In the Linux kernel, the following vulnerability has been resolved:
mlxsw: spectrum_router: Fix use-after-free when deleting GRE net devices
The driver only offloads neighbors that are constructed on top of net devices registered by it or their uppers (which are all Ethernet). The device supports GRE encapsulation and decapsulation of forwarded traffic, but the driver will not offload dummy neighbors constructed on top of GRE net devices as they are not uppers of its net devices:
# ip link add name gre1 up type gre tos inherit local 192.0.2.1 remote 198.51.100.1 # ip neigh add 0.0.0.0 lladdr 0.0.0.0 nud noarp dev gre1 $ ip neigh show dev gre1 nud noarp 0.0.0.0 lladdr 0.0.0.0 NOARP
(Note that the neighbor is not marked with 'offload')
When the driver is reloaded and the existing configuration is replayed, the driver does not perform the same check regarding existing neighbors and offloads the previously added one:
# devlink dev reload pci/0000:01:00.0 $ ip neigh show dev gre1 nud noarp 0.0.0.0 lladdr 0.0.0.0 offload NOARP
If the neighbor is later deleted, the driver will ignore the notification (given the GRE net device is not its upper) and will therefore keep referencing freed memory, resulting in a use-after-free [1] when the net device is deleted:
# ip neigh del 0.0.0.0 lladdr 0.0.0.0 dev gre1 # ip link del dev gre1
Fix by skipping neighbor replay if the net device for which the replay is performed is not our upper.
[1] BUG: KASAN: slab-use-after-free in mlxsw_sp_neigh_entry_update+0x1ea/0x200 Read of size 8 at addr ffff888155b0e420 by task ip/2282 [...] Call Trace: <TASK> dump_stack_lvl+0x6f/0xa0 print_address_description.constprop.0+0x6f/0x350 print_report+0x108/0x205 kasan_report+0xdf/0x110 mlxsw_sp_neigh_entry_update+0x1ea/0x200 mlxsw_sp_router_rif_gone_sync+0x2a8/0x440 mlxsw_sp_rif_destroy+0x1e9/0x750 mlxsw_sp_netdevice_ipip_ol_event+0x3c9/0xdc0 mlxsw_sp_router_netdevice_event+0x3ac/0x15e0 notifier_call_chain+0xca/0x150 call_netdevice_notifiers_info+0x7f/0x100 unregister_netdevice_many_notify+0xc8c/0x1d90 rtnl_dellink+0x34e/0xa50 rtnetlink_rcv_msg+0x6fb/0xb70 netlink_rcv_skb+0x131/0x360 netlink_unicast+0x426/0x710 netlink_sendmsg+0x75a/0xc20 __sock_sendmsg+0xc1/0x150 ____sys_sendmsg+0x5aa/0x7b0 ___sys_sendmsg+0xfc/0x180 __sys_sendmsg+0x121/0x1b0 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x4b/0x53
CVSS Details
- CVSS 3.1 Base Score: 7.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade linux | Jul 23, 2026 | Jul 23, 2026 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | Jun 18, 2025 |
