CVE-2026-43449

Published May 8, 2026

Last updated 5 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: nvme-pci: Fix slab-out-of-bounds in nvme_dbbuf_set dev->online_queues is a count incremented in nvme_init_queue. Thus, valid indices are 0 through dev->online_queues − 1. This patch fixes the loop condition to ensure the index stays within the valid range. Index 0 is excluded because it is the admin queue. KASAN splat: ================================================================== BUG: KASAN: slab-out-of-bounds in nvme_dbbuf_free drivers/nvme/host/pci.c:377 [inline] BUG: KASAN: slab-out-of-bounds in nvme_dbbuf_set+0x39c/0x400 drivers/nvme/host/pci.c:404 Read of size 2 at addr ffff88800592a574 by task kworker/u8:5/74 CPU: 0 UID: 0 PID: 74 Comm: kworker/u8:5 Not tainted 6.19.0-dirty #10 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 Workqueue: nvme-reset-wq nvme_reset_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xea/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xce/0x5d0 mm/kasan/report.c:482 kasan_report+0xdc/0x110 mm/kasan/report.c:595 __asan_report_load2_noabort+0x18/0x20 mm/kasan/report_generic.c:379 nvme_dbbuf_free drivers/nvme/host/pci.c:377 [inline] nvme_dbbuf_set+0x39c/0x400 drivers/nvme/host/pci.c:404 nvme_reset_work+0x36b/0x8c0 drivers/nvme/host/pci.c:3252 process_one_work+0x956/0x1aa0 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x65c/0xe60 kernel/workqueue.c:3421 kthread+0x41a/0x930 kernel/kthread.c:463 ret_from_fork+0x6f8/0x8c0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 </TASK> Allocated by task 34 on cpu 1 at 4.241550s: kasan_save_stack+0x2c/0x60 mm/kasan/common.c:57 kasan_save_track+0x1c/0x70 mm/kasan/common.c:78 kasan_save_alloc_info+0x3c/0x50 mm/kasan/generic.c:570 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xb5/0xc0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kmalloc_node_noprof+0x2bf/0x8d0 mm/slub.c:5663 kmalloc_array_node_noprof include/linux/slab.h:1075 [inline] nvme_pci_alloc_dev drivers/nvme/host/pci.c:3479 [inline] nvme_probe+0x2f1/0x1820 drivers/nvme/host/pci.c:3534 local_pci_probe+0xef/0x1c0 drivers/pci/pci-driver.c:324 pci_call_probe drivers/pci/pci-driver.c:392 [inline] __pci_device_probe drivers/pci/pci-driver.c:417 [inline] pci_device_probe+0x743/0x920 drivers/pci/pci-driver.c:451 call_driver_probe drivers/base/dd.c:583 [inline] really_probe+0x29b/0xb70 drivers/base/dd.c:661 __driver_probe_device+0x3b0/0x4a0 drivers/base/dd.c:803 driver_probe_device+0x56/0x1f0 drivers/base/dd.c:833 __driver_attach_async_helper+0x155/0x340 drivers/base/dd.c:1159 async_run_entry_fn+0xa6/0x4b0 kernel/async.c:129 process_one_work+0x956/0x1aa0 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x65c/0xe60 kernel/workqueue.c:3421 kthread+0x41a/0x930 kernel/kthread.c:463 ret_from_fork+0x6f8/0x8c0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 The buggy address belongs to the object at ffff88800592a000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 244 bytes to the right of allocated 1152-byte region [ffff88800592a000, ffff88800592a480) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5928 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfffffc0000040(head|node=0|zone=1|lastcpupid=0x1fffff) page_type: f5(slab) raw: 000fffffc0000040 ffff888001042000 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 000fffffc0000040 ffff888001042000 00000 ---truncated---
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
7.1
Impact score
5.2
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Severity
HIGH

Weaknesses

nvd@nist.gov
CWE-125

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