ghsa-w2v8-x9hv-74wh
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access
For kernels built with CONFIG_PREEMPT_RCU=y, the following scenario can result in a NULL-pointer dereference:
CPU1 CPU2
rcu_preempt_deferred_qs_irqrestore rcu_print_task_exp_stall if (special.b.blocked) READ_ONCE(rnp->exp_tasks) != NULL raw_spin_lock_rcu_node np = rcu_next_node_entry(t, rnp) if (&t->rcu_node_entry == rnp->exp_tasks) WRITE_ONCE(rnp->exp_tasks, np) .... raw_spin_unlock_irqrestore_rcu_node raw_spin_lock_irqsave_rcu_node t = list_entry(rnp->exp_tasks->prev, struct task_struct, rcu_node_entry) (if rnp->exp_tasks is NULL, this will dereference a NULL pointer)
The problem is that CPU2 accesses the rcu_node structure's->exp_tasks field without holding the rcu_node structure's ->lock and CPU2 did not observe CPU1's change to rcu_node structure's ->exp_tasks in time. Therefore, if CPU1 sets rcu_node structure's->exp_tasks pointer to NULL, then CPU2 might dereference that NULL pointer.
This commit therefore holds the rcu_node structure's ->lock while accessing that structure's->exp_tasks field.
[ paulmck: Apply Frederic Weisbecker feedback. ]
{
"affected": [],
"aliases": [
"CVE-2023-53419"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-09-18T16:15:45Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nrcu: Protect rcu_print_task_exp_stall() -\u003eexp_tasks access\n\nFor kernels built with CONFIG_PREEMPT_RCU=y, the following scenario can\nresult in a NULL-pointer dereference:\n\n CPU1 CPU2\nrcu_preempt_deferred_qs_irqrestore rcu_print_task_exp_stall\n if (special.b.blocked) READ_ONCE(rnp-\u003eexp_tasks) != NULL\n raw_spin_lock_rcu_node\n np = rcu_next_node_entry(t, rnp)\n if (\u0026t-\u003ercu_node_entry == rnp-\u003eexp_tasks)\n WRITE_ONCE(rnp-\u003eexp_tasks, np)\n ....\n raw_spin_unlock_irqrestore_rcu_node\n raw_spin_lock_irqsave_rcu_node\n t = list_entry(rnp-\u003eexp_tasks-\u003eprev,\n struct task_struct, rcu_node_entry)\n (if rnp-\u003eexp_tasks is NULL, this\n will dereference a NULL pointer)\n\nThe problem is that CPU2 accesses the rcu_node structure\u0027s-\u003eexp_tasks\nfield without holding the rcu_node structure\u0027s -\u003elock and CPU2 did\nnot observe CPU1\u0027s change to rcu_node structure\u0027s -\u003eexp_tasks in time.\nTherefore, if CPU1 sets rcu_node structure\u0027s-\u003eexp_tasks pointer to NULL,\nthen CPU2 might dereference that NULL pointer.\n\nThis commit therefore holds the rcu_node structure\u0027s -\u003elock while\naccessing that structure\u0027s-\u003eexp_tasks field.\n\n[ paulmck: Apply Frederic Weisbecker feedback. ]",
"id": "GHSA-w2v8-x9hv-74wh",
"modified": "2025-09-18T18:30:27Z",
"published": "2025-09-18T18:30:27Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-53419"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2bc0ae94ef1f9ed322d8ee439de3239ea3632ab2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3c1566bca3f8349f12b75d0a2d5e4a20ad6262ec"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a7d21b8585894e6fff973f6ddae42f02b13f600f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d0a8c0e31a09ec1efd53079083e2a677956b4d91"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e30a55e98ae6c44253d8b129efefd5da5bc6e3bc"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.