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TI-2026-75636 Aliases CVE-2026-98508GHSA-4gjh-xj79-p5g5

NULL pointer dereference in Linux kernel virtio GPU fence handling

Priority LOW 22Published · Updated

Key facts

Attack vector
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Privileges required
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User interaction
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Attack complexity
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Impact type
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Confidentiality · integrity · availability
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Fix status
Partial Red Hat: 4 without a fix

No CVSS vector from any source. Fix status from CNA and Red Hat.

Summary

The Linux kernel drm/virtio driver never checks whether fence allocation succeeded. When allocation fails under memory pressure, virtio_gpu_init_submit() passes a NULL fence to virtio_gpu_fence_event_create(), which dereferences it, causing a NULL pointer dereference. The fault was found by fuzzing the virtio driver with Syzkaller and crashes the kernel.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Description from the CNA

In the Linux kernel, the following vulnerability has been resolved: drm/virtio: fix NULL pointer dereference on fence allocation failure virtio_gpu_fence_alloc() can fail due to memory pressure and return NULL, but its caller like virtio_gpu_init_submit() never checks it. Later, virtio_gpu_init_submit() passes the NULL fence to virtio_gpu_fence_event_create(), which unconditionally dereferences it. Found when fuzzing the virtio driver with Syzkaller: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097] CPU: 1 UID: 0 PID: 9991 Comm: syz.0.121 Not tainted 7.2.0 #4 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 RIP: 0010:virtio_gpu_fence_event_create drivers/gpu/drm/virtio/virtgpu_submit.c:295 [inline] RIP: 0010:virtio_gpu_init_submit drivers/gpu/drm/virtio/virtgpu_submit.c:398 [inline] RIP: 0010:virtio_gpu_execbuffer_ioctl+0xc78/0x1aa0 drivers/gpu/drm/virtio/virtgpu_submit.c:505 Code: 85 ed 0f 85 21 09 00 00 e8 05 5a c9 fb 48 8b 44 24 10 48 8d b8 90 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 9a 0d 00 00 48 8b 44 24 10 4c 89 b0 90 00 00 00 RSP: 0018:ffffc900039dfad0 EFLAGS: 00010216 RAX: dffffc0000000000 RBX: ffffc900039dfdd8 RCX: ffffffff85f6fd3d RDX: 0000000000000012 RSI: ffffffff85f6fd4b RDI: 0000000000000090 RBP: 0000000000000000 R0virtio_gpu_virgl_process_cmd: ctrl 0x102, error 0x1203 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880132c4000 R13: 0000000000000000 R14: ffff888073b6c700 R15: 000000000000003b FS: 00007fab480b96c0(0000) GS:ffff8880eb6e9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007effbf5e55a8 CR3: 0000000048d19000 CR4: 0000000000350ef0 Call Trace: <TASK> 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 RIP: 0033:0x7fab471a82bd Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fab480b9018 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fab47435fa0 RCX: 00007fab471a82bd RDX: 00002000000000c0 RSI: 00000000c0406442 RDI: 0000000000000003 RBP: 00007fab480b9080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fab47436038 R14: 00007fab47435fa0 R15: 00007ffe85ab0740 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:virtio_gpu_fence_event_create drivers/gpu/drm/virtio/virtgpu_submit.c:295 [inline] RIP: 0010:virtio_gpu_init_submit drivers/gpu/drm/virtio/virtgpu_submit.c:398 [inline] RIP: 0010:virtio_gpu_execbuffer_ioctl+0xc78/0x1aa0 drivers/gpu/drm/virtio/virtgpu_submit.c:505 Code: 85 ed 0f 85 21 09 00 00 e8 05 5a c9 fb 48 8b 44 24 10 48 8d b8 90 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 9a 0d 00 00 48 8b 44 24 10 4c 89 b0 90 00 00 00 RSP: 0018:ffffc900039dfad0 EFLAGS: 00010216 RAX: dffffc0000000000 RBX: ffffc900039dfdd8 RCX: ffffffff85f6fd3d RDX: 0000000000000012 RSI: ffffffff85f6fd4b RDI: 0000000000000090 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880132c4000 R13: 0000000000000000 R14: ffff888073b6c700 R15: 000000000000003b FS: 00007fab480b96c0(0000) GS:ffff888098ae9000(0000) knlGS:00000000 ---truncated---

Why it matters now

EPSS 0.002 9th percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.2, 6.6, 6.6.158 +4Red Hat: 4 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.1.54 to before 6.2; 6.5.4 to before 6.66.2, 6.6Patch availableCNA
LinuxLinux6.6 and later6.6.158, 6.12.112, 6.18.55, 7.2.9, 7.3Patch availableCNA
  • Linux VendorLinux Affected 6.1.54 to before 6.2; 6.5.4 to before 6.6 Fixed in 6.2, 6.6 Patch available CNA
  • Linux VendorLinux Affected 6.6 and later Fixed in 6.6.158, 6.12.112, 6.18.55, 7.2.9, 7.3 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

Upgrade the Linux kernel to 6.2, 6.6, 6.6.158, 6.12.112, 6.18.55, 7.2.9 or 7.3, or a later release in the same branch. Red Hat Enterprise Linux 9, Red Hat Enterprise Linux 10, Red Hat OpenShift Container Platform 4 and Red Hat OpenShift Container Platform 5 are affected without a fix, and Red Hat lists its plan for them as none available.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

  • Fix · CNA Linux (Linux) Fixed in 6.2, 6.6
  • Fix · CNA Linux (Linux) Fixed in 6.6.158, 6.12.112, 6.18.55, 7.2.9, 7.3

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Not affected: 5 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9
  • Red Hat OpenShift Container Platform 4

Timeline

  1. 2026-10-18 Threatist record created from CVE-2026-98508
  2. 2026-10-18 Alias added: GHSA-4gjh-xj79-p5g5
  3. 2026-10-19 Fix available: Linux/[email protected] · CNA
  4. 2026-10-20 Affected versions changed · Red Hat
  5. 2026-10-20 CVSS score added · Red Hat
  6. 2026-10-30 Affected versions changed · Red Hat

References

Other 5

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences