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

High 7.1 Published 18 Mar 2026 Updated 11 May 2026

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.

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

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/[email protected]/

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

Which versions are affected by CVE-2026-23244?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-23244?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-23244 being exploited?

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

All Linux kernel vulnerabilities

Sources

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 and 1 more.