advisories

Technical & other

Sources: NVD · CVE.org · All sources and attribution · EPSS