CVE-2025-40225
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-12-04

Last updated on: 2025-12-04

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: drm/panthor: Fix kernel panic on partial unmap of a GPU VA region This commit address a kernel panic issue that can happen if Userspace tries to partially unmap a GPU virtual region (aka drm_gpuva). The VM_BIND interface allows partial unmapping of a BO. Panthor driver pre-allocates memory for the new drm_gpuva structures that would be needed for the map/unmap operation, done using drm_gpuvm layer. It expected that only one new drm_gpuva would be needed on umap but a partial unmap can require 2 new drm_gpuva and that's why it ended up doing a NULL pointer dereference causing a kernel panic. Following dump was seen when partial unmap was exercised. Unable to handle kernel NULL pointer dereference at virtual address 0000000000000078 Mem abort info: ESR = 0x0000000096000046 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000046, ISS2 = 0x00000000 CM = 0, WnR = 1, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=000000088a863000 [000000000000078] pgd=080000088a842003, p4d=080000088a842003, pud=0800000884bf5003, pmd=0000000000000000 Internal error: Oops: 0000000096000046 [#1] PREEMPT SMP <snip> pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : panthor_gpuva_sm_step_remap+0xe4/0x330 [panthor] lr : panthor_gpuva_sm_step_remap+0x6c/0x330 [panthor] sp : ffff800085d43970 x29: ffff800085d43970 x28: ffff00080363e440 x27: ffff0008090c6000 x26: 0000000000000030 x25: ffff800085d439f8 x24: ffff00080d402000 x23: ffff800085d43b60 x22: ffff800085d439e0 x21: ffff00080abdb180 x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000010 x17: 6e656c202c303030 x16: 3666666666646466 x15: 393d61766f69202c x14: 312d3d7361203a70 x13: 303030323d6e656c x12: ffff80008324bf58 x11: 0000000000000003 x10: 0000000000000002 x9 : ffff8000801a6a9c x8 : ffff00080360b300 x7 : 0000000000000000 x6 : 000000088aa35fc7 x5 : fff1000080000000 x4 : ffff8000842ddd30 x3 : 0000000000000001 x2 : 0000000100000000 x1 : 0000000000000001 x0 : 0000000000000078 Call trace: panthor_gpuva_sm_step_remap+0xe4/0x330 [panthor] op_remap_cb.isra.22+0x50/0x80 __drm_gpuvm_sm_unmap+0x10c/0x1c8 drm_gpuvm_sm_unmap+0x40/0x60 panthor_vm_exec_op+0xb4/0x3d0 [panthor] panthor_vm_bind_exec_sync_op+0x154/0x278 [panthor] panthor_ioctl_vm_bind+0x160/0x4a0 [panthor] drm_ioctl_kernel+0xbc/0x138 drm_ioctl+0x240/0x500 __arm64_sys_ioctl+0xb0/0xf8 invoke_syscall+0x4c/0x110 el0_svc_common.constprop.1+0x98/0xf8 do_el0_svc+0x24/0x38 el0_svc+0x40/0xf8 el0t_64_sync_handler+0xa0/0xc8 el0t_64_sync+0x174/0x178
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Meta Information
Published
2025-12-04
Last Modified
2025-12-04
Generated
2026-05-07
AI Q&A
2025-12-04
EPSS Evaluated
2026-05-05
NVD
CVE-2025-40225
EUVD
EUVD-2025-201234
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux kernel *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a kernel panic issue in the Linux kernel's Panthor driver related to the handling of partial unmapping of GPU virtual address (VA) regions. When userspace attempts to partially unmap a GPU VA region using the VM_BIND interface, the driver incorrectly assumes only one new drm_gpuva structure is needed. However, partial unmapping can require two new drm_gpuva structures. This mismatch leads to a NULL pointer dereference, causing the kernel to panic and crash.


How can this vulnerability impact me? :

This vulnerability can cause the Linux kernel to panic and crash when a partial unmap operation on a GPU virtual address region is performed. This results in system instability and potential downtime, affecting any applications or services relying on GPU operations and potentially leading to data loss or interruption of service.


How can this vulnerability be detected on my network or system? Can you suggest some commands?

This vulnerability manifests as a kernel panic caused by a NULL pointer dereference in the panthor driver when a partial unmap of a GPU virtual address region is attempted. Detection involves monitoring system logs for kernel panic messages related to the panthor driver, specifically looking for error messages like 'Unable to handle kernel NULL pointer dereference at virtual address 0000000000000078' and call traces involving 'panthor_gpuva_sm_step_remap'. You can check the kernel logs using commands such as 'dmesg | grep panthor' or 'journalctl -k | grep panthor' to identify related kernel panic events.


What immediate steps should I take to mitigate this vulnerability?

Immediate mitigation involves updating the Linux kernel to a version where this vulnerability is fixed, as the issue is resolved by a commit addressing the kernel panic in the panthor driver. Until an update is applied, avoid performing partial unmap operations on GPU virtual address regions that use the panthor driver to prevent triggering the kernel panic.


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