CVE-2026-98515 (GCVE-0-2026-98515)
Vulnerability from cvelistv5
Published
2026-10-18 15:17
Modified
2026-10-24 14:09
Summary
In the Linux kernel, the following vulnerability has been resolved: drm/nouveau: fix double-free in nvif_vmm_dtor On failure, nouveau_cli_init() calls nouveau_cli_fini() to tear the client down. Then, nouveau_drm_open() also enters into its cleanup path and calls nouveau_cli_fini() AGAIN. nouveau_cli_fini() calls nouveau_vmm_fini(): void nouveau_vmm_fini(struct nouveau_vmm *vmm) { nouveau_svmm_fini(&vmm->svmm); nvif_vmm_dtor(&vmm->vmm); vmm->cli = NULL; } Inside nvif_vmm_dtor(), vmm->page is freed unconditionally: void nvif_vmm_dtor(struct nvif_vmm *vmm) { kfree(vmm->page); nvif_object_dtor(&vmm->object); } vmm->page is never cleared after being freed, so the second call of nvif_vmm_dtor() will cause a double-free. Found by fuzzing the nouveau driver with a modified Syzkaller: BUG: KASAN: double-free in nvif_vmm_dtor+0x31/0x50 drivers/gpu/drm/nouveau/nvif/vmm.c:194 Free of addr ffff888010fcdc30 by task syz.0.173/2567 CPU: 1 UID: 0 PID: 2567 Comm: syz.0.173 Not tainted 7.2.0 #24 PREEMPT(lazy) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 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_invalid_free+0xaa/0xd0 mm/kasan/report.c:557 check_slab_allocation+0xe4/0x110 mm/kasan/common.c:235 kasan_slab_pre_free include/linux/kasan.h:199 [inline] slab_free_hook mm/slub.c:2622 [inline] slab_free mm/slub.c:6377 [inline] kfree+0x192/0x590 mm/slub.c:6692 nvif_vmm_dtor+0x31/0x50 drivers/gpu/drm/nouveau/nvif/vmm.c:194 nouveau_vmm_fini+0x16/0x50 drivers/gpu/drm/nouveau/nouveau_vmm.c:127 nouveau_cli_fini+0x10e/0x210 drivers/gpu/drm/nouveau/nouveau_drm.c:225 nouveau_drm_open+0x24e/0x740 drivers/gpu/drm/nouveau/nouveau_drm.c:1255 drm_file_alloc+0x5f2/0xad0 drivers/gpu/drm/drm_file.c:176 drm_open_helper+0x1d7/0x4a0 drivers/gpu/drm/drm_file.c:335 drm_open+0x190/0x3d0 drivers/gpu/drm/drm_file.c:388 drm_stub_open+0x1f2/0x460 drivers/gpu/drm/drm_drv.c:1211 chrdev_open+0x21c/0x660 fs/char_dev.c:411 do_dentry_open+0x59d/0x12b0 fs/open.c:947 vfs_open+0x82/0x390 fs/open.c:1052 do_open fs/namei.c:4700 [inline] path_openat+0x2345/0x3420 fs/namei.c:4863 do_file_open+0x207/0x460 fs/namei.c:4892 do_sys_openat2+0xd1/0x1d0 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x144/0x200 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x690 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc6d687594d 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:00007fc6d5295008 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fc6d6b06180 RCX: 00007fc6d687594d RDX: 0000000000022501 RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007fc6d691c303 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc6d6b06218 R14: 00007fc6d6b06180 R15: 00007ffd9451d760 </TASK> Allocated by task 2567 on cpu 1 at 163.593900s: 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] nvif_vmm_ctor+0x3c0/0x7e0 drivers/gpu/drm/nouveau/nvif/vmm.c:237 nouveau_vmm_init+0x40/0x90 drivers/gpu/drm/nouveau/nouveau_vmm.c:134 nouveau_cli_init+0x7b9/0 ---truncated---
Impacted products
Vendor Product Version
Linux Linux Version: 20d8a88e557aae5264e793f4626c45cd644c7144
Version: 20d8a88e557aae5264e793f4626c45cd644c7144
Version: 20d8a88e557aae5264e793f4626c45cd644c7144
Version: 20d8a88e557aae5264e793f4626c45cd644c7144
Version: 20d8a88e557aae5264e793f4626c45cd644c7144
Version: 20d8a88e557aae5264e793f4626c45cd644c7144
