CVE-2023-53393

Published Sep 18, 2025

Last updated 9 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix mlx5_ib_get_hw_stats when used for device Currently, when mlx5_ib_get_hw_stats() is used for device (port_num = 0), there is a special handling in order to use the correct counters, but, port_num is being passed down the stack without any change. Also, some functions assume that port_num >=1. As a result, the following oops can occur. BUG: unable to handle page fault for address: ffff89510294f1a8 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP CPU: 8 PID: 1382 Comm: devlink Tainted: G W 6.1.0-rc4_for_upstream_base_2022_11_10_16_12 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:_raw_spin_lock+0xc/0x20 Call Trace: <TASK> mlx5_ib_get_native_port_mdev+0x73/0xe0 [mlx5_ib] do_get_hw_stats.constprop.0+0x109/0x160 [mlx5_ib] mlx5_ib_get_hw_stats+0xad/0x180 [mlx5_ib] ib_setup_device_attrs+0xf0/0x290 [ib_core] ib_register_device+0x3bb/0x510 [ib_core] ? atomic_notifier_chain_register+0x67/0x80 __mlx5_ib_add+0x2b/0x80 [mlx5_ib] mlx5r_probe+0xb8/0x150 [mlx5_ib] ? auxiliary_match_id+0x6a/0x90 auxiliary_bus_probe+0x3c/0x70 ? driver_sysfs_add+0x6b/0x90 really_probe+0xcd/0x380 __driver_probe_device+0x80/0x170 driver_probe_device+0x1e/0x90 __device_attach_driver+0x7d/0x100 ? driver_allows_async_probing+0x60/0x60 ? driver_allows_async_probing+0x60/0x60 bus_for_each_drv+0x7b/0xc0 __device_attach+0xbc/0x200 bus_probe_device+0x87/0xa0 device_add+0x404/0x940 ? dev_set_name+0x53/0x70 __auxiliary_device_add+0x43/0x60 add_adev+0x99/0xe0 [mlx5_core] mlx5_attach_device+0xc8/0x120 [mlx5_core] mlx5_load_one_devl_locked+0xb2/0xe0 [mlx5_core] devlink_reload+0x133/0x250 devlink_nl_cmd_reload+0x480/0x570 ? devlink_nl_pre_doit+0x44/0x2b0 genl_family_rcv_msg_doit.isra.0+0xc2/0x110 genl_rcv_msg+0x180/0x2b0 ? devlink_nl_cmd_region_read_dumpit+0x540/0x540 ? devlink_reload+0x250/0x250 ? devlink_put+0x50/0x50 ? genl_family_rcv_msg_doit.isra.0+0x110/0x110 netlink_rcv_skb+0x54/0x100 genl_rcv+0x24/0x40 netlink_unicast+0x1f6/0x2c0 netlink_sendmsg+0x237/0x490 sock_sendmsg+0x33/0x40 __sys_sendto+0x103/0x160 ? handle_mm_fault+0x10e/0x290 ? do_user_addr_fault+0x1c0/0x5f0 __x64_sys_sendto+0x25/0x30 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Fix it by setting port_num to 1 in order to get device status and remove unused variable.
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
Products
linux_kernel

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
NVD-CWE-noinfo

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