# CVE-2026-23244: nvme: fix memory allocation in nvme_pr_read_keys()

> A local attacker can trigger a kernel warning and potential denial of service by passing a large num_keys value to the NVMe persistent reservation read keys function.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Mar 2026
- **Updated:** 11 May 2026
- **Also known as:** AZL-79998, BELL-CVE-2026-23244, DEBIAN-CVE-2026-23244, GHSA-h4w6-67wq-xf89, ROOT-OS-DEBIAN-13-CVE-2026-23244, ROOT-OS-UBUNTU-2404-CVE-2026-23244, UBUNTU-CVE-2026-23244

## What is CVE-2026-23244?

CVE-2026-23244 is a high-severity denial of service vulnerability in Linux kernel, published on 18 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

nvme: fix memory allocation in nvme_pr_read_keys()

nvme_pr_read_keys() takes num_keys from userspace and uses it to
calculate the allocation size for rse via struct_size(). The upper
limit is PR_KEYS_MAX (64K).

A malicious or buggy userspace can pass a large num_keys value that
results in a 4MB allocation attempt at most, causing a warning in
the page allocator when the order exceeds MAX_PAGE_ORDER.

To fix this, use kvzalloc() instead of kzalloc().

This bug has the same reasoning and fix with the patch below:
https://lore.kernel.org/linux-block/20251212013510.3576091-1-kartikey406@gmail.com/

Warning log:
WARNING: mm/page_alloc.c:5216 at __alloc_frozen_pages_noprof+0x5aa/0x2300 mm/page_alloc.c:5216, CPU#1: syz-executor117/272
Modules linked in:
CPU: 1 UID: 0 PID: 272 Comm: syz-executor117 Not tainted 6.19.0 #1 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
RIP: 0010:__alloc_frozen_pages_noprof+0x5aa/0x2300 mm/page_alloc.c:5216
Code: ff 83 bd a8 fe ff ff 0a 0f 86 69 fb ff ff 0f b6 1d f9 f9 c4 04 80 fb 01 0f 87 3b 76 30 ff 83 e3 01 75 09 c6 05 e4 f9 c4 04 01 <0f> 0b 48 c7 85 70 fe ff ff 00 00 00 00 e9 8f fd ff ff 31 c0 e9 0d
RSP: 0018:ffffc90000fcf450 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffff920001f9ea0
RDX: 0000000000000000 RSI: 000000000000000b RDI: 0000000000040dc0
RBP: ffffc90000fcf648 R08: ffff88800b6c3380 R09: 0000000000000001
R10: ffffc90000fcf840 R11: ffff88807ffad280 R12: 0000000000000000
R13: 0000000000040dc0 R14: 0000000000000001 R15: ffffc90000fcf620
FS:  0000555565db33c0(0000) GS:ffff8880be26c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000000c CR3: 0000000003b72000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 alloc_pages_mpol+0x236/0x4d0 mm/mempolicy.c:2486
 alloc_frozen_pages_noprof+0x149/0x180 mm/mempolicy.c:2557
 ___kmalloc_large_node+0x10c/0x140 mm/slub.c:5598
 __kmalloc_large_node_noprof+0x25/0xc0 mm/slub.c:5629
 __do_kmalloc_node mm/slub.c:5645 [inline]
 __kmalloc_noprof+0x483/0x6f0 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 nvme_pr_read_keys+0x8f/0x4c0 drivers/nvme/host/pr.c:245
 blkdev_pr_read_keys block/ioctl.c:456 [inline]
 blkdev_common_ioctl+0x1b71/0x29b0 block/ioctl.c:730
 blkdev_ioctl+0x299/0x700 block/ioctl.c:786
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x1bf/0x220 fs/ioctl.c:583
 x64_sys_call+0x1280/0x21b0 mnt/fuzznvme_1/fuzznvme/linux-build/v6.19/./arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x71/0x330 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fb893d3108d
Code: 28 c3 e8 46 1e 00 00 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffff61f2f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffff61f3138 RCX: 00007fb893d3108d
RDX: 0000000020000040 RSI: 00000000c01070ce RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000000 R09: 00007ffff61f3138
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffff61f3128 R14: 00007fb893dae530 R15: 0000000000000001
 </TASK>

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-23244?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23244?

Apply the vendor's patch.

## Is CVE-2026-23244 being exploited?

There is no known exploitation of CVE-2026-23244 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23244 and fix it if it is affected.

What it is: CVE-2026-23244 is a high-severity denial of service vulnerability in Linux kernel, published on 18 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-23244 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-23244/ (Markdown: https://insights.sbomify.com/CVE-2026-23244/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23244
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23244
- OSV: https://osv.dev/vulnerability/CVE-2026-23244

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23244/
Summaries are generated and may contain mistakes; the official description above is the record.