CVE-2025-38019

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
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc6:*:*:*:*:*:*

History

14 Nov 2025, 19:01

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/92ec4855034b2c4d13f117558dc73d20581fa9ff - () https://git.kernel.org/stable/c/92ec4855034b2c4d13f117558dc73d20581fa9ff - Patch
References () https://git.kernel.org/stable/c/9ab7945f3a61ed23da412e30f1e56414c05c4f06 - () https://git.kernel.org/stable/c/9ab7945f3a61ed23da412e30f1e56414c05c4f06 - Patch
References () https://git.kernel.org/stable/c/abc43c1ffdbc801b0b04ac845bfaf1d42b8f68f7 - () https://git.kernel.org/stable/c/abc43c1ffdbc801b0b04ac845bfaf1d42b8f68f7 - Patch
References () https://git.kernel.org/stable/c/f1ecccb5cdda39bca8cd17bb0b6cf61361e33578 - () https://git.kernel.org/stable/c/f1ecccb5cdda39bca8cd17bb0b6cf61361e33578 - Patch
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mlxsw: spectrum_router: Se corrige el use-after-free al eliminar dispositivos de red GRE. El controlador solo descarga a los vecinos que se construyen sobre dispositivos de red registrados por él o sus superiores (que son todos Ethernet). El dispositivo admite la encapsulación y desencapsulación GRE del tráfico reenviado, pero el controlador no descargará vecinos ficticios construidos sobre dispositivos de red GRE ya que no son superiores a sus dispositivos de red: # ip link add name gre1 up type gre tos heritage 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 (Tenga en cuenta que el vecino no está marcado con 'offload') Cuando se vuelve a cargar el controlador y se reproduce la configuración existente, el controlador no realiza la misma comprobación con respecto a los vecinos existentes y descarga el agregado previamente: # 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 Si el vecino se elimina más tarde, el controlador ignorará la notificación (dado que el dispositivo de red GRE no es su superior) y, por lo tanto, seguirá haciendo referencia a la memoria liberada, lo que dará como resultado un use-after-free [1] cuando se elimine el dispositivo de red: # ip neigh del 0.0.0.0 lladdr 0.0.0.0 dev gre1 # ip link del dev gre1 Se soluciona omitiendo la reproducción del vecino si el dispositivo de red para el que se realiza la reproducción no es nuestro superior. [1] ERROR: KASAN: slab-use-after-free en mlxsw_sp_neigh_entry_update+0x1ea/0x200 Lectura de tamaño 8 en la dirección ffff888155b0e420 por la tarea ip/2282 [...] Rastreo de llamadas: 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
First Time Linux
Linux linux Kernel
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.8
CWE CWE-416
CPE cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc6:*:*:*:*:*:*

18 Jun 2025, 10:15

Type Values Removed Values Added
New CVE

Information

Published : 2025-06-18 10:15

Updated : 2025-11-14 19:01


NVD link : CVE-2025-38019

Mitre link : CVE-2025-38019

CVE.ORG link : CVE-2025-38019


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-416

Use After Free