CVE-2025-71152 SUSE CVE security@suse.de SUSE Security Team SUSE CVE-2025-71152 Interim 1 1 2026-03-05T00:20:18Z current 2026-03-05T00:20:18Z 2026-03-05T00:20:18Z cve-database/bin/generate-cvrf-cve.pl 2020-12-27T01:00:00Z CVE-2025-71152 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 CVRF data is provided by SUSE under the Creative Commons License 4.0 with Attribution (CC-BY-4.0). https://www.suse.com/support/security/rating/ SUSE Security Ratings SUSE Linux Enterprise Module for Basesystem 15 SP7 SUSE Linux Enterprise Module for Development Tools 15 SP7 SUSE Linux Enterprise Workstation Extension 15 SP7 SUSE Linux Enterprise High Availability Extension 15 SP7 SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS SUSE Linux Enterprise Module for Basesystem 15 SP7 SUSE Linux Enterprise Module for Development Tools 15 SP7 SUSE Linux Enterprise Module for Legacy 15 SP7 SUSE Linux Enterprise Module for Public Cloud 15 SP7 SUSE Linux Enterprise Live Patching 12 SP5 SUSE Linux Enterprise Live Patching 15 SP4 SUSE Linux Enterprise Live Patching 15 SP5 SUSE Linux Enterprise Live Patching 15 SP7 SUSE Linux Enterprise Micro 5.0 SUSE Linux Enterprise Micro 5.1 SUSE Linux Enterprise Micro 5.2 SUSE Linux Enterprise Micro 5.3 SUSE Linux Enterprise Micro 5.4 SUSE Linux Enterprise Micro 5.5 SUSE Real Time Module 15 SP7 SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE SUSE Linux Enterprise Server 12 SP2-LTSS SUSE Linux Enterprise Server 12 SP4-LTSS SUSE Linux Enterprise Server 12 SP5-LTSS SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security SUSE Linux Enterprise Server 15 SP1-LTSS SUSE Linux Enterprise Server 15 SP2-LTSS SUSE Linux Enterprise Server 15 SP3-LTSS SUSE Linux Enterprise Server 15 SP4-LTSS SUSE Linux Enterprise Server 15 SP5-LTSS SUSE Linux Enterprise Server 15 SP6-LTSS SUSE Linux Enterprise Module for Basesystem 15 SP7 SUSE Linux Enterprise Module for Development Tools 15 SP7 SUSE Linux Enterprise Module for Legacy 15 SP7 SUSE Linux Enterprise Module for Public Cloud 15 SP7 SUSE Linux Enterprise Workstation Extension 15 SP7 SUSE Linux Enterprise Server 16.0 SUSE Linux Enterprise Server Teradata 12 SP3 SUSE Linux Enterprise Server Teradata 15 SP4 SUSE Linux Enterprise Server for SAP Applications 15 SP4 SUSE Linux Enterprise Server for SAP Applications 15 SP5 SUSE Linux Enterprise Server for SAP Applications 15 SP6 SUSE Linux Enterprise Module for Basesystem 15 SP7 SUSE Linux Enterprise Module for Development Tools 15 SP7 SUSE Linux Enterprise Module for Legacy 15 SP7 SUSE Linux Enterprise Module for Public Cloud 15 SP7 SUSE Linux Enterprise Workstation Extension 15 SP7 SUSE Linux Enterprise Server for SAP applications 16.0 SUSE Linux Micro 6.0 SUSE Linux Micro 6.1 openSUSE Leap 15.6 cluster-md-kmp-default dlm-kmp-default gfs2-kmp-default kernel-default kernel-default-base kernel-default-devel kernel-default-extra kernel-default-kgraft kernel-default-kgraft-devel kernel-default-livepatch kernel-default-livepatch-devel kernel-default-man kernel-default-optional kernel-default-vdso kernel-devel kernel-devel-azure kernel-devel-rt kernel-macros kernel-rt kernel-source kernel-source-azure kernel-source-rt kernel-source-vanilla kselftests-kmp-default ocfs2-kmp-default reiserfs-kmp-default cluster-md-kmp-default as a component of SUSE Linux Enterprise High Availability Extension 15 SP7 dlm-kmp-default as a component of SUSE Linux Enterprise High Availability Extension 15 SP7 gfs2-kmp-default as a component of SUSE Linux Enterprise High Availability Extension 15 SP7 ocfs2-kmp-default as a component of SUSE Linux Enterprise High Availability Extension 15 SP7 kernel-default as a component of SUSE Linux Enterprise High Availability Extension 15 SP7 kernel-source as a component of SUSE Linux Enterprise High Availability Extension 15 SP7 kernel-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-default-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-macros as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-source as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS cluster-md-kmp-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS dlm-kmp-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS gfs2-kmp-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-default-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS ocfs2-kmp-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-macros as a component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-source as a component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-default-kgraft as a component of SUSE Linux Enterprise Live Patching 12 SP5 kernel-default-kgraft-devel as a component of SUSE