In the Linux kernel, the following vulnerability has been resolved: net: dsa: properly keep track of conduit reference Problem description ------------------- DSA has a mumbo-jumbo of reference handling of the conduit net device and its kobject which, sadly, is just wrong and doesn't make sense. There are two distinct problems. 1. The OF path, which uses of_find_net_device_by_node(), never releases the elevated refcount on the conduit's kobject. Nominally, the OF and non-OF paths should result in objects having identical reference counts taken, and it is already suspicious that dsa_dev_to_net_device() has a put_device() call which is missing in dsa_port_parse_of(), but we can actually even verify that an issue exists. With CONFIG_DEBUG_KOBJECT_RELEASE=y, if we run this command "before" and "after" applying this patch: (unbind the conduit driver for net device eno2) echo 0000:00:00.2 > /sys/bus/pci/drivers/fsl_enetc/unbind we see these lines in the output diff which appear only with the patch applied: kobject: 'eno2' (ffff002009a3a6b8): kobject_release, parent 0000000000000000 (delayed 1000) kobject: '109' (ffff0020099d59a0): kobject_release, parent 0000000000000000 (delayed 1000) 2. After we find the conduit interface one way (OF) or another (non-OF), it can get unregistered at any time, and DSA remains with a long-lived, but in this case stale, cpu_dp->conduit pointer. Holding the net device's underlying kobject isn't actually of much help, it just prevents it from being freed (but we never need that kobject directly). What helps us to prevent the net device from being unregistered is the parallel netdev reference mechanism (dev_hold() and dev_put()). Actually we actually use that netdev tracker mechanism implicitly on user ports since commit 2f1e8ea726e9 ("net: dsa: link interfaces with the DSA master to get rid of lockdep warnings"), via netdev_upper_dev_link(). But time still passes at DSA switch probe time between the initial of_find_net_device_by_node() code and the user port creation time, time during which the conduit could unregister itself and DSA wouldn't know about it. So we have to run of_find_net_device_by_node() under rtnl_lock() to prevent that from happening, and release the lock only with the netdev tracker having acquired the reference. Do we need to keep the reference until dsa_unregister_switch() / dsa_switch_shutdown()? 1: Maybe yes. A switch device will still be registered even if all user ports failed to probe, see commit 86f8b1c01a0a ("net: dsa: Do not make user port errors fatal"), and the cpu_dp->conduit pointers remain valid. I haven't audited all call paths to see whether they will actually use the conduit in lack of any user port, but if they do, it seems safer to not rely on user ports for that reference. 2. Definitely yes. We support changing the conduit which a user port is associated to, and we can get into a situation where we've moved all user ports away from a conduit, thus no longer hold any reference to it via the net device tracker. But we shouldn't let it go nonetheless - see the next change in relation to dsa_tree_find_first_conduit() and LAG conduits which disappear. We have to be prepared to return to the physical conduit, so the CPU port must explicitly keep another reference to it. This is also to say: the user ports and their CPU ports may not always keep a reference to the same conduit net device, and both are needed. As for the conduit's kobject for the /sys/class/net/ entry, we don't care about it, we can release it as soon as we hold the net device object itself. History and blame attribution ----------------------------- The code has been refactored so many times, it is very difficult to follow and properly attribute a blame, but I'll try to make a short history which I hope to be correct. We have two distinct probing paths: - one for OF, introduced in 2016 i ---truncated---

The remote Ubuntu 25.10 / Pro Realtime 24.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-8277-1 advisory.