| Suse | — | Upgrade kernel-64kb-optionalUpgrade cluster-md-kmp-defaultUpgrade dlm-kmp-defaultUpgrade dtb-amdUpgrade dtb-hisiliconUpgrade dtb-sprdUpgrade kernel-64kbUpgrade kernel-kvmsmall-vdsoUpgrade dtb-nvidiaUpgrade kselftests-kmp-rtUpgrade dtb-marvellUpgrade dtb-freescaleUpgrade gfs2-kmp-defaultUpgrade dtb-apmUpgrade dtb-appleUpgrade kernel-default-develUpgrade cluster-md-kmp-64kbUpgrade dtb-amazonUpgrade kernel-default-livepatch-develUpgrade kernel-docs-htmlUpgrade dtb-broadcomUpgrade kernel-docsUpgrade kernel-64kb-extraUpgrade gfs2-kmp-64kbUpgrade dtb-amlogicUpgrade dtb-renesasUpgrade kernel-obs-qaUpgrade kernel-default-livepatchUpgrade kernel-rt-optionalUpgrade kernel-rt-vdsoUpgrade kernel-default-extraUpgrade kernel-macrosUpgrade kselftests-kmp-defaultUpgrade ocfs2-kmp-64kbUpgrade dtb-socionextUpgrade kernel-defaultUpgrade dlm-kmp-rtUpgrade kernel-rt-livepatch-develUpgrade kernel-symsUpgrade kernel-rt-extraUpgrade kernel-kvmsmallUpgrade kernel-obs-buildUpgrade kernel-default-vdsoUpgrade kernel-64kb-develUpgrade cluster-md-kmp-rtUpgrade kselftests-kmp-64kbUpgrade dtb-armUpgrade kernel-develUpgrade kernel-rtUpgrade kernel-kvmsmall-develUpgrade dlm-kmp-64kbUpgrade dtb-exynosUpgrade dtb-qcomUpgrade dtb-mediatekUpgrade ocfs2-kmp-rtUpgrade dtb-allwinnerUpgrade ocfs2-kmp-defaultUpgrade dtb-rockchipUpgrade kernel-source-vanillaUpgrade kernel-default-optionalUpgrade dtb-xilinxUpgrade kernel-rt-livepatchUpgrade kernel-rt-develUpgrade dtb-caviumUpgrade kernel-zfcpdumpUpgrade kernel-sourceUpgrade gfs2-kmp-rtUpgrade dtb-lgUpgrade dtb-altera | Dec 5, 2025 | Nov 6, 2025 |
| Ubuntu | — | Upgrade linux-image-virtual-6.8Upgrade linux-image-raspiUpgrade linux-image-realtime-6.8.1Upgrade linux-image-xilinx-zynqmpUpgrade linux-image-raspi-6.14Upgrade linux-image-gke-6.8Upgrade linux-image-gke-64k-6.8Upgrade linux-image-gcp-64k-6.8Upgrade linux-image-oracle-64k-lts-24.04Upgrade linux-image-azureUpgrade linux-image-realtime-6.14Upgrade linux-image-kvmUpgrade linux-image-realtime-hwe-22.04Upgrade linux-image-6.8.0-1046-azure-fipsUpgrade linux-image-6.8.0-1047-gcpUpgrade linux-image-6.8.0-1046-nvidia-lowlatency-64kUpgrade linux-image-generic-6.14Upgrade linux-image-nvidia-64kUpgrade linux-image-nvidia-lowlatency-64k-6.8Upgrade linux-image-6.8.0-1046-aws-fipsUpgrade linux-image-nvidia-lowlatencyUpgrade linux-image-oem-24.04aUpgrade linux-image-ibm-lts-24.04Upgrade linux-image-nvidia-6.8Upgrade linux-image-generic-hwe-24.04Upgrade linux-image-6.8.0-1046-awsUpgrade linux-image-virtual-hwe-22.04Upgrade linux-image-6.8.0-100-lowlatencyUpgrade linux-image-6.8.0-1043-gkeUpgrade linux-image-gcp-64k-6.14Upgrade linux-image-nvidia-hwe-22.04Upgrade linux-image-6.14.0-1011-oracleUpgrade linux-image-gcp-lts-24.04Upgrade linux-image-6.8.0-1047-raspiUpgrade linux-image-aws-64k-6.14Upgrade linux-image-gcp-6.14Upgrade linux-image-oem-24.04cUpgrade linux-image-oem-22.04cUpgrade linux-image-intel-iotgUpgrade linux-image-6.8.0-1044-ibmUpgrade linux-image-generic-hwe-22.04Upgrade linux-image-raspi-6.8Upgrade linux-image-gcp-fips-6.8Upgrade linux-image-oracle-64k-6.14Upgrade linux-image-oem-22.04bUpgrade linux-image-aws-6.8Upgrade linux-image-virtual-6.14Upgrade linux-image-6.8.0-1023-xilinxUpgrade linux-image-generic-64kUpgrade linux-image-6.8.0-1043-oracleUpgrade linux-image-6.8.0-1043-oracle-64kUpgrade linux-image-xilinx-6.8Upgrade linux-image-lowlatency-64k-hwe-22.04Upgrade linux-image-aws-lts-24.04Upgrade linux-image-gcp-fipsUpgrade