Linux Kernel up to 6.12.63/6.18.2/6.19-rc1 num_syncs allocation of resources

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.63/6.18.2/6.19-rc1. It has been declared as critical. This vulnerability affects unknown code. Such manipulation of the argument num_syncs leads to allocation of resources. This vulnerability is referenced as CVE-2025-68802. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.63/6.18.2/6.19-rc1. It has been rated as critical. Affected by this issue is some unknown processing. The manipulation of the argument num_syncs with an unknown input leads to a allocation of resources vulnerability. Using CWE to declare the problem leads to CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: drm/xe: Limit num_syncs to prevent oversized allocations The exec and vm_bind ioctl allow userspace to specify an arbitrary num_syncs value. Without bounds checking, a very large num_syncs can force an excessively large allocation, leading to kernel warnings from the page allocator as below. Introduce DRM_XE_MAX_SYNCS (set to 1024) and reject any request exceeding this limit. " ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1217 at mm/page_alloc.c:5124 __alloc_frozen_pages_noprof+0x2f8/0x2180 mm/page_alloc.c:5124 ... Call Trace: <TASK> alloc_pages_mpol+0xe4/0x330 mm/mempolicy.c:2416 ___kmalloc_large_node+0xd8/0x110 mm/slub.c:4317 __kmalloc_large_node_noprof+0x18/0xe0 mm/slub.c:4348 __do_kmalloc_node mm/slub.c:4364 [inline] __kmalloc_noprof+0x3d4/0x4b0 mm/slub.c:4388 kmalloc_noprof include/linux/slab.h:909 [inline] kmalloc_array_noprof include/linux/slab.h:948 [inline] xe_exec_ioctl+0xa47/0x1e70 drivers/gpu/drm/xe/xe_exec.c:158 drm_ioctl_kernel+0x1f1/0x3e0 drivers/gpu/drm/drm_ioctl.c:797 drm_ioctl+0x5e7/0xc50 drivers/gpu/drm/drm_ioctl.c:894 xe_drm_ioctl+0x10b/0x170 drivers/gpu/drm/xe/xe_device.c:224 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xbb/0x380 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f ... " v2: Add "Reported-by" and Cc stable kernels. v3: Change XE_MAX_SYNCS from 64 to 1024. (Matt & Ashutosh) v4: s/XE_MAX_SYNCS/DRM_XE_MAX_SYNCS/ (Matt) v5: Do the check at the top of the exec func. (Matt) (cherry picked from commit b07bac9bd708ec468cd1b8a5fe70ae2ac9b0a11c)

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2025-68802 since 12/24/2025. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 307005 (Ubuntu 25.10 : Linux kernel vulnerabilities (USN-8177-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.64, 6.18.3 or 6.19-rc2 eliminates this vulnerability. Applying the patch e281d1fd6903a081ef023c341145ae92258e38d2/1d200017f55f829b9e376093bd31dfbec92081de/8e461304009135270e9ccf2d7e2dfe29daec9b60 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (307005) and CERT Bund (WID-SEC-2026-0086). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.12.58
• 6.12.59
• 6.12.60
• 6.12.61
• 6.12.62
• 6.12.63
• 6.18.0
• 6.18.1
• 6.18.2
• 6.19-rc1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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Entryinfo

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