    It was discovered that the Linux kernel algif_aead module did not properly handle in-place cryptographic     operations. This flaw is known as Copy Fail. A local attacker could use this to escalate privileges, or     possibly escape a container. (CVE-2026-31431)

    Several security issues were discovered in the Linux kernel. An attacker could possibly use these to     compromise the system. This update corrects flaws in the following subsystems:

    - S390 architecture;

    - Cryptographic API;

    - GPU drivers;

    - Ethernet bonding driver;

    - Network file system (NFS) server daemon;

    - Distributed Switch Architecture;

    - Netfilter;

    - Control group (cgroup);

    - Kernel kexec() syscall;

    - Memory management;

    - MAC80211 subsystem;

    - Multipath TCP;

    - Packet sockets;

    - TLS protocol;

    - Unix domain sockets; (CVE-2025-71088, CVE-2025-71090, CVE-2025-71127, CVE-2025-71134, CVE-2025-71139,     CVE-2025-71141, CVE-2025-71142, CVE-2025-71144, CVE-2025-71152, CVE-2025-71155, CVE-2026-23274,     CVE-2026-23351, CVE-2026-23394, CVE-2026-31419, CVE-2026-31504, CVE-2026-31533, CVE-2026-43033,     CVE-2026-43077, CVE-2026-43078)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6238 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6238-1                   security@debian.org     https://www.debian.org/security/                     Salvatore Bonaccorso     April 30, 2026                        https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : linux     CVE ID         : CVE-2024-14027 CVE-2025-21709 CVE-2025-22116 CVE-2025-22117                      CVE-2025-38426 CVE-2025-38627 CVE-2025-39764 CVE-2025-40005                      CVE-2025-40135 CVE-2025-40147 CVE-2025-40150 CVE-2025-40219                      CVE-2025-68175 CVE-2025-68239 CVE-2025-68334 CVE-2025-68736                      CVE-2025-71152 CVE-2025-71161 CVE-2025-71221 CVE-2025-71239                      CVE-2025-71265 CVE-2025-71266 CVE-2025-71267 CVE-2025-71269                      CVE-2026-22981 CVE-2026-22985 CVE-2026-22986 CVE-2026-22993                      CVE-2026-23004 CVE-2026-23066 CVE-2026-23070 CVE-2026-23104                      CVE-2026-23138 CVE-2026-23157 CVE-2026-23207 CVE-2026-23210                      CVE-2026-23226 CVE-2026-23227 CVE-2026-23231 CVE-2026-23239                      CVE-2026-23240 CVE-2026-23242 CVE-2026-23243 CVE-2026-23244                      CVE-2026-23245 CVE-2026-23246 CVE-2026-23249 CVE-2026-23250                      CVE-2026-23251 CVE-2026-23252 CVE-2026-23253 CVE-2026-23255                      CVE-2026-23270 CVE-2026-23271 CVE-2026-23273 CVE-2026-23274                      CVE-2026-23276 CVE-2026-23277 CVE-2026-23278 CVE-2026-23279                      CVE-2026-23281 CVE-2026-23284 CVE-2026-23285 CVE-2026-23286                      CVE-2026-23287 CVE-2026-23289 CVE-2026-23290 CVE-2026-23291                      CVE-2026-23292 CVE-2026-23293 CVE-2026-23296 CVE-2026-23297                      CVE-2026-23298 CVE-2026-23300 CVE-2026-23302 CVE-2026-23303                      CVE-2026-23304 CVE-2026-23306 CVE-2026-23307 CVE-2026-23308                      CVE-2026-23310 