CVE-2025-38020

Published Jun 18, 2025

Last updated 10 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Disable MACsec offload for uplink representor profile MACsec offload is not supported in switchdev mode for uplink representors. When switching to the uplink representor profile, the MACsec offload feature must be cleared from the netdevice's features. If left enabled, attempts to add offloads result in a null pointer dereference, as the uplink representor does not support MACsec offload even though the feature bit remains set. Clear NETIF_F_HW_MACSEC in mlx5e_fix_uplink_rep_features(). Kernel log: Oops: general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f] CPU: 29 UID: 0 PID: 4714 Comm: ip Not tainted 6.14.0-rc4_for_upstream_debug_2025_03_02_17_35 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:__mutex_lock+0x128/0x1dd0 Code: d0 7c 08 84 d2 0f 85 ad 15 00 00 8b 35 91 5c fe 03 85 f6 75 29 49 8d 7e 60 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a6 15 00 00 4d 3b 76 60 0f 85 fd 0b 00 00 65 ff RSP: 0018:ffff888147a4f160 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 000000000000000f RSI: 0000000000000000 RDI: 0000000000000078 RBP: ffff888147a4f2e0 R08: ffffffffa05d2c19 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000018 R15: ffff888152de0000 FS: 00007f855e27d800(0000) GS:ffff88881ee80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004e5768 CR3: 000000013ae7c005 CR4: 0000000000372eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 Call Trace: <TASK> ? die_addr+0x3d/0xa0 ? exc_general_protection+0x144/0x220 ? asm_exc_general_protection+0x22/0x30 ? mlx5e_macsec_add_secy+0xf9/0x700 [mlx5_core] ? __mutex_lock+0x128/0x1dd0 ? lockdep_set_lock_cmp_fn+0x190/0x190 ? mlx5e_macsec_add_secy+0xf9/0x700 [mlx5_core] ? mutex_lock_io_nested+0x1ae0/0x1ae0 ? lock_acquire+0x1c2/0x530 ? macsec_upd_offload+0x145/0x380 ? lockdep_hardirqs_on_prepare+0x400/0x400 ? kasan_save_stack+0x30/0x40 ? kasan_save_stack+0x20/0x40 ? kasan_save_track+0x10/0x30 ? __kasan_kmalloc+0x77/0x90 ? __kmalloc_noprof+0x249/0x6b0 ? genl_family_rcv_msg_attrs_parse.constprop.0+0xb5/0x240 ? mlx5e_macsec_add_secy+0xf9/0x700 [mlx5_core] mlx5e_macsec_add_secy+0xf9/0x700 [mlx5_core] ? mlx5e_macsec_add_rxsa+0x11a0/0x11a0 [mlx5_core] macsec_update_offload+0x26c/0x820 ? macsec_set_mac_address+0x4b0/0x4b0 ? lockdep_hardirqs_on_prepare+0x284/0x400 ? _raw_spin_unlock_irqrestore+0x47/0x50 macsec_upd_offload+0x2c8/0x380 ? macsec_update_offload+0x820/0x820 ? __nla_parse+0x22/0x30 ? genl_family_rcv_msg_attrs_parse.constprop.0+0x15e/0x240 genl_family_rcv_msg_doit+0x1cc/0x2a0 ? genl_family_rcv_msg_attrs_parse.constprop.0+0x240/0x240 ? cap_capable+0xd4/0x330 genl_rcv_msg+0x3ea/0x670 ? genl_family_rcv_msg_dumpit+0x2a0/0x2a0 ? lockdep_set_lock_cmp_fn+0x190/0x190 ? macsec_update_offload+0x820/0x820 netlink_rcv_skb+0x12b/0x390 ? genl_family_rcv_msg_dumpit+0x2a0/0x2a0 ? netlink_ack+0xd80/0xd80 ? rwsem_down_read_slowpath+0xf90/0xf90 ? netlink_deliver_tap+0xcd/0xac0 ? netlink_deliver_tap+0x155/0xac0 ? _copy_from_iter+0x1bb/0x12c0 genl_rcv+0x24/0x40 netlink_unicast+0x440/0x700 ? netlink_attachskb+0x760/0x760 ? lock_acquire+0x1c2/0x530 ? __might_fault+0xbb/0x170 netlink_sendmsg+0x749/0xc10 ? netlink_unicast+0x700/0x700 ? __might_fault+0xbb/0x170 ? netlink_unicast+0x700/0x700 __sock_sendmsg+0xc5/0x190 ____sys_sendmsg+0x53f/0x760 ? import_iovec+0x7/0x10 ? kernel_sendmsg+0x30/0x30 ? __copy_msghdr+0x3c0/0x3c0 ? filter_irq_stacks+0x90/0x90 ? stack_depot_save_flags+0x28/0xa30 ___sys_sen ---truncated---
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel, debian_linux

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-476

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: cgroup: Avoid iteration of dying tasks with zero refcount The commit 260fbcb92bbea ("cgroup: Move dying_tasks cleanup from cgroup_task_release() to cgroup_task_free()") extended the lifetime of tasks on the dying_tasks list. The iterators have provision to go through dying_tasks because of dying threadgroup leaders or explicit CSS_TASK_ITER_WITH_DEAD, however, it was expected that such tasks can obtain a new reference (that is possible before cgroup_task_release()/put_task_struct_rcu_user()). The tasks after cgroup_task_release() and before cgroup_task_free() are subject to race when they may or may not have ->usage count > 0. The race window is between css_task_iter_next() invocations when css_set_lock is released and we may arrive at a new ->task_pos. The iterator should not attempt to resurrect tasks whose ->usage count dropped to zero. (When that happens, __put_task_struct_rcu_cb() is already imminent and the returned task_struct would could be used after free.) As for the fix, we cannot simply check the signal->live count of a task on the dying list because that won't distinguish regular zombies waiting to be reaped from RCU remnant tasks that are going to be free'd. Therefore add an extra check to rule out ->usage==0 tasks from any iteration. The repeat: loop in css_task_iter_advance() doesn't consider ->usage count, so add a new loop to css_task_iter_next() to skip de-used tasks on the dying_list. Rough illustration of the possible race R (reader of cgroup.procs) T (thread) L (group leader) --------------------------------- -------------------------------- -------------------------------- L exits, signal->live > 0 cgroup_task_dead(L) css_set_skip_task_iters() // skips only cset->tasks list_add_tail(&L->cg_list, &cset->dying_tasks) css_task_iter_next() take css_set_lock css_task_iter_advance() leader && signal->live != 0 => it->task_pos = &L->cg_list release css_set_lock T exits --signal->live == 0 cgroup_task_dead(T) // css_set_lock release_task(T) cgroup_task_release(T) release_task(L) // zap_leader cgroup_task_release(L) put_task_struct_rcu_user(L) ...RCU... put_task_struct(L) L->usage = 0 /* L still on dying_tasks */ ...RCU... __put_task_struct(L) css_task_iter_next() // another iteration take css_set_lock it->task_pos = &L->cg_list get_task_struct(L) => addition on 0 drop css_set_lock cgroup_task_free(L) css_set_skip_task_iters() // dying skip comes too late free_task(L) cgroup_procs_show() task_pid_vnr(L)•CVE-2026-98163