In the Linux kernel, the following vulnerability has been resolved: net: switchdev: Convert blocking notification chain to a raw one A blocking notification chain uses a read-write semaphore to protect the integrity of the chain. The semaphore is acquired for writing when adding / removing notifiers to / from the chain and acquired for reading when traversing the chain and informing notifiers about an event. In case of the blocking switchdev notification chain, recursive notifications are possible which leads to the semaphore being acquired twice for reading and to lockdep warnings being generated [1]. Specifically, this can happen when the bridge driver processes a SWITCHDEV_BRPORT_UNOFFLOADED event which causes it to emit notifications about deferred events when calling switchdev_deferred_process(). Fix this by converting the notification chain to a raw notification chain in a similar fashion to the netdev notification chain. Protect the chain using the RTNL mutex by acquiring it when modifying the chain. Events are always informed under the RTNL mutex, but add an assertion in call_switchdev_blocking_notifiers() to make sure this is not violated in the future. Maintain the "blocking" prefix as events are always emitted from process context and listeners are allowed to block. [1]: WARNING: possible recursive locking detected 6.14.0-rc4-custom-g079270089484 #1 Not tainted -------------------------------------------- ip/52731 is trying to acquire lock: ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0 but task is already holding lock: ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((switchdev_blocking_notif_chain).rwsem); lock((switchdev_blocking_notif_chain).rwsem); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by ip/52731: #0: ffffffff84f795b0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x727/0x1dc0 #1: ffffffff8731f628 (&net->rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x790/0x1dc0 #2: ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0 stack backtrace: ... ? __pfx_down_read+0x10/0x10 ? __pfx_mark_lock+0x10/0x10 ? __pfx_switchdev_port_attr_set_deferred+0x10/0x10 blocking_notifier_call_chain+0x58/0xa0 switchdev_port_attr_notify.constprop.0+0xb3/0x1b0 ? __pfx_switchdev_port_attr_notify.constprop.0+0x10/0x10 ? mark_held_locks+0x94/0xe0 ? switchdev_deferred_process+0x11a/0x340 switchdev_port_attr_set_deferred+0x27/0xd0 switchdev_deferred_process+0x164/0x340 br_switchdev_port_unoffload+0xc8/0x100 [bridge] br_switchdev_blocking_event+0x29f/0x580 [bridge] notifier_call_chain+0xa2/0x440 blocking_notifier_call_chain+0x6e/0xa0 switchdev_bridge_port_unoffload+0xde/0x1a0 ...