Linux Enterprise Live Patching 12 SP5 kernel-default as a component of SUSE Linux Enterprise Live Patching 12 SP5 kernel-source as a component of SUSE Linux Enterprise Live Patching 12 SP5 kernel-default-livepatch as a component of SUSE Linux Enterprise Live Patching 15 SP4 kernel-default-livepatch-devel as a component of SUSE Linux Enterprise Live Patching 15 SP4 kernel-default as a component of SUSE Linux Enterprise Live Patching 15 SP4 kernel-source as a component of SUSE Linux Enterprise Live Patching 15 SP4 kernel-default-livepatch as a component of SUSE Linux Enterprise Live Patching 15 SP5 kernel-default-livepatch-devel as a component of SUSE Linux Enterprise Live Patching 15 SP5 kernel-default as a component of SUSE Linux Enterprise Live Patching 15 SP5 kernel-source as a component of SUSE Linux Enterprise Live Patching 15 SP5 kernel-default-livepatch as a component of SUSE Linux Enterprise Live Patching 15 SP7 kernel-default-livepatch-devel as a component of SUSE Linux Enterprise Live Patching 15 SP7 kernel-default as a component of SUSE Linux Enterprise Live Patching 15 SP7 kernel-source as a component of SUSE Linux Enterprise Live Patching 15 SP7 kernel-default as a component of SUSE Linux Enterprise Micro 5.0 kernel-default as a component of SUSE Linux Enterprise Micro 5.1 kernel-rt as a component of SUSE Linux Enterprise Micro 5.1 kernel-default as a component of SUSE Linux Enterprise Micro 5.2 kernel-rt as a component of SUSE Linux Enterprise Micro 5.2 kernel-source as a component of SUSE Linux Enterprise Micro 5.2 kernel-source-rt as a component of SUSE Linux Enterprise Micro 5.2 kernel-default as a component of SUSE Linux Enterprise Micro 5.3 kernel-rt as a component of SUSE Linux Enterprise Micro 5.3 kernel-source as a component of SUSE Linux Enterprise Micro 5.3 kernel-source-rt as a component of SUSE Linux Enterprise Micro 5.3 kernel-default as a component of SUSE Linux Enterprise Micro 5.4 kernel-rt as a component of SUSE Linux Enterprise Micro 5.4 kernel-source as a component of SUSE Linux Enterprise Micro 5.4 kernel-source-rt as a component of SUSE Linux Enterprise Micro 5.4 kernel-default as a component of SUSE Linux Enterprise Micro 5.5 kernel-macros as a component of SUSE Linux Enterprise Micro 5.5 kernel-source as a component of SUSE Linux Enterprise Micro 5.5 kernel-devel-rt as a component of SUSE Linux Enterprise Micro 5.5 kernel-source-rt as a component of SUSE Linux Enterprise Micro 5.5 kernel-default as a component of SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-default-devel as a component of SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-devel as a component of SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-macros as a component of SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-source as a component of SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-default as a component of SUSE Linux Enterprise Module for Development Tools 15 SP7 kernel-source as a component of SUSE Linux Enterprise Module for Development Tools 15 SP7 reiserfs-kmp-default as a component of SUSE Linux Enterprise Module for Legacy 15 SP7 kernel-default as a component of SUSE Linux Enterprise Module for Legacy 15 SP7 kernel-source as a component of SUSE Linux Enterprise Module for Legacy 15 SP7 kernel-devel-azure as a component of SUSE Linux Enterprise Module for Public Cloud 15 SP7 kernel-source-azure as a component of SUSE Linux Enterprise Module for Public Cloud 15 SP7 kernel-default as a component of SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-default-base as a component of SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-default-devel as a component of SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-source as a component of SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-default as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-default-base as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-default-man as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-source as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-default as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default-base as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default-man as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-source as a component of SUSE Linux Enterprise Server 12 SP4-LTSS cluster-md-kmp-default as a component of SUSE Linux Enterprise Server 12 SP5-LTSS dlm-kmp-default as a component of SUSE Linux Enterprise Server 12 SP5-LTSS gfs2-kmp-default as a component of SUSE Linux Enterprise Server 12 SP5-LTSS kernel-default as a component of SUSE Linux Enterprise Server 12 SP5-LTSS kernel-default-base