CVE-2023-53419: In the Linux kernel, the following vulnerability has been resolved: rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access For kernels built with…

PriorityP419medium5.5CVSS 3.1

AVLACLPRLUINSUCNINAH

EPSS

0.14%

4.2th percentile

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. ]

Affected

15 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 6.1.37-1 (bookworm)	linux 6.1.37-1 (bookworm)
linux	linux	—	—
linux	linux	>= 314eeb43e5f22856b281c91c966e51e5782a3498 < a7d21b8585894e6fff973f6ddae42f02b13f600f	a7d21b8585894e6fff973f6ddae42f02b13f600f
linux	linux	>= 314eeb43e5f22856b281c91c966e51e5782a3498 < e30a55e98ae6c44253d8b129efefd5da5bc6e3bc	e30a55e98ae6c44253d8b129efefd5da5bc6e3bc
linux	linux	>= 314eeb43e5f22856b281c91c966e51e5782a3498 < d0a8c0e31a09ec1efd53079083e2a677956b4d91	d0a8c0e31a09ec1efd53079083e2a677956b4d91
linux	linux	>= 314eeb43e5f22856b281c91c966e51e5782a3498 < 2bc0ae94ef1f9ed322d8ee439de3239ea3632ab2	2bc0ae94ef1f9ed322d8ee439de3239ea3632ab2
linux	linux	>= 314eeb43e5f22856b281c91c966e51e5782a3498 < 3c1566bca3f8349f12b75d0a2d5e4a20ad6262ec	3c1566bca3f8349f12b75d0a2d5e4a20ad6262ec
linux	linux_kernel	< 5.10.181	5.10.181
linux	linux_kernel	>= 0 < 5.10.191-1	5.10.191-1
linux	linux_kernel	>= 0 < 6.1.37-1	6.1.37-1
linux	linux_kernel	>= 0 < 6.3.7-1	6.3.7-1
linux	linux_kernel	>= 0 < 6.3.7-1	6.3.7-1
linux	linux_kernel	>= 5.11 < 5.15.113	5.15.113
linux	linux_kernel	>= 5.16 < 6.1.30	6.1.30
linux	linux_kernel	>= 6.2 < 6.3.4	6.3.4

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

osv5.5MEDIUM

vendor_debian5.5MEDIUM

vendor_redhat5.5MEDIUM

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