# CVE-2023-53419: linux: In the Linux kernel, the following vulnerability has been resolved: rcu: Protect rcu_print_task_exp_stall() ->exp_ta... CVE-2023-53419 is fixed in 20 products on 1 platform, first by ALAS2023-2023-228, released June 21, 2023. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2023-53419 - Priority: Routine - CVSS: 5.5 (medium) - EPSS: 0.0016 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jun 21, 2023 ## Description 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. ] ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | bpftool-debuginfo amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel-debuginfo amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel-debuginfo-common-aarch64 amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel-debuginfo-common-x86_64 amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel-devel amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel-headers amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel-libbpf amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel-libbpf-devel amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel-libbpf-static amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel-livepatch-6.1.34-56.100 amzn 2023 | 1.0-0.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel-tools amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel-tools-debuginfo amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | kernel-tools-devel amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | linux Debian 12.15 (bookworm) | 6.1.37-1 | [DEBIAN-CVE-2023-53419](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53419.md) | Sep 18, 2025 | | Linux | linux Debian 13.5 (trixie) | 6.3.7-1 | [DEBIAN-CVE-2023-53419](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53419.md) | Sep 18, 2025 | | Linux | linux Debian 14 | 6.3.7-1 | [DEBIAN-CVE-2023-53419](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53419.md) | Sep 18, 2025 | | Linux | perf amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | perf-debuginfo amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | python3-perf amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | | Linux | python3-perf-debuginfo amzn 2023 | 6.1.34-56.100.amzn2023 | [ALAS2023-2023-228](https://patchblox.com/security/data/fix/linux/alas2023-2023-228.md) | Jun 21, 2023 | --- Data as of 2026-11-09T13:31:49Z UTC. 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