CVE-2023-53419

/// Technical 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 i

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References