{"id":"CVE-2023-53419","summary":"rcu: Protect rcu_print_task_exp_stall() -\u003eexp_tasks access","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 (&t-\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's-\u003eexp_tasks\nfield without holding the rcu_node structure's -\u003elock and CPU2 did\nnot observe CPU1's change to rcu_node structure's -\u003eexp_tasks in time.\nTherefore, if CPU1 sets rcu_node structure's-\u003eexp_tasks pointer to NULL,\nthen CPU2 might dereference that NULL pointer.\n\nThis commit therefore holds the rcu_node structure's -\u003elock while\naccessing that structure's-\u003eexp_tasks field.\n\n[ paulmck: Apply Frederic Weisbecker feedback. ]","modified":"2026-04-02T09:44:10.560343Z","published":"2025-09-18T16:04:02.955Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53419.json"},"references":[{"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"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53419.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53419"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"314eeb43e5f22856b281c91c966e51e5782a3498"},{"fixed":"a7d21b8585894e6fff973f6ddae42f02b13f600f"},{"fixed":"e30a55e98ae6c44253d8b129efefd5da5bc6e3bc"},{"fixed":"d0a8c0e31a09ec1efd53079083e2a677956b4d91"},{"fixed":"2bc0ae94ef1f9ed322d8ee439de3239ea3632ab2"},{"fixed":"3c1566bca3f8349f12b75d0a2d5e4a20ad6262ec"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-53419.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}