CVE-2026-43449: nvme-pci: Fix slab-out-of-bounds in nvme_dbbuf_set

CVE-2026-43449: nvme-pci: Fix slab-out-of-bounds in nvme_dbbuf_set

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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 0000000000000000 dead000000000001
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 000fffffc0000003 ffffea0000164a01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88800592a400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88800592a480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88800592a500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                             ^
 ffff88800592a580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88800592a600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

The Linux kernel CVE team has assigned CVE-2026-43449 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.10 with commit 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf and fixed in 5.10.253 with commit 2b9d605c3f0d3262142f196249cd3bd58c857c71
	Issue introduced in 5.10 with commit 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf and fixed in 5.15.203 with commit 86183d550559e45e07059bbdf17331fea469e38c
	Issue introduced in 5.10 with commit 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf and fixed in 6.1.167 with commit d7990c936e25f484b61a5adeeadc1d290a9fd16e
	Issue introduced in 5.10 with commit 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf and fixed in 6.6.130 with commit 83e6edd6358326c9c2de31a54bb4a1ec50703f1f
	Issue introduced in 5.10 with commit 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf and fixed in 6.12.78 with commit 50bad78f03a02d3c0f228edf9912b494d3e7acb9
	Issue introduced in 5.10 with commit 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf and fixed in 6.18.19 with commit 328c551f0cc81ee776b186b86cc6e5253bb6fda7
	Issue introduced in 5.10 with commit 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf and fixed in 6.19.9 with commit 78279d2d74c58a0ed64e43cf601a02649771182e
	Issue introduced in 5.10 with commit 0f0d2c876c96d4908a9ef40959a44bec21bdd6cf and fixed in 7.0 with commit b4e78f1427c7d6859229ae9616df54e1fc05a516
	Issue introduced in 4.14.210 with commit 930bb3092fe606baa23d57ae59b70b291d67a8af
	Issue introduced in 4.19.161 with commit fd1c1de8c4589fdd528733bfd01ed0c5f3f69204
	Issue introduced in 5.4.81 with commit 4940816604e3ce7e05e8df297773ee86c0476d48
	Issue introduced in 5.9.12 with commit 55a3b1ad694631cc2698b5500ac5865d7d0f064e

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-43449
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/nvme/host/pci.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/2b9d605c3f0d3262142f196249cd3bd58c857c71
	https://git.kernel.org/stable/c/86183d550559e45e07059bbdf17331fea469e38c
	https://git.kernel.org/stable/c/d7990c936e25f484b61a5adeeadc1d290a9fd16e
	https://git.kernel.org/stable/c/83e6edd6358326c9c2de31a54bb4a1ec50703f1f
	https://git.kernel.org/stable/c/50bad78f03a02d3c0f228edf9912b494d3e7acb9
	https://git.kernel.org/stable/c/328c551f0cc81ee776b186b86cc6e5253bb6fda7
	https://git.kernel.org/stable/c/78279d2d74c58a0ed64e43cf601a02649771182e
	https://git.kernel.org/stable/c/b4e78f1427c7d6859229ae9616df54e1fc05a516