Version: 20d8a88e557aae5264e793f4626c45cd644c7144
Version: 20d8a88e557aae5264e793f4626c45cd644c7144
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{
  "containers": {
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            "drivers/gpu/drm/nouveau/nouveau_drm.c",
            "drivers/gpu/drm/nouveau/nvif/vmm.c"
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          "programFiles": [
            "drivers/gpu/drm/nouveau/nouveau_drm.c",
            "drivers/gpu/drm/nouveau/nvif/vmm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
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              "versionType": "original_commit_for_fix"
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      "cpeApplicability": [
        {
          "nodes": [
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              "negate": false,
              "operator": "OR"
            }
          ]
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/nouveau: fix double-free in nvif_vmm_dtor\n\nOn failure, nouveau_cli_init() calls nouveau_cli_fini() to tear\nthe client down. Then, nouveau_drm_open() also enters into its\ncleanup path and calls nouveau_cli_fini() AGAIN. nouveau_cli_fini()\ncalls nouveau_vmm_fini():\n\n\tvoid\n\tnouveau_vmm_fini(struct nouveau_vmm *vmm)\n\t{\n\t\tnouveau_svmm_fini(\u0026vmm-\u003esvmm);\n\t\tnvif_vmm_dtor(\u0026vmm-\u003evmm);\n\t\tvmm-\u003ecli = NULL;\n\t}\n\nInside nvif_vmm_dtor(), vmm-\u003epage is freed unconditionally:\n\n\tvoid\n\tnvif_vmm_dtor(struct nvif_vmm *vmm)\n\t{\n\t\tkfree(vmm-\u003epage);\n\t\tnvif_object_dtor(\u0026vmm-\u003eobject);\n\t}\n\nvmm-\u003epage is never cleared after being freed, so the second call of\nnvif_vmm_dtor() will cause a double-free.\n\nFound by fuzzing the nouveau driver with a modified Syzkaller:\n\n\tBUG: KASAN: double-free in nvif_vmm_dtor+0x31/0x50 drivers/gpu/drm/nouveau/nvif/vmm.c:194\n\tFree of addr ffff888010fcdc30 by task syz.0.173/2567\n\n\tCPU: 1 UID: 0 PID: 2567 Comm: syz.0.173 Not tainted 7.2.0 #24 PREEMPT(lazy)\n\tHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n\tCall Trace:\n\t\u003cTASK\u003e\n\t__dump_stack lib/dump_stack.c:94 [inline]\n\tdump_stack_lvl+0x95/0xe0 lib/dump_stack.c:120\n\tprint_address_description mm/kasan/report.c:378 [inline]\n\tprint_report+0xcb/0x5a0 mm/kasan/report.c:482\n\tkasan_report_invalid_free+0xaa/0xd0 mm/kasan/report.c:557\n\tcheck_slab_allocation+0xe4/0x110 mm/kasan/common.c:235\n\tkasan_slab_pre_free include/linux/kasan.h:199 [inline]\n\tslab_free_hook mm/slub.c:2622 [inline]\n\tslab_free mm/slub.c:6377 [inline]\n\tkfree+0x192/0x590 mm/slub.c:6692\n\tnvif_vmm_dtor+0x31/0x50 drivers/gpu/drm/nouveau/nvif/vmm.c:194\n\tnouveau_vmm_fini+0x16/0x50 drivers/gpu/drm/nouveau/nouveau_vmm.c:127\n\tnouveau_cli_fini+0x10e/0x210 drivers/gpu/drm/nouveau/nouveau_drm.c:225\n\tnouveau_drm_open+0x24e/0x740 drivers/gpu/drm/nouveau/nouveau_drm.c:1255\n\tdrm_file_alloc+0x5f2/0xad0 drivers/gpu/drm/drm_file.c:176\n\tdrm_open_helper+0x1d7/0x4a0 drivers/gpu/drm/drm_file.c:335\n\tdrm_open+0x190/0x3d0 drivers/gpu/drm/drm_file.c:388\n\tdrm_stub_open+0x1f2/0x460 drivers/gpu/drm/drm_drv.c:1211\n\tchrdev_open+0x21c/0x660 fs/char_dev.c:411\n\tdo_dentry_open+0x59d/0x12b0 fs/open.c:947\n\tvfs_open+0x82/0x390 fs/open.c:1052\n\tdo_open fs/namei.c:4700 [inline]\n\tpath_openat+0x2345/0x3420 fs/namei.c:4863\n\tdo_file_open+0x207/0x460 fs/namei.c:4892\n\tdo_sys_openat2+0xd1/0x1d0 fs/open.c:1368\n\tdo_sys_open