CVE-2025-38109: linux kernel Use-After-Free — Fix

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 ]---

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
linux	linux_kernel	6.5 — 6.6.94
linux	linux_kernel	6.7 — 6.12.34
linux	linux_kernel	6.13 — 6.15.3
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/24db585d369f949f698e03d7d8017e5ae19d0497 https://git.kernel.org/stable/c/5953ae44dfe5dbad374318875be834c3b7b71ee6 https://git.kernel.org/stable/c/687560d8a9a2d654829ad0da1ec24242f1de711d https://git.kernel.org/stable/c/da15ca0553325acf68039015f2f4db750c8e2b96

Frequently Asked Questions

What is CVE-2025-38109? +

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 ]--- It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2025-38109? +

CVE-2025-38109 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-38109? +

CVE-2025-38109 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-38109? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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