{"id":"DEBIAN-CVE-2023-53419","details":"In the Linux kernel, the following vulnerability has been resolved:  rcu: Protect rcu_print_task_exp_stall() -\u003eexp_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-\u003eexp_tasks) != NULL     raw_spin_lock_rcu_node     np = rcu_next_node_entry(t, rnp)     if (&t-\u003ercu_node_entry == rnp-\u003eexp_tasks)       WRITE_ONCE(rnp-\u003eexp_tasks, np)       ....       raw_spin_unlock_irqrestore_rcu_node                                                     raw_spin_lock_irqsave_rcu_node                                                     t = list_entry(rnp-\u003eexp_tasks-\u003eprev,                                                         struct task_struct, rcu_node_entry)                                                     (if rnp-\u003eexp_tasks is NULL, this                                                        will dereference a NULL pointer)  The problem is that CPU2 accesses the rcu_node structure's-\u003eexp_tasks field without holding the rcu_node structure's -\u003elock and CPU2 did not observe CPU1's change to rcu_node structure's -\u003eexp_tasks in time. Therefore, if CPU1 sets rcu_node structure's-\u003eexp_tasks pointer to NULL, then CPU2 might dereference that NULL pointer.  This commit therefore holds the rcu_node structure's -\u003elock while accessing that structure's-\u003eexp_tasks field.  [ paulmck: Apply Frederic Weisbecker feedback. ]","modified":"2026-09-15T09:02:51.110734079Z","published":"2025-09-18T16:15:45.650Z","upstream":["CVE-2023-53419"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2023-53419"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.37-1"}]}],"versions":["6.1.27-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-53419.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.3.7-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-53419.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.3.7-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-53419.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}