CVE-2023-53342

Published Sep 17, 2025

Last updated 9 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: net: marvell: prestera: fix handling IPv4 routes with nhid Fix handling IPv4 routes referencing a nexthop via its id by replacing calls to fib_info_nh() with fib_info_nhc(). Trying to add an IPv4 route referencing a nextop via nhid: $ ip link set up swp5 $ ip a a 10.0.0.1/24 dev swp5 $ ip nexthop add dev swp5 id 20 via 10.0.0.2 $ ip route add 10.0.1.0/24 nhid 20 triggers warnings when trying to handle the route: [ 528.805763] ------------[ cut here ]------------ [ 528.810437] WARNING: CPU: 3 PID: 53 at include/net/nexthop.h:468 __prestera_fi_is_direct+0x2c/0x68 [prestera] [ 528.820434] Modules linked in: prestera_pci act_gact act_police sch_ingress cls_u32 cls_flower prestera arm64_delta_tn48m_dn_led(O) arm64_delta_tn48m_dn_cpld(O) [last unloaded: prestera_pci] [ 528.837485] CPU: 3 PID: 53 Comm: kworker/u8:3 Tainted: G O 6.4.5 #1 [ 528.845178] Hardware name: delta,tn48m-dn (DT) [ 528.849641] Workqueue: prestera_ordered __prestera_router_fib_event_work [prestera] [ 528.857352] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 528.864347] pc : __prestera_fi_is_direct+0x2c/0x68 [prestera] [ 528.870135] lr : prestera_k_arb_fib_evt+0xb20/0xd50 [prestera] [ 528.876007] sp : ffff80000b20bc90 [ 528.879336] x29: ffff80000b20bc90 x28: 0000000000000000 x27: ffff0001374d3a48 [ 528.886510] x26: ffff000105604000 x25: ffff000134af8a28 x24: ffff0001374d3800 [ 528.893683] x23: ffff000101c89148 x22: ffff000101c89000 x21: ffff000101c89200 [ 528.900855] x20: ffff00013641fda0 x19: ffff800009d01088 x18: 0000000000000059 [ 528.908027] x17: 0000000000000277 x16: 0000000000000000 x15: 0000000000000000 [ 528.915198] x14: 0000000000000003 x13: 00000000000fe400 x12: 0000000000000000 [ 528.922371] x11: 0000000000000002 x10: 0000000000000aa0 x9 : ffff8000013d2020 [ 528.929543] x8 : 0000000000000018 x7 : 000000007b1703f8 x6 : 000000001ca72f86 [ 528.936715] x5 : 0000000033399ea7 x4 : 0000000000000000 x3 : ffff0001374d3acc [ 528.943886] x2 : 0000000000000000 x1 : ffff00010200de00 x0 : ffff000134ae3f80 [ 528.951058] Call trace: [ 528.953516] __prestera_fi_is_direct+0x2c/0x68 [prestera] [ 528.958952] __prestera_router_fib_event_work+0x100/0x158 [prestera] [ 528.965348] process_one_work+0x208/0x488 [ 528.969387] worker_thread+0x4c/0x430 [ 528.973068] kthread+0x120/0x138 [ 528.976313] ret_from_fork+0x10/0x20 [ 528.979909] ---[ end trace 0000000000000000 ]--- [ 528.984998] ------------[ cut here ]------------ [ 528.989645] WARNING: CPU: 3 PID: 53 at include/net/nexthop.h:468 __prestera_fi_is_direct+0x2c/0x68 [prestera] [ 528.999628] Modules linked in: prestera_pci act_gact act_police sch_ingress cls_u32 cls_flower prestera arm64_delta_tn48m_dn_led(O) arm64_delta_tn48m_dn_cpld(O) [last unloaded: prestera_pci] [ 529.016676] CPU: 3 PID: 53 Comm: kworker/u8:3 Tainted: G W O 6.4.5 #1 [ 529.024368] Hardware name: delta,tn48m-dn (DT) [ 529.028830] Workqueue: prestera_ordered __prestera_router_fib_event_work [prestera] [ 529.036539] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 529.043533] pc : __prestera_fi_is_direct+0x2c/0x68 [prestera] [ 529.049318] lr : __prestera_k_arb_fc_apply+0x280/0x2f8 [prestera] [ 529.055452] sp : ffff80000b20bc60 [ 529.058781] x29: ffff80000b20bc60 x28: 0000000000000000 x27: ffff0001374d3a48 [ 529.065953] x26: ffff000105604000 x25: ffff000134af8a28 x24: ffff0001374d3800 [ 529.073126] x23: ffff000101c89148 x22: ffff000101c89148 x21: ffff00013641fda0 [ 529.080299] x20: ffff000101c89000 x19: ffff000101c89020 x18: 0000000000000059 [ 529.087471] x17: 0000000000000277 x16: 0000000000000000 x15: 0000000000000000 [ 529.094642] x14: 0000000000000003 x13: 00000000000fe400 x12: 0000000000000000 [ 529.101814] x11: 0000000000000002 x10: 0000000000000aa0 x9 : ffff8000013cee80 [ 529.108985] x8 : 0000000000000018 x7 : 000000007b1703f8 x6 ---truncated---
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