CVE-2024-58100

Published May 5, 2025

Last updated 8 days ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: bpf: check changes_pkt_data property for extension programs When processing calls to global sub-programs, verifier decides whether to invalidate all packet pointers in current state depending on the changes_pkt_data property of the global sub-program. Because of this, an extension program replacing a global sub-program must be compatible with changes_pkt_data property of the sub-program being replaced. This commit: - adds changes_pkt_data flag to struct bpf_prog_aux: - this flag is set in check_cfg() for main sub-program; - in jit_subprogs() for other sub-programs; - modifies bpf_check_attach_btf_id() to check changes_pkt_data flag; - moves call to check_attach_btf_id() after the call to check_cfg(), because it needs changes_pkt_data flag to be set: bpf_check: ... ... - check_attach_btf_id resolve_pseudo_ldimm64 resolve_pseudo_ldimm64 --> bpf_prog_is_offloaded bpf_prog_is_offloaded check_cfg check_cfg + check_attach_btf_id ... ... The following fields are set by check_attach_btf_id(): - env->ops - prog->aux->attach_btf_trace - prog->aux->attach_func_name - prog->aux->attach_func_proto - prog->aux->dst_trampoline - prog->aux->mod - prog->aux->saved_dst_attach_type - prog->aux->saved_dst_prog_type - prog->expected_attach_type Neither of these fields are used by resolve_pseudo_ldimm64() or bpf_prog_offload_verifier_prep() (for netronome and netdevsim drivers), so the reordering is safe.
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