CVE-2026-23353

Published Mar 25, 2026

Last updated 6 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: ice: fix crash in ethtool offline loopback test Since the conversion of ice to page pool, the ethtool loopback test crashes: BUG: kernel NULL pointer dereference, address: 000000000000000c #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 1100f1067 P4D 0 Oops: Oops: 0002 [#1] SMP NOPTI CPU: 23 UID: 0 PID: 5904 Comm: ethtool Kdump: loaded Not tainted 6.19.0-0.rc7.260128g1f97d9dcf5364.49.eln154.x86_64 #1 PREEMPT(lazy) Hardware name: [...] RIP: 0010:ice_alloc_rx_bufs+0x1cd/0x310 [ice] Code: 83 6c 24 30 01 66 41 89 47 08 0f 84 c0 00 00 00 41 0f b7 dc 48 8b 44 24 18 48 c1 e3 04 41 bb 00 10 00 00 48 8d 2c 18 8b 04 24 <89> 45 0c 41 8b 4d 00 49 d3 e3 44 3b 5c 24 24 0f 83 ac fe ff ff 44 RSP: 0018:ff7894738aa1f768 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000700 RDI: 0000000000000000 RBP: 0000000000000000 R08: ff16dcae79880200 R09: 0000000000000019 R10: 0000000000000001 R11: 0000000000001000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ff16dcae6c670000 FS: 00007fcf428850c0(0000) GS:ff16dcb149710000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000000c CR3: 0000000121227005 CR4: 0000000000773ef0 PKRU: 55555554 Call Trace: <TASK> ice_vsi_cfg_rxq+0xca/0x460 [ice] ice_vsi_cfg_rxqs+0x54/0x70 [ice] ice_loopback_test+0xa9/0x520 [ice] ice_self_test+0x1b9/0x280 [ice] ethtool_self_test+0xe5/0x200 __dev_ethtool+0x1106/0x1a90 dev_ethtool+0xbe/0x1a0 dev_ioctl+0x258/0x4c0 sock_do_ioctl+0xe3/0x130 __x64_sys_ioctl+0xb9/0x100 do_syscall_64+0x7c/0x700 entry_SYSCALL_64_after_hwframe+0x76/0x7e [...] It crashes because we have not initialized libeth for the rx ring. Fix it by treating ICE_VSI_LB VSIs slightly more like normal PF VSIs and letting them have a q_vector. It's just a dummy, because the loopback test does not use interrupts, but it contains a napi struct that can be passed to libeth_rx_fq_create() called from ice_vsi_cfg_rxq() -> ice_rxq_pp_create().
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
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
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