as a component of SUSE Linux Enterprise Server 12 SP5-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 12 SP5-LTSS kernel-default-man as a component of SUSE Linux Enterprise Server 12 SP5-LTSS ocfs2-kmp-default as a component of SUSE Linux Enterprise Server 12 SP5-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 12 SP5-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 12 SP5-LTSS kernel-source as a component of SUSE Linux Enterprise Server 12 SP5-LTSS kernel-default as a component of SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security kernel-source as a component of SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security kernel-default as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default-base as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default-man as a component of SUSE Linux Enterprise Server 15 SP1-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-source as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default as a component of SUSE Linux Enterprise Server 15 SP2-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 15 SP2-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise Server 15 SP2-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 15 SP2-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 15 SP2-LTSS kernel-source as a component of SUSE Linux Enterprise Server 15 SP2-LTSS kernel-default as a component of SUSE Linux Enterprise Server 15 SP3-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 15 SP3-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise Server 15 SP3-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 15 SP3-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 15 SP3-LTSS kernel-source as a component of SUSE Linux Enterprise Server 15 SP3-LTSS kernel-default as a component of SUSE Linux Enterprise Server 15 SP4-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 15 SP4-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise Server 15 SP4-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 15 SP4-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 15 SP4-LTSS kernel-source as a component of SUSE Linux Enterprise Server 15 SP4-LTSS cluster-md-kmp-default as a component of SUSE Linux Enterprise Server 15 SP5-LTSS dlm-kmp-default as a component of SUSE Linux Enterprise Server 15 SP5-LTSS gfs2-kmp-default as a component of SUSE Linux Enterprise Server 15 SP5-LTSS kernel-default as a component of SUSE Linux Enterprise Server 15 SP5-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 15 SP5-LTSS ocfs2-kmp-default as a component of SUSE Linux Enterprise Server 15 SP5-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise Server 15 SP5-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 15 SP5-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 15 SP5-LTSS kernel-source as a component of SUSE Linux Enterprise Server 15 SP5-LTSS cluster-md-kmp-default as a component of SUSE Linux Enterprise Server 15 SP6-LTSS dlm-kmp-default as a component of SUSE Linux Enterprise Server 15 SP6-LTSS gfs2-kmp-default as a component of SUSE Linux Enterprise Server 15 SP6-LTSS kernel-default as a component of SUSE Linux Enterprise Server 15 SP6-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 15 SP6-LTSS ocfs2-kmp-default as a component of SUSE Linux Enterprise Server 15 SP6-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise Server 15 SP6-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 15 SP6-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 15 SP6-LTSS kernel-source as a component of SUSE Linux Enterprise Server 15 SP6-LTSS kernel-default as a component of SUSE Linux Enterprise Server 16.0 kernel-devel as a component of SUSE Linux Enterprise Server 16.0 kernel-macros as a component of SUSE Linux Enterprise Server 16.0 kernel-source as a component of SUSE Linux Enterprise Server 16.0 kernel-source-vanilla as a component of SUSE Linux Enterprise Server 16.0 kernel-devel-azure as a component of SUSE Linux Enterprise Server 16.0 kernel-source-azure as a component of SUSE Linux Enterprise Server 16.0 kernel-default as a component of SUSE Linux Enterprise Server Teradata 12 SP3 kernel-source as a component of SUSE Linux Enterprise Server Teradata 12 SP3 kernel-default as a component of SUSE Linux Enterprise Server Teradata 15 SP4 kernel-source as a component of SUSE Linux Enterprise Server Teradata 15 SP4 kernel-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-default-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP4 reiserfs-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-macros as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-source