CVE-2026-23312 CVE-2026-23313 CVE-2026-23315                      CVE-2026-23316 CVE-2026-23317 CVE-2026-23318 CVE-2026-23319                      CVE-2026-23321 CVE-2026-23324 CVE-2026-23325 CVE-2026-23330                      CVE-2026-23334 CVE-2026-23335 CVE-2026-23336 CVE-2026-23339                      CVE-2026-23340 CVE-2026-23343 CVE-2026-23347 CVE-2026-23351                      CVE-2026-23352 CVE-2026-23354 CVE-2026-23356 CVE-2026-23357                      CVE-2026-23359 CVE-2026-23360 CVE-2026-23361 CVE-2026-23362                      CVE-2026-23363 CVE-2026-23364 CVE-2026-23365 CVE-2026-23367                      CVE-2026-23368 CVE-2026-23369 CVE-2026-23370 CVE-2026-23372                      CVE-2026-23373 CVE-2026-23374 CVE-2026-23375 CVE-2026-23378                      CVE-2026-23379 CVE-2026-23380 CVE-2026-23381 CVE-2026-23382                      CVE-2026-23383 CVE-2026-23386 CVE-2026-23387 CVE-2026-23388                      CVE-2026-23389 CVE-2026-23391 CVE-2026-23392 CVE-2026-23393                      CVE-2026-23395 CVE-2026-23396 CVE-2026-23397 CVE-2026-23398                      CVE-2026-23399 CVE-2026-23401 CVE-2026-23412 CVE-2026-23413                      CVE-2026-23414 CVE-2026-23417 CVE-2026-23419 CVE-2026-23420                      CVE-2026-23422 CVE-2026-23426 CVE-2026-23427 CVE-2026-23428                      CVE-2026-23434 CVE-2026-23438 CVE-2026-23439 CVE-2026-23440                      CVE-2026-23441 CVE-2026-23442 CVE-2026-23444 CVE-2026-23445                      CVE-2026-23446 CVE-2026-23447 CVE-2026-23448 CVE-2026-23449                      CVE-2026-23450 CVE-2026-23452 CVE-2026-23454 CVE-2026-23455                      CVE-2026-23456 CVE-2026-23457 CVE-2026-23458 CVE-2026-23460                      CVE-2026-23461 CVE-2026-23462 CVE-2026-23463 CVE-2026-23464                      CVE-2026-23465 CVE-2026-23466 CVE-2026-23470 CVE-2026-23474                      CVE-2026-23475 CVE-2026-31389 CVE-2026-31391 CVE-2026-31392                      CVE-2026-31393 CVE-2026-31394 CVE-2026-31396 CVE-2026-31399                      CVE-2026-31400 CVE-2026-31401 CVE-2026-31402 CVE-2026-31403                      CVE-2026-31405 CVE-2026-31406 CVE-2026-31407 CVE-2026-31408                      CVE-2026-31409 CVE-2026-31410 CVE-2026-31411 CVE-2026-31412                      CVE-2026-31414 CVE-2026-31415 CVE-2026-31416 CVE-2026-31417                      CVE-2026-31418 CVE-2026-31421 CVE-2026-31422 CVE-2026-31423                      CVE-2026-31424 CVE-2026-31425 CVE-2026-31426 CVE-2026-31427                      CVE-2026-31428 CVE-2026-31429 CVE-2026-31430 CVE-2026-31431                      CVE-2026-31432 CVE-2026-31433 CVE-2026-31434 CVE-2026-31436                      CVE-2026-31438 CVE-2026-31439 CVE-2026-31440 CVE-2026-31441                      CVE-2026-31446 CVE-2026-31447 CVE-2026-31448 CVE-2026-31449                      CVE-2026-31450 CVE-2026-31451 CVE-2026-31452 CVE-2026-31453                      CVE-2026-31454 CVE-2026-31455 CVE-2026-31458 CVE-2026-31462                      CVE-2026-31464 CVE-2026-31466 CVE-2026-31467 CVE-2026-31469                      CVE-2026-31470 CVE-2026-31473 