The remote Debian 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4193 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-4193-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                        Ben Hutchings     May 30, 2025                                  https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : linux-6.1     Version        : 6.1.137-1~deb11u1     CVE ID         : CVE-2023-52857 CVE-2023-52927 CVE-2023-53034 CVE-2024-24855                      CVE-2024-26656 CVE-2024-26739 CVE-2024-26767 CVE-2024-26982                      CVE-2024-27056 CVE-2024-35866 CVE-2024-36908 CVE-2024-38541                      CVE-2024-38611 CVE-2024-40973 CVE-2024-42129 CVE-2024-43831                      CVE-2024-46733 CVE-2024-46742 CVE-2024-46753 CVE-2024-46772                      CVE-2024-46774 CVE-2024-46816 CVE-2024-46823 CVE-2024-47753                      CVE-2024-47754 CVE-2024-50056 CVE-2024-50063 CVE-2024-50246                      CVE-2024-53166 CVE-2024-56609 CVE-2024-57977 CVE-2024-58002                      CVE-2024-58005 CVE-2024-58079 CVE-2024-58090 CVE-2025-21702                      CVE-2025-21712 CVE-2025-21721 CVE-2025-21756 CVE-2025-21838                      CVE-2025-21844 CVE-2025-21846 CVE-2025-21848 CVE-2025-21853                      CVE-2025-21855 CVE-2025-21858 CVE-2025-21859 CVE-2025-21862                      CVE-2025-21864 CVE-2025-21865 CVE-2025-21866 CVE-2025-21867                      CVE-2025-21871 CVE-2025-21875 CVE-2025-21877 CVE-2025-21878                      CVE-2025-21881 CVE-2025-21887 CVE-2025-21891 CVE-2025-21898                      CVE-2025-21899 CVE-2025-21904 CVE-2025-21905 CVE-2025-21909                      CVE-2025-21910 CVE-2025-21912 CVE-2025-21913 CVE-2025-21914                      CVE-2025-21916 CVE-2025-21917 CVE-2025-21918 CVE-2025-21919                      CVE-2025-21920 CVE-2025-21922 CVE-2025-21924 CVE-2025-21925                      CVE-2025-21926 CVE-2025-21928 CVE-2025-21934 CVE-2025-21935                      CVE-2025-21936 CVE-2025-21937 CVE-2025-21938 CVE-2025-21941                      CVE-2025-21943 CVE-2025-21944 CVE-2025-21945 CVE-2025-21947                      CVE-2025-21948 CVE-2025-21950 CVE-2025-21951 CVE-2025-21956                      CVE-2025-21957 CVE-2025-21959 CVE-2025-21960 CVE-2025-21962                      CVE-2025-21963 CVE-2025-21964 CVE-2025-21968 CVE-2025-21970                      CVE-2025-21971 CVE-2025-21975 CVE-2025-21978 CVE-2025-21979                      CVE-2025-21980 CVE-2025-21981 CVE-2025-21986 CVE-2025-21991                      CVE-2025-21992 CVE-2025-21993 CVE-2025-21994 CVE-2025-21996                      CVE-2025-21997 CVE-2025-21999 CVE-2025-22004 CVE-2025-22005                      CVE-2025-22007 CVE-2025-22008 CVE-2025-22010 CVE-2025-22014                      CVE-2025-22015 CVE-2025-22018 CVE-2025-22020 CVE-2025-22021                      CVE-2025-22025 CVE-2025-22027 CVE-2025-22033 CVE-2025-22035                      CVE-2025-22038 CVE-2025-22040 CVE-2025-22041 CVE-2025-22042                      CVE-2025-22044 CVE-2025-22045 CVE-2025-22049 CVE-2025-22050                      CVE-2025-22054 CVE-2025-22055 CVE-2025-22056 CVE-2025-22058                      CVE-2025-22060 CVE-2025-22063 CVE-2025-22066 CVE-2025-22071                      CVE-2025-22072 CVE-2025-22073 CVE-2025-22075 CVE-2025-22079                      CVE-2025-22081 CVE-2025-22086 CVE-2025-22088 CVE-2025-22089                      CVE-2025-22093 CVE-2025-22095 CVE-2025-22097 CVE-2025-22126                      CVE-2025-23136 CVE-2025-23138 CVE-2025-23140 CVE-2025-23141                      CVE-2025-23142 CVE-2025-23144 CVE-2025-23145 CVE-2025-23146                      CVE-2025-23147 CVE-2025-23148 CVE-2025-23150 CVE-2025-23151                      CVE-2025-23156 CVE-2025-23157 CVE-2025-23158 CVE-2025-23159                      CVE-2025-23161 CVE-2025-23163 CVE-2025-37738 CVE-2025-37739                      CVE-2025-37740 CVE-2025-37741 CVE-2025-37742 CVE-2025-37748                      CVE-2025-37749 CVE-2025-37752 CVE-2025-37756 CVE-2025-37757                      CVE-2025-37758 CVE-2025-37765 CVE-2025-37766 CVE-2025-37767                      CVE-2025-37768 CVE-2025-37769 CVE-2025-37770 CVE-2025-37771                      CVE-2025-37772 CVE-2025-37773 CVE-2025-37775 CVE-2025-37778                      CVE-2025-37780 CVE-2025-37781 CVE-2025-37782 CVE-2025-37785                      CVE-2025-37787 CVE-2025-37788 CVE-2025-37789 CVE-2025-37790                      CVE-2025-37792 CVE-2025-37794 CVE-2025-37796 CVE-2025-37797                      CVE-2025-37798 CVE-2025-37801 CVE-2025-37803 CVE-2025-37805                      CVE-2025-37808 CVE-2025-37810 CVE-2025-37811 CVE-2025-37812                      CVE-2025-37815 CVE-2025-37817 CVE-2025-37818 CVE-2025-37820                      CVE-2025-37823 CVE-2025-37824 CVE-2025-37829 CVE-2025-37830                      CVE-2025-37836 CVE-2025-37838 CVE-2025-37839 CVE-2025-37840                      CVE-2025-37841 CVE-2025-37844 CVE-2025-37849 CVE-2025-37850                      CVE-2025-37851 CVE-2025-37852 CVE-2025-37854 CVE-2025-37857                      CVE-2025-37858 CVE-2025-37859 CVE-2025-37862 CVE-2025-37865                      CVE-2025-37867 CVE-2025-37871 CVE-2025-37875 CVE-2025-37879                      CVE-2025-37881 CVE-2025-37883 CVE-2025-37884 CVE-2025-37885                      CVE-2025-37889 CVE-2025-37892 CVE-2025-37937 CVE-2025-37938                      CVE-2025-37940 CVE-2025-37979 CVE-2025-37982 CVE-2025-37983                      CVE-2025-37985 CVE-2025-37989 CVE-2025-38152 CVE-2025-38575                      CVE-2025-38637 CVE-2025-39728 CVE-2025-39735     Debian Bug     : 1050352 1086175 1088682 1100746 1100928 1103277

