---
id: "CVE-2026-98517"
kind: "vulnerability"
aliases: ["CVE-2026-98517"]
title: "Linux kernel nouveau driver: use-after-free when buffer sits in system memory"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "kernel", "linux", "nouveau", "nvidia-gpu"]
not_affected_if: ["no-nouveau-driver", "proprietary-nvidia-driver"]
published_at: "2026-10-18T16:17:03+00:00"
first_seen_at: "2026-10-23T21:57:15+00:00"
updated_at: "2026-10-25T05:25:17+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98517", "first_seen_at": "2026-10-23T21:57:15+00:00"}]
---

# Linux kernel nouveau driver: use-after-free when buffer sits in system memory

The nouveau GPU driver in the Linux kernel reads a memory-resource structure as if it were a larger type when a buffer object is in system memory, causing a KASAN-reported use-after-free in nouveau_uvmm_sm. The sources do not state the attacker-reachable impact beyond the crash report.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `uname -r` and check whether the kernel includes the nouveau driver (`lsmod | grep nouveau`)
- Check whether the running kernel build predates the upstream fix for drm/nouveau/uvmm, using the distribution's changelog
- unknown whether the sources list a specific affected version range

## Fix

- Update the Linux kernel to a release that includes the upstream drm/nouveau/uvmm fix (version not stated in the sources: unknown)
- Reboot after installing the patched kernel

## Timeline

- 2026-10-23T21:57:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98517

## From the sources

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

drm/nouveau/uvmm: fix UAF in nouveau_uvmm_sm when BO is in TTM_PL_SYSTEM

nouveau_uvmm_sm() calls op_map(), which passes bo->resource through
nouveau_mem() to nouveau_uvma_map(). nouveau_uvmm_vmm_map() then reads
mem->mem.type.

But this is only valid when bo->resource is backed by struct nouveau_mem,
as is the case for VRAM and TT resources. If the BO is left in
TTM_PL_SYSTEM, bo->resource is only a struct ttm_resource. Treating it
as struct nouveau_mem makes the mem->mem.type read past the end of the
resource, causing a KASAN: slab-use-after-free Read in nouveau_uvmm_sm
report:

BUG: KASAN: slab-use-after-free in nouveau_uvmm_vmm_map drivers/gpu/drm/nouveau/nouveau_uvmm.c:152 [inline]
BUG: KASAN: slab-use-after-free in nouveau_uvma_map drivers/gpu/drm/nouveau/nouveau_uvmm.c:199 [inline]
BUG: KASAN: slab-use-after-free in op_map drivers/gpu/drm/nouveau/nouveau_uvmm.c:849 [inline]
BUG: KASAN: slab-use-after-free in nouveau_uvmm_sm.constprop.0+0x6ab/0x900 drivers/gpu/drm/nouveau/nouveau_uvmm.c:903
Read of size 1 at addr ffff888127d3e3a0 by task kworker/0:1/11

CPU: 0 UID: 0 PID: 11 Comm: kworker/0:1 Not tainted 7.2.0 #5 PREEMPT(lazy)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: nouveau_sched_wq_2224 drm_sched_run_job_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x95/0xe0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xcb/0x5a0 mm/kasan/report.c:482
 kasan_report+0xca/0x100 mm/kasan/report.c:595
 nouveau_uvmm_vmm_map drivers/gpu/drm/nouveau/nouveau_uvmm.c:152 [inline]
 nouveau_uvma_map drivers/gpu/drm/nouveau/nouveau_uvmm.c:199 [inline]
 op_map drivers/gpu/drm/nouveau/nouveau_uvmm.c:849 [inline]
 nouveau_uvmm_sm.constprop.0+0x6ab/0x900 drivers/gpu/drm/nouveau/nouveau_uvmm.c:903
 nouveau_uvmm_sm_unmap drivers/gpu/drm/nouveau/nouveau_uvmm.c:932 [inline]
 nouveau_uvmm_bind_job_run+0xd6/0x250 drivers/gpu/drm/nouveau/nouveau_uvmm.c:1532
 nouveau_job_run drivers/gpu/drm/nouveau/nouveau_sched.c:350 [inline]
 nouveau_sched_run_job+0x62/0xd0 drivers/gpu/drm/nouveau/nouveau_sched.c:364
 drm_sched_run_job_work+0x356/0xa10 drivers/gpu/drm/scheduler/sched_main.c:1061
 process_one_work+0x8a5/0x1900 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5dd/0xd80 kernel/workqueue.c:3486
 kthread+0x31d/0x420 kernel/kthread.c:436
 ret_from_fork+0x662/0x940 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 2224 on cpu 0 at 66.550027s:
 kasan_save_stack+0x24/0x50 mm/kasan/common.c:57
 kasan_save_track+0x17/0x60 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5334 [inline]
 __kmalloc_noprof+0x304/0x7c0 mm/slub.c:5359
 _kmalloc_noprof include/linux/slab.h:992 [inline]
 dma_resv_list_alloc+0x27/0x90 drivers/dma-buf/dma-resv.c:106
 dma_resv_reserve_fences+0x60e/0xa30 drivers/dma-buf/dma-resv.c:205
 ttm_bo_alloc_resource+0x12c/0xbd0 drivers/gpu/drm/ttm/ttm_bo.c:721
 ttm_bo_validate+0x1bc/0x4a0 drivers/gpu/drm/ttm/ttm_bo.c:856
 ttm_bo_init_reserved+0x2c3/0x570 drivers/gpu/drm/ttm/ttm_bo.c:970
 nouveau_bo_init+0x159/0x2c0 drivers/gpu/drm/nouveau/nouveau_bo.c:359
 nouveau_gem_new+0x234/0x5f0 drivers/gpu/drm/nouveau/nouveau_gem.c:272
 nouveau_gem_ioctl_new+0x1eb/0x420 drivers/gpu/drm/nouveau/nouveau_gem.c:352
 drm_ioctl_kernel+0x192/0x350 drivers/gpu/drm/drm_ioctl.c:817
 drm_ioctl+0x4f8/0xb40 drivers/gpu/drm/drm_ioctl.c:914
 nouveau_drm_ioctl+0xea/0x2c0 drivers/gpu/drm/nouveau/nouveau_drm.c:1338
 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+0x180/0x1d0 fs/ioctl.c:583
 do_syscall_x64 ar
---truncated---

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_