CVE-2026-31474 CVE-2026-31476                      CVE-2026-31477 CVE-2026-31478 CVE-2026-31479 CVE-2026-31480                      CVE-2026-31482 CVE-2026-31483 CVE-2026-31485 CVE-2026-31487                      CVE-2026-31488 CVE-2026-31489 CVE-2026-31492 CVE-2026-31494                      CVE-2026-31495 CVE-2026-31496 CVE-2026-31497 CVE-2026-31498                      CVE-2026-31500 CVE-2026-31502 CVE-2026-31503 CVE-2026-31504                      CVE-2026-31505 CVE-2026-31506 CVE-2026-31507 CVE-2026-31508                      CVE-2026-31509 CVE-2026-31510 CVE-2026-31511 CVE-2026-31512                      CVE-2026-31515 CVE-2026-31516 CVE-2026-31518 CVE-2026-31519                      CVE-2026-31520 CVE-2026-31521 CVE-2026-31522 CVE-2026-31523                      CVE-2026-31524 CVE-2026-31525 CVE-2026-31527 CVE-2026-31528                      CVE-2026-31530 CVE-2026-31531 CVE-2026-31532 CVE-2026-31533                      CVE-2026-31540 CVE-2026-31542 CVE-2026-31545 CVE-2026-31546                      CVE-2026-31548 CVE-2026-31549 CVE-2026-31550 CVE-2026-31551                      CVE-2026-31552 CVE-2026-31554 CVE-2026-31555 CVE-2026-31556                      CVE-2026-31557 CVE-2026-31558 CVE-2026-31559 CVE-2026-31561                      CVE-2026-31563 CVE-2026-31565 CVE-2026-31566 CVE-2026-31570                      CVE-2026-31575 CVE-2026-31576 CVE-2026-31577 CVE-2026-31578                      CVE-2026-31580 CVE-2026-31581 CVE-2026-31582 CVE-2026-31583                      CVE-2026-31584 CVE-2026-31585 CVE-2026-31586 CVE-2026-31587                      CVE-2026-31588 CVE-2026-31590 CVE-2026-31593 CVE-2026-31594                      CVE-2026-31595 CVE-2026-31596 CVE-2026-31597 CVE-2026-31598                      CVE-2026-31599 CVE-2026-31602 CVE-2026-31603 CVE-2026-31604                      CVE-2026-31605 CVE-2026-31606 CVE-2026-31607 CVE-2026-31610                      CVE-2026-31611 CVE-2026-31612 CVE-2026-31614 CVE-2026-31615                      CVE-2026-31616 CVE-2026-31617 CVE-2026-31618 CVE-2026-31619                      CVE-2026-31622 CVE-2026-31623 CVE-2026-31624 CVE-2026-31625                      CVE-2026-31626 CVE-2026-31627 CVE-2026-31628 CVE-2026-31629                      CVE-2026-31634 CVE-2026-31637 CVE-2026-31638 CVE-2026-31639                      CVE-2026-31642 CVE-2026-31644 CVE-2026-31645 CVE-2026-31646                      CVE-2026-31647 CVE-2026-31648 CVE-2026-31649 CVE-2026-31651                      CVE-2026-31655 CVE-2026-31656 CVE-2026-31657 CVE-2026-31658                      CVE-2026-31659 CVE-2026-31660 CVE-2026-31661 CVE-2026-31662                      CVE-2026-31664 CVE-2026-31665 CVE-2026-31666 CVE-2026-31667                      CVE-2026-31668 CVE-2026-31669 CVE-2026-31670 CVE-2026-31671                      CVE-2026-31672 CVE-2026-31673 CVE-2026-31674 CVE-2026-31675                      CVE-2026-31676 CVE-2026-31677 CVE-2026-31678 CVE-2026-31679                      CVE-2026-31680 CVE-2026-31681 CVE-2026-31682 CVE-2026-31683                      CVE-2026-31684 CVE-2026-31685 CVE-2026-31686 CVE-2026-31689                      CVE-2026-31693 CVE-2026-31786 CVE-2026-31787 CVE-2026-31788