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

    For Debian 11 bullseye, these problems have been fixed in version     6.1.137-1~deb11u1.  This additionally includes many more bug fixes     from stable updates 6.1.130-6.1.137 and an update of the Microsoft     Azure Network Adapter (mana) driver.

    We recommend that you upgrade your linux-6.1 packages.

    For the detailed security status of linux-6.1 please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/linux-6.1

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS     Attachment:
    signature.asc     Description: PGP signature

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 remote Debian 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-5900 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-5900-1                   security@debian.org     https://www.debian.org/security/                     Salvatore Bonaccorso     April 12, 2025                        https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : linux     CVE ID         : CVE-2023-52857 CVE-2023-52927 CVE-2024-24855 CVE-2024-26656                      CVE-2024-26767 CVE-2024-26982 CVE-2024-27056 CVE-2024-35866                      CVE-2024-38611 CVE-2024-40973 CVE-2024-42129 CVE-2024-43831                      CVE-2024-46772 CVE-2024-47753 CVE-2024-47754 CVE-2024-50056                      CVE-2024-50246 CVE-2024-53166 CVE-2024-57977 CVE-2024-58002                      CVE-2024-58005 CVE-2024-58079 CVE-2024-58090 CVE-2025-21702                      CVE-2025-21712 CVE-2025-21721 CVE-2025-21756 CVE-2025-21838                      CVE-2025-21844 CVE-2025-21846 CVE-2025-21848 CVE-2025-21855                      CVE-2025-21858 CVE-2025-21859 CVE-2025-21862 CVE-2025-21864                      CVE-2025-21865 CVE-2025-21866 CVE-2025-21867 CVE-2025-21871                      CVE-2025-21875 CVE-2025-21877 CVE-2025-21878 CVE-2025-21881                      CVE-2025-21887 CVE-2025-21891 CVE-2025-21898 CVE-2025-21899                      CVE-2025-21904 CVE-2025-21905 CVE-2025-21909 CVE-2025-21910                      CVE-2025-21912 CVE-2025-21913 CVE-2025-21914 CVE-2025-21916                      CVE-2025-21917 CVE-2025-21918 CVE-2025-21919 CVE-2025-21920                      CVE-2025-21922 CVE-2025-21924 CVE-2025-21925 CVE-2025-21926                      CVE-2025-21928 CVE-2025-21934 CVE-2025-21935 CVE-2025-21936                      CVE-2025-21937 CVE-2025-21938 CVE-2025-21941 CVE-2025-21943                      CVE-2025-21944 CVE-2025-21945 CVE-2025-21947 CVE-2025-21948                      CVE-2025-21950 CVE-2025-21951 CVE-2025-21956 CVE-2025-21957                      CVE-2025-21959 CVE-2025-21960 CVE-2025-21962 CVE-2025-21963                      CVE-2025-21964 CVE-2025-21968 CVE-2025-21970 CVE-2025-21971                      CVE-2025-21975 CVE-2025-21978 CVE-2025-21979 CVE-2025-21980                      CVE-2025-21981 CVE-2025-21986 CVE-2025-21991 CVE-2025-21992                      CVE-2025-21993 CVE-2025-21994 CVE-2025-21996 CVE-2025-21997                      CVE-2025-21999 CVE-2025-22004 CVE-2025-22005 CVE-2025-22007                      CVE-2025-22008 CVE-2025-22010 CVE-2025-22014 CVE-2025-22015

    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 (bookworm), these problems have been fixed in     version 6.1.133-1.

    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.

ID	Name	Product	Family	Severity
237504	Debian dla-4193 : linux-config-6.1 - security update	Nessus	Debian Local Security Checks	high
234309	Debian dsa-5900 : affs-modules-6.1.0-28-4kc-malta-di - security update	Nessus	Debian Local Security Checks	high

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