CVE-2025-38109 net/mlx5: Fix ECVF vports unload on shutdown flow
A use-after-free vulnerability in the Linux kernel mlx5 driver causes a crash during shutdown when ECVF vports are used on BlueField devices.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-38109?
CVE-2025-38109 is a high-severity use after free vulnerability in Linux kernel, published on 3 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Fix ECVF vports unload on shutdown flow
Fix shutdown flow UAF when a virtual function is created on the embedded chip (ECVF) of a BlueField device. In such case the vport acl ingress table is not properly destroyed.
ECVF functionality is independent of ecpf_vport_exists capability and thus functions mlx5_eswitch_(enable|disable)_pf_vf_vports() should not test it when enabling/disabling ECVF vports.
kernel log: [] refcount_t: underflow; use-after-free. [] WARNING: CPU: 3 PID: 1 at lib/refcount.c:28 refcount_warn_saturate+0x124/0x220 ---------------- [] Call trace: [] refcount_warn_saturate+0x124/0x220 [] tree_put_node+0x164/0x1e0 [mlx5_core] [] mlx5_destroy_flow_table+0x98/0x2c0 [mlx5_core] [] esw_acl_ingress_table_destroy+0x28/0x40 [mlx5_core] [] esw_acl_ingress_lgcy_cleanup+0x80/0xf4 [mlx5_core] [] esw_legacy_vport_acl_cleanup+0x44/0x60 [mlx5_core] [] esw_vport_cleanup+0x64/0x90 [mlx5_core] [] mlx5_esw_vport_disable+0xc0/0x1d0 [mlx5_core] [] mlx5_eswitch_unload_ec_vf_vports+0xcc/0x150 [mlx5_core] [] mlx5_eswitch_disable_sriov+0x198/0x2a0 [mlx5_core] [] mlx5_device_disable_sriov+0xb8/0x1e0 [mlx5_core] [] mlx5_sriov_detach+0x40/0x50 [mlx5_core] [] mlx5_unload+0x40/0xc4 [mlx5_core] [] mlx5_unload_one_devl_locked+0x6c/0xe4 [mlx5_core] [] mlx5_unload_one+0x3c/0x60 [mlx5_core] [] shutdown+0x7c/0xa4 [mlx5_core] [] pci_device_shutdown+0x3c/0xa0 [] device_shutdown+0x170/0x340 [] __do_sys_reboot+0x1f4/0x2a0 [] __arm64_sys_reboot+0x2c/0x40 [] invoke_syscall+0x78/0x100 [] el0_svc_common.constprop.0+0x54/0x184 [] do_el0_svc+0x30/0xac [] el0_svc+0x48/0x160 [] el0t_64_sync_handler+0xa4/0x12c [] el0t_64_sync+0x1a4/0x1a8 [] --[ end trace 9c4601d68c70030e ]---
Weakness: CWE-416
Which versions are affected by CVE-2025-38109?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-38109?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-38109 being exploited?
There is no known exploitation of CVE-2025-38109 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-64517, BELL-CVE-2025-38109, DEBIAN-CVE-2025-38109, GHSA-hv7w-4qc7-rw79, ROOT-OS-UBUNTU-2204-CVE-2025-38109, ROOT-OS-UBUNTU-2404-CVE-2025-38109 and 1 more.