    Several vulnerabilities have been discovered in the Linux kernel that     may lead to a privilege escalation, denial of service or information     leaks.

    For the stable distribution (trixie), these problems have been fixed in     version 6.12.85-1.

    We recommend that you upgrade your linux packages.

    For the detailed security status of linux please refer to its security     tracker page at:
    https://security-tracker.debian.org/tracker/linux

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

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

  - net: dsa: properly keep track of conduit reference Problem description ------------------- DSA has a     mumbo-jumbo of reference handling of the conduit net device and its kobject which, sadly, is just wrong     and doesn't make sense. There are two distinct problems. 1. The OF path, which uses     of_find_net_device_by_node(), never releases the elevated refcount on the conduit's kobject. Nominally,     the OF and non-OF paths should result in objects having identical reference counts taken, and it is     already suspicious that dsa_dev_to_net_device() has a put_device() call which is missing in     dsa_port_parse_of(), but we can actually even verify that an issue exists. With     CONFIG_DEBUG_KOBJECT_RELEASE=y, if we run this command before and after applying this patch: (unbind     the conduit driver for net device eno2) echo 0000:00:00.2 > /sys/bus/pci/drivers/fsl_enetc/unbind we see     these lines in the output diff which appear only with the patch applied: kobject: 'eno2'     (ffff002009a3a6b8): kobject_release, parent 0000000000000000 (delayed 1000) kobject: '109'     (ffff0020099d59a0): kobject_release, parent 0000000000000000 (delayed 1000) 2. After we find the conduit     interface one way (OF) or another (non-OF), it can get unregistered at any time, and DSA remains with a     long-lived, but in this case stale, cpu_dp->conduit pointer. Holding the net device's underlying kobject     isn't actually of much help, it just prevents it from being freed (but we never need that kobject     directly). What helps us to prevent the net device from being unregistered is the parallel netdev     reference mechanism (dev_hold() and dev_put()). Actually we actually use that netdev tracker mechanism     implicitly on user ports since commit 2f1e8ea726e9 (net: dsa: link interfaces with the DSA master to get     rid of lockdep warnings), via netdev_upper_dev_link(). But time still passes at DSA switch probe time     between the initial of_find_net_device_by_node() code and the user port creation time, time during which     the conduit could unregister itself and DSA wouldn't know about it. So we have to run     of_find_net_device_by_node() under rtnl_lock() to prevent that from happening, and release the lock only     with the netdev tracker having acquired the reference. Do we need to keep the reference until     dsa_unregister_switch() / dsa_switch_shutdown()? 1: Maybe yes. A switch device will still be registered     even if all user ports failed to probe, see commit 86f8b1c01a0a (net: dsa: Do not make user port errors     fatal), and the cpu_dp->conduit pointers remain valid. I haven't audited all call paths to see whether     they will actually use the conduit in lack of any user port, but if they do, it seems safer to not rely on     user ports for that reference. 2. Definitely yes. We support changing the conduit which a user port is     associated to, and we can get into a situation where we've moved all user ports away from a conduit, thus     no longer hold any reference to it via the net device tracker. But we shouldn't let it go nonetheless -     see the next change in relation to dsa_tree_find_first_conduit() and LAG conduits which disappear. We have     to be prepared to return to the physical conduit, so the CPU port must explicitly keep another reference     to it. This is also to say: the user ports and their CPU ports may not always keep a reference to the same     conduit net device, and both are needed. As for the conduit's kobject for the /sys/class/net/ entry, we     don't care about it, we can release it as soon as we hold the net device object itself. History and blame     attribution ----------------------------- The code has been refactored so many times, it is very difficult     to follow and properly attribute a blame, but I'll try to make a short history which I hope to be correct.
    We have two distinct probing paths: - one for OF, introduced in 2016 i ---truncated--- (CVE-2025-71152)

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

ID	Name	Product	Family	Severity
315742	Ubuntu 25.10 / Pro Realtime 24.04 LTS : Linux kernel vulnerabilities (USN-8277-1)	Nessus	Ubuntu Local Security Checks	high
311299	Debian dsa-6238 : ata-modules-6.12.74+deb13+1-armmp-di - security update	Nessus	Debian Local Security Checks	high
296382	Linux Distros Unpatched Vulnerability : CVE-2025-71152	Nessus	Misc.	high

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