CVE-2023-53056

Published May 2, 2025

Last updated a year ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Synchronize the IOCB count to be in order A system hang was observed with the following call trace: BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 15 PID: 86747 Comm: nvme Kdump: loaded Not tainted 6.2.0+ #1 Hardware name: Dell Inc. PowerEdge R6515/04F3CJ, BIOS 2.7.3 03/31/2022 RIP: 0010:__wake_up_common+0x55/0x190 Code: 41 f6 01 04 0f 85 b2 00 00 00 48 8b 43 08 4c 8d 40 e8 48 8d 43 08 48 89 04 24 48 89 c6\ 49 8d 40 18 48 39 c6 0f 84 e9 00 00 00 <49> 8b 40 18 89 6c 24 14 31 ed 4c 8d 60 e8 41 8b 18 f6 c3 04 75 5d RSP: 0018:ffffb05a82afbba0 EFLAGS: 00010082 RAX: 0000000000000000 RBX: ffff8f9b83a00018 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffff8f9b83a00020 RDI: ffff8f9b83a00018 RBP: 0000000000000001 R08: ffffffffffffffe8 R09: ffffb05a82afbbf8 R10: 70735f7472617473 R11: 5f30307832616c71 R12: 0000000000000001 R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f815cf4c740(0000) GS:ffff8f9eeed80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000010633a000 CR4: 0000000000350ee0 Call Trace: <TASK> __wake_up_common_lock+0x83/0xd0 qla_nvme_ls_req+0x21b/0x2b0 [qla2xxx] __nvme_fc_send_ls_req+0x1b5/0x350 [nvme_fc] nvme_fc_xmt_disconnect_assoc+0xca/0x110 [nvme_fc] nvme_fc_delete_association+0x1bf/0x220 [nvme_fc] ? nvme_remove_namespaces+0x9f/0x140 [nvme_core] nvme_do_delete_ctrl+0x5b/0xa0 [nvme_core] nvme_sysfs_delete+0x5f/0x70 [nvme_core] kernfs_fop_write_iter+0x12b/0x1c0 vfs_write+0x2a3/0x3b0 ksys_write+0x5f/0xe0 do_syscall_64+0x5c/0x90 ? syscall_exit_work+0x103/0x130 ? syscall_exit_to_user_mode+0x12/0x30 ? do_syscall_64+0x69/0x90 ? exit_to_user_mode_loop+0xd0/0x130 ? exit_to_user_mode_prepare+0xec/0x100 ? syscall_exit_to_user_mode+0x12/0x30 ? do_syscall_64+0x69/0x90 ? syscall_exit_to_user_mode+0x12/0x30 ? do_syscall_64+0x69/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7f815cd3eb97 The IOCB counts are out of order and that would block any commands from going out and subsequently hang the system. Synchronize the IOCB count to be in correct order.
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-476

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: cgroup: Avoid iteration of dying tasks with zero refcount The commit 260fbcb92bbea ("cgroup: Move dying_tasks cleanup from cgroup_task_release() to cgroup_task_free()") extended the lifetime of tasks on the dying_tasks list. The iterators have provision to go through dying_tasks because of dying threadgroup leaders or explicit CSS_TASK_ITER_WITH_DEAD, however, it was expected that such tasks can obtain a new reference (that is possible before cgroup_task_release()/put_task_struct_rcu_user()). The tasks after cgroup_task_release() and before cgroup_task_free() are subject to race when they may or may not have ->usage count > 0. The race window is between css_task_iter_next() invocations when css_set_lock is released and we may arrive at a new ->task_pos. The iterator should not attempt to resurrect tasks whose ->usage count dropped to zero. (When that happens, __put_task_struct_rcu_cb() is already imminent and the returned task_struct would could be used after free.) As for the fix, we cannot simply check the signal->live count of a task on the dying list because that won't distinguish regular zombies waiting to be reaped from RCU remnant tasks that are going to be free'd. Therefore add an extra check to rule out ->usage==0 tasks from any iteration. The repeat: loop in css_task_iter_advance() doesn't consider ->usage count, so add a new loop to css_task_iter_next() to skip de-used tasks on the dying_list. Rough illustration of the possible race R (reader of cgroup.procs) T (thread) L (group leader) --------------------------------- -------------------------------- -------------------------------- L exits, signal->live > 0 cgroup_task_dead(L) css_set_skip_task_iters() // skips only cset->tasks list_add_tail(&L->cg_list, &cset->dying_tasks) css_task_iter_next() take css_set_lock css_task_iter_advance() leader && signal->live != 0 => it->task_pos = &L->cg_list release css_set_lock T exits --signal->live == 0 cgroup_task_dead(T) // css_set_lock release_task(T) cgroup_task_release(T) release_task(L) // zap_leader cgroup_task_release(L) put_task_struct_rcu_user(L) ...RCU... put_task_struct(L) L->usage = 0 /* L still on dying_tasks */ ...RCU... __put_task_struct(L) css_task_iter_next() // another iteration take css_set_lock it->task_pos = &L->cg_list get_task_struct(L) => addition on 0 drop css_set_lock cgroup_task_free(L) css_set_skip_task_iters() // dying skip comes too late free_task(L) cgroup_procs_show() task_pid_vnr(L)•CVE-2026-98163