linux-image-realtimeUpgrade linux-image-oracle-6.8Upgrade linux-image-gcp-64kUpgrade linux-image-6.8.1-1041-realtimeUpgrade linux-image-aws-fips-6.8Upgrade linux-image-oracle-64kUpgrade linux-image-intel-iot-realtimeUpgrade linux-image-aws-6.14Upgrade linux-image-gke-64kUpgrade linux-image-oem-22.04dUpgrade linux-image-xilinxUpgrade linux-image-azure-fipsUpgrade linux-image-raspi-realtimeUpgrade linux-image-azure-fips-6.8Upgrade linux-image-raspi-realtime-6.8Upgrade linux-image-oem-6.14Upgrade linux-image-gkeopUpgrade linux-image-virtual-hwe-24.04Upgrade linux-image-generic-64k-hwe-22.04Upgrade linux-image-genericUpgrade linux-image-gcp-64k-lts-24.04Upgrade linux-image-azure-6.14Upgrade linux-image-6.14.0-28-generic-64kUpgrade linux-image-6.8.0-1047-gcp-64kUpgrade linux-image-6.14.0-1010-oemUpgrade linux-image-oem-22.04aUpgrade linux-image-nvidia-64k-6.8Upgrade linux-image-6.8.0-2037-raspi-realtimeUpgrade linux-image-6.8.0-1046-nvidia-64kUpgrade linux-image-6.8.0-100-generic-64kUpgrade linux-image-6.14.0-1010-realtimeUpgrade linux-image-6.8.0-1046-aws-64kUpgrade linux-image-6.8.0-1043-gke-64kUpgrade linux-image-generic-64k-6.14Upgrade linux-image-6.14.0-1011-aws-64kUpgrade linux-image-aws-fipsUpgrade linux-image-6.8.0-1051-azureUpgrade linux-image-6.14.0-1014-gcpUpgrade linux-image-6.14.0-1011-oracle-64kUpgrade linux-image-nvidia-lowlatency-6.8Upgrade linux-image-nvidiaUpgrade linux-image-lowlatency-64k-6.8Upgrade linux-image-generic-64k-hwe-24.04Upgrade linux-image-virtualUpgrade linux-image-oem-22.04Upgrade linux-image-gcpUpgrade linux-image-nvidia-64k-hwe-22.04Upgrade linux-image-lowlatency-64kUpgrade linux-image-oracle-lts-24.04Upgrade linux-image-oem-24.04Upgrade linux-image-nvidia-lowlatency-64kUpgrade linux-image-6.8.0-100-lowlatency-64kUpgrade linux-image-ibmUpgrade linux-image-6.8.0-100-genericUpgrade linux-image-azure-6.8Upgrade linux-image-generic-64k-6.8Upgrade linux-image-6.8.0-1030-gkeopUpgrade linux-image-fipsUpgrade linux-image-6.14.0-1012-raspiUpgrade linux-image-oracle-6.14Upgrade linux-image-gcp-6.8Upgrade linux-image-generic-lpaeUpgrade linux-image-gkeop-6.8Upgrade linux-image-oracle-64k-6.8Upgrade linux-image-aws-64k-lts-24.04Upgrade linux-image-6.14.0-1014-gcp-64kUpgrade linux-image-lowlatencyUpgrade linux-image-ibm-classicUpgrade linux-image-gkeUpgrade linux-image-ibm-6.8Upgrade linux-image-6.8.0-1047-gcp-fipsUpgrade linux-image-6.8.0-1046-nvidiaUpgrade linux-image-6.14.0-1011-awsUpgrade linux-image-6.14.0-1010-azureUpgrade linux-image-oracleUpgrade linux-image-lowlatency-hwe-22.04Upgrade linux-image-fips-6.8Upgrade linux-image-6.14.0-28-genericUpgrade linux-image-lowlatency-6.8Upgrade linux-image-generic-6.8Upgrade linux-image-azure-lts-24.04Upgrade linux-image-aws-64k-6.8Upgrade linux-image-aws-64kUpgrade linux-image-awsUpgrade linux-image-6.8.0-1046-nvidia-lowlatencyUpgrade linux-image-6.8.0-1046-azureUpgrade linux-image-6.8.0-100-fips | Jun 26, 2025 | Jun 18, 2025 |
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