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Linux EUVDEUVD-2026-12805

| CVE-2026-23244 HIGH
Out-of-bounds Read (CWE-125)
2026-03-18 Linux
High
Disputed · 7.1 NVD
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Severity by source

Sources disagree (Low–High)
NVD PRIMARY
7.1 HIGH
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
SUSE
HIGH
qualitative
Red Hat
5.5 LOW
qualitative

vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.

CVSS VectorNVD

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High

Lifecycle Timeline

6
Re-analysis Queued
May 21, 2026 - 16:07 vuln.today
cvss_changed
CVSS changed
May 21, 2026 - 16:07 NVD
7.1 (HIGH)
Patch released
Mar 31, 2026 - 21:13 nvd
Patch available
EUVD ID Assigned
Mar 18, 2026 - 10:30 euvd
EUVD-2026-12805
Analysis Generated
Mar 18, 2026 - 10:30 vuln.today
CVE Published
Mar 18, 2026 - 10:05 nvd
N/A

DescriptionCVE.org

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>

AnalysisAI

A memory allocation vulnerability exists in the Linux kernel's NVMe Persistent Reservation implementation where the nvme_pr_read_keys() function fails to properly handle large num_keys values passed from userspace, resulting in excessive memory allocation attempts up to 4MB that trigger page allocator warnings and potential denial of service. This affects Linux kernel versions across multiple stable branches (6.5, 6.12.77, 6.18.17, 6.19.7, and 7.0-rc3) and requires local access with ioctl privileges to trigger. The vulnerability is addressed through replacement of kzalloc() with kvzalloc() to support larger allocations via vmalloc fallback, and patches are available across multiple kernel stable branches.

Technical ContextAI

The vulnerability resides in the Linux kernel's NVMe driver subsystem, specifically in the block layer's Persistent Reservation (PR) implementation accessed via the blkdev_ioctl interface. The affected code path is drivers/nvme/host/pr.c in the nvme_pr_read_keys() function, which accepts user-controlled num_keys parameter and calculates allocation size using struct_size() with an upper limit of PR_KEYS_MAX (65536). The root cause is CWE-400 (Uncontrolled Resource Consumption) combined with improper memory allocation strategy: kzalloc() uses only the slab allocator and fails with warnings when requested orders exceed MAX_PAGE_ORDER (typically order 10 on x86, limiting contiguous allocations to ~4MB), whereas kvzalloc() automatically falls back to vmalloc() for larger requests. The CPE identifier cpe:2.3:a:linux:linux indicates this affects the Linux kernel product itself across all architectures and configurations.

RemediationAI

The primary remediation is to upgrade the Linux kernel to a patched version: for kernel 6.5 users, upgrade to 6.5.13 or later; for 6.12 users, upgrade to 6.12.77 or later; for 6.18 users, upgrade to 6.18.17 or later; for 6.19 users, upgrade to 6.19.7 or later; for 7.0-rc users, upgrade to 7.0-rc3 or later. The specific upstream fixes are available at the git.kernel.org stable commit references provided (15fb6d627484ee39ed73e202ef4720e1fa5c898e, 5a501379a010690ae9ae88bef62a1bae1aca32e6, baef52d80093bd686e70b3cb7e0512a40ae76705, c3320153769f05fd7fe9d840cb555dd3080ae424). Most Linux distributions have already backported this fix to their kernel packages; verify your distribution's security advisory and apply the available kernel update through your package manager (apt, yum, zypper, etc.). Until kernel patching is possible, system administrators can mitigate local DoS risk by restricting ioctl access to trusted applications through AppArmor or SELinux policies targeting the blkdev ioctl interface (BLKPRGET, BLKPRSET commands), though this may impact legitimate NVMe PR functionality.

Vendor StatusVendor

Debian

linux
Release Status Fixed Version Urgency
bullseye not-affected - -
bullseye (security) fixed 5.10.251-1 -
bookworm not-affected - -
bookworm (security) fixed 6.1.164-1 -
trixie vulnerable 6.12.73-1 -
trixie (security) vulnerable 6.12.74-2 -
forky vulnerable 6.19.6-2 -
sid fixed 6.19.8-1 -
(unstable) fixed 6.19.8-1 -

SUSE

Severity: High
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Fixed
SUSE Linux Enterprise Desktop 15 SP7 Fixed
SUSE Linux Enterprise High Availability Extension 15 SP7 Fixed
SUSE Linux Enterprise High Availability Extension 15 SP7 Fixed
SUSE Linux Enterprise High Performance Computing 15 SP7 Fixed

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EUVD-2026-12805 vulnerability details – vuln.today

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