{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2023-53419",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2023-53419"
  ],
  "published": "2025-09-18T16:08:26Z",
  "summary": "rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nrcu: Protect rcu_print_task_exp_stall() ->exp_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->exp_tasks) != NULL\n    raw_spin_lock_rcu_node\n    np = rcu_next_node_entry(t, rnp)\n    if (&t->rcu_node_entry == rnp->exp_tasks)\n      WRITE_ONCE(rnp->exp_tasks, np)\n      ....\n      raw_spin_unlock_irqrestore_rcu_node\n                                                    raw_spin_lock_irqsave_rcu_node\n                                                    t = list_entry(rnp->exp_tasks->prev,\n                                                        struct task_struct, rcu_node_entry)\n                                                    (if rnp->exp_tasks is NULL, this\n                                                       will dereference a NULL pointer)\n\nThe problem is that CPU2 accesses the rcu_node structure's->exp_tasks\nfield without holding the rcu_node structure's ->lock and CPU2 did\nnot observe CPU1's change to rcu_node structure's ->exp_tasks in time.\nTherefore, if CPU1 sets rcu_node structure's->exp_tasks pointer to NULL,\nthen CPU2 might dereference that NULL pointer.\n\nThis commit therefore holds the rcu_node structure's ->lock while\naccessing that structure's->exp_tasks field.\n\n[ paulmck: Apply Frederic Weisbecker feedback. ]",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.21-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v7",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v7l",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v8",
            "binary_version": "1:6.1.21-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.21-1+rpt1": {
            "linux_commit": "0afb5e98488aed7017b9bf321b575d0177feb7ed",
            "upstream_version": "6.1.21",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.30"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2023-53419"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a7d21b8585894e6fff973f6ddae42f02b13f600f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e30a55e98ae6c44253d8b129efefd5da5bc6e3bc"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d0a8c0e31a09ec1efd53079083e2a677956b4d91"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2bc0ae94ef1f9ed322d8ee439de3239ea3632ab2"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3c1566bca3f8349f12b75d0a2d5e4a20ad6262ec"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-12T04:54:46Z"
  }
}