as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP4 cluster-md-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP5 dlm-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP5 gfs2-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-default-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP5 ocfs2-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP5 reiserfs-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-macros as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-source as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP5 cluster-md-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP6 dlm-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP6 gfs2-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-default-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP6 ocfs2-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP6 reiserfs-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-macros as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-source as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-default as a component of SUSE Linux Enterprise Server for SAP applications 16.0 kernel-devel as a component of SUSE Linux Enterprise Server for SAP applications 16.0 kernel-macros as a component of SUSE Linux Enterprise Server for SAP applications 16.0 kernel-source as a component of SUSE Linux Enterprise Server for SAP applications 16.0 kernel-source-vanilla as a component of SUSE Linux Enterprise Server for SAP applications 16.0 kernel-devel-azure as a component of SUSE Linux Enterprise Server for SAP applications 16.0 kernel-source-azure as a component of SUSE Linux Enterprise Server for SAP applications 16.0 kernel-default-extra as a component of SUSE Linux Enterprise Workstation Extension 15 SP7 kernel-default as a component of SUSE Linux Enterprise Workstation Extension 15 SP7 kernel-source as a component of SUSE Linux Enterprise Workstation Extension 15 SP7 kernel-default as a component of SUSE Linux Micro 6.0 kernel-devel as a component of SUSE Linux Micro 6.0 kernel-macros as a component of SUSE Linux Micro 6.0 kernel-source as a component of SUSE Linux Micro 6.0 kernel-devel-rt as a component of SUSE Linux Micro 6.0 kernel-source-rt as a component of SUSE Linux Micro 6.0 kernel-default as a component of SUSE Linux Micro 6.1 kernel-devel as a component of SUSE Linux Micro 6.1 kernel-macros as a component of SUSE Linux Micro 6.1 kernel-source as a component of SUSE Linux Micro 6.1 kernel-devel-rt as a component of SUSE Linux Micro 6.1 kernel-source-rt as a component of SUSE Linux Micro 6.1 kernel-devel-rt as a component of SUSE Real Time Module 15 SP7 kernel-source-rt as a component of SUSE Real Time Module 15 SP7 cluster-md-kmp-default as a component of openSUSE Leap 15.6 dlm-kmp-default as a component of openSUSE Leap 15.6 gfs2-kmp-default as a component of openSUSE Leap 15.6 kernel-default as a component of openSUSE Leap 15.6 kernel-default-devel as a component of openSUSE Leap 15.6 kernel-default-extra as a component of openSUSE Leap 15.6 kernel-default-livepatch as a component of openSUSE Leap 15.6 kernel-default-livepatch-devel as a component of openSUSE Leap 15.6 kernel-default-optional as a component of openSUSE Leap 15.6 kernel-default-vdso as a component of openSUSE Leap 15.6 kselftests-kmp-default as a component of openSUSE Leap 15.6 ocfs2-kmp-default as a component of openSUSE Leap 15.6 reiserfs-kmp-default as a component of openSUSE Leap 15.6 kernel-devel as a component of openSUSE Leap 15.6 kernel-macros as a component of openSUSE Leap 15.6 kernel-source as a component of openSUSE Leap 15.6 kernel-source-vanilla as a component of openSUSE Leap 15.6 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--- CVE-2025-71152 SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE:kernel-default SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE:kernel-default-base SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE:kernel-default-devel SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE:kernel-source SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-default SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-default-base SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-default-devel SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-default-man SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-devel SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-macros SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-source SUSE Linux Enterprise Server Teradata 12 SP3:kernel-default SUSE Linux Enterprise Server Teradata 12 SP3:kernel-source moderate 6.3 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H