---
id: CVE-2026-98509
title: 'drm/virtio: fix memory leak of fence event on execbuffer failure'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  drm/virtio: fix memory leak of fence event on execbuffer failure

  virtio_gpu_execbuffer_ioctl() reserves a DRM event with
  drm_event_reserve_init() when VIRTGPU_EXECBUF_…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= cd7f5ca33585918febe5e2f6dc090a21cfa775b0 <
    43bfe2b60c149bf6effda25f245a00509061fa15
  - >-
    Linux >= cd7f5ca33585918febe5e2f6dc090a21cfa775b0 <
    4e333e2336138f4659b1d7a0371c499f80428612
  - >-
    Linux >= cd7f5ca33585918febe5e2f6dc090a21cfa775b0 <
    8fa78900fd24247277c03dc7b8a2864cb12d4340
  - >-
    Linux >= cd7f5ca33585918febe5e2f6dc090a21cfa775b0 <
    ae583668f16d41fcc1b54f45848c1b6ac1d6669a
  - >-
    Linux >= cd7f5ca33585918febe5e2f6dc090a21cfa775b0 <
    b74aad23d99b279bb34d135795f39a6d8ecdc075
  - Linux 5.16
published: '2026-10-18'
updated: '2026-10-18'
sourceUpdated: '2026-10-18T15:17:19.352Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98509'
references:
  - url: 'https://git.kernel.org/stable/c/43bfe2b60c149bf6effda25f245a00509061fa15'
  - url: 'https://git.kernel.org/stable/c/4e333e2336138f4659b1d7a0371c499f80428612'
  - url: 'https://git.kernel.org/stable/c/8fa78900fd24247277c03dc7b8a2864cb12d4340'
  - url: 'https://git.kernel.org/stable/c/ae583668f16d41fcc1b54f45848c1b6ac1d6669a'
  - url: 'https://git.kernel.org/stable/c/b74aad23d99b279bb34d135795f39a6d8ecdc075'
tags:
  - cve.org
ingestedAt: '2026-10-18T15:45:12.286Z'
---

## Overview

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

drm/virtio: fix memory leak of fence event on execbuffer failure

virtio_gpu_execbuffer_ioctl() reserves a DRM event with
drm_event_reserve_init() when VIRTGPU_EXECBUF_RING_IDX selects a ring that
userspace has enabled polling for. virtio_gpu_init_submit() does this
before the BO handles, the command buffer, the syncobj arrays and the
in-fence are processed, so every later error path runs with the event
already pending, including plain argument validation failures such as an
invalid bo_handle or an in-syncobj that carries no fence.

On those paths, virtio_gpu_cleanup_submit() drops the out-fence without
cancelling the event. The fence is freed without ever having been emitted,
taking the only driver-side pointer to the event with it. Closing the DRM
file does not help. drm_events_release() unlinks pending events but
deliberately leaves the freeing to the driver's later drm_send_event(),
which never runs for an orphaned event, so the allocation is leaked
permanently.

Found when fuzzing the virtio driver with Syzkaller:

	BUG: memory leak
	unreferenced object 0xffff88802c176e80 (size 96):
	comm "syz.1.367", pid 10561, jiffies 4294960122
	hex dump (first 32 bytes):
		00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
		c8 6e 17 2c 80 88 ff ff 00 00 00 00 00 00 00 00  .n.,............
	backtrace (crc e1973c6b):
		kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
		slab_post_alloc_hook mm/slub.c:4597 [inline]
		slab_alloc_node mm/slub.c:4917 [inline]
		__kmalloc_cache_noprof+0x49d/0x6f0 mm/slub.c:5485
		_kmalloc_noprof include/linux/slab.h:988 [inline]
		_kzalloc_noprof include/linux/slab.h:1309 [inline]
		virtio_gpu_fence_event_create drivers/gpu/drm/virtio/virtgpu_submit.c:282 [inline]
		virtio_gpu_init_submit drivers/gpu/drm/virtio/virtgpu_submit.c:398 [inline]
		virtio_gpu_execbuffer_ioctl+0xbbf/0x1aa0 drivers/gpu/drm/virtio/virtgpu_submit.c:505
		drm_ioctl_kernel+0x1f4/0x3e0 drivers/gpu/drm/drm_ioctl.c:817
		drm_ioctl+0x5f4/0xc70 drivers/gpu/drm/drm_ioctl.c:914
		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+0x18e/0x210 fs/ioctl.c:583
		do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
		do_syscall_64+0x116/0x800 arch/x86/entry/syscall_64.c:94
		entry_SYSCALL_64_after_hwframe+0x77/0x7f

Fix by cancelling and freeing the DRM event on the execbuffer error path
before dropping the fence. Clear the fence's event pointer after
cancellation so it does not retain a dangling pointer.

## Affected

- `Linux >= cd7f5ca33585918febe5e2f6dc090a21cfa775b0 < 43bfe2b60c149bf6effda25f245a00509061fa15`
- `Linux >= cd7f5ca33585918febe5e2f6dc090a21cfa775b0 < 4e333e2336138f4659b1d7a0371c499f80428612`
- `Linux >= cd7f5ca33585918febe5e2f6dc090a21cfa775b0 < 8fa78900fd24247277c03dc7b8a2864cb12d4340`
- `Linux >= cd7f5ca33585918febe5e2f6dc090a21cfa775b0 < ae583668f16d41fcc1b54f45848c1b6ac1d6669a`
- `Linux >= cd7f5ca33585918febe5e2f6dc090a21cfa775b0 < b74aad23d99b279bb34d135795f39a6d8ecdc075`
- `Linux 5.16`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.