CVE-2022-50129

Published Jun 18, 2025

Last updated 3 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: RDMA/srpt: Fix a use-after-free Change the LIO port members inside struct srpt_port from regular members into pointers. Allocate the LIO port data structures from inside srpt_make_tport() and free these from inside srpt_make_tport(). Keep struct srpt_device as long as either an RDMA port or a LIO target port is associated with it. This patch decouples the lifetime of struct srpt_port (controlled by the RDMA core) and struct srpt_port_id (controlled by LIO). This patch fixes the following KASAN complaint: BUG: KASAN: use-after-free in srpt_enable_tpg+0x31/0x70 [ib_srpt] Read of size 8 at addr ffff888141cc34b8 by task check/5093 Call Trace: <TASK> show_stack+0x4e/0x53 dump_stack_lvl+0x51/0x66 print_address_description.constprop.0.cold+0xea/0x41e print_report.cold+0x90/0x205 kasan_report+0xb9/0xf0 __asan_load8+0x69/0x90 srpt_enable_tpg+0x31/0x70 [ib_srpt] target_fabric_tpg_base_enable_store+0xe2/0x140 [target_core_mod] configfs_write_iter+0x18b/0x210 new_sync_write+0x1f2/0x2f0 vfs_write+0x3e3/0x540 ksys_write+0xbb/0x140 __x64_sys_write+0x42/0x50 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 </TASK>
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
7.8
Impact score
5.9
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity
HIGH

Weaknesses

nvd@nist.gov
CWE-416

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