fs/open.c:1374 [inline]\n\t__do_sys_openat fs/open.c:1390 [inline]\n\t__se_sys_openat fs/open.c:1385 [inline]\n\t__x64_sys_openat+0x144/0x200 fs/open.c:1385\n\tdo_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n\tdo_syscall_64+0x115/0x690 arch/x86/entry/syscall_64.c:94\n\tentry_SYSCALL_64_after_hwframe+0x77/0x7f\n\tRIP: 0033:0x7fc6d687594d\n\tCode: 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 \u003c48\u003e 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48\n\tRSP: 002b:00007fc6d5295008 EFLAGS: 00000246 ORIG_RAX: 0000000000000101\n\tRAX: ffffffffffffffda RBX: 00007fc6d6b06180 RCX: 00007fc6d687594d\n\tRDX: 0000000000022501 RSI: 0000200000000000 RDI: ffffffffffffff9c\n\tRBP: 00007fc6d691c303 R08: 0000000000000000 R09: 0000000000000000\n\tR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\n\tR13: 00007fc6d6b06218 R14: 00007fc6d6b06180 R15: 00007ffd9451d760\n\t\u003c/TASK\u003e\n\n\tAllocated by task 2567 on cpu 1 at 163.593900s:\n\tkasan_save_stack+0x24/0x50 mm/kasan/common.c:57\n\tkasan_save_track+0x17/0x60 mm/kasan/common.c:78\n\tpoison_kmalloc_redzone mm/kasan/common.c:398 [inline]\n\t__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415\n\tkasan_kmalloc include/linux/kasan.h:263 [inline]\n\t__do_kmalloc_node mm/slub.c:5334 [inline]\n\t__kmalloc_noprof+0x304/0x7c0 mm/slub.c:5359\n\t_kmalloc_noprof include/linux/slab.h:992 [inline]\n\tnvif_vmm_ctor+0x3c0/0x7e0 drivers/gpu/drm/nouveau/nvif/vmm.c:237\n\tnouveau_vmm_init+0x40/0x90 drivers/gpu/drm/nouveau/nouveau_vmm.c:134\n\tnouveau_cli_init+0x7b9/0\n---truncated---"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - An attacker reaches patched nvif_vmm_dtor() by locally opening a Nouveau DRM node: openat() \u2192 drm_open() \u2192 drm_file_alloc() \u2192 nouveau_drm_open() \u2192 nouveau_cli_init()/nouveau_cli_fini() \u2192 nouveau_vmm_fini(). No network or radio data enters this path.\nAC:L - Each successful open creates per-client VMM state and a dedicated scheduler workqueue; repeated opens and memory pressure can make the later nvif_mclass() or nouveau_sched_create() allocation fail after vmm-\u003epage exists. The two unwinders then deterministically call nvif_vmm_dtor() twice, with no race.\nPR:L - Nouveau advertises DRIVER_RENDER, and drm_file_alloc() invokes nouveau_drm_open() for /dev/dri/renderD* without a capable(), DRM-master, or authentication check. A local unprivileged user with ordinary render-node access suffices.\nUI:N - The attacker performs the render-node opens and resource-pressure sequence themselves; no other user must mount media, open a file, or take any action.\nS:U - The duplicate free corrupts the host kernel\u0027s own slab allocator and may yield local kernel privilege escalation, but it does not cross a VM, IOMMU, or other distinct security authority.\nC:H - nvif_vmm_dtor() frees the same kmalloc-backed vmm-\u003epage object twice, allowing its slab slot to be returned twice and reclaimed as overlapping allocations. Heap grooming can expose contents written through the aliased kernel object, enabling kernel-memory disclosure.\nI:H - The duplicate kfree(vmm-\u003epage) corrupts the SLUB freelist; later allocations can alias the same slot, so writes through one allocation corrupt the other and can be developed into arbitrary-write or control-flow-hijack primitives.\nA:H - The reported path produces an immediate KASAN double-free in nvif_vmm_dtor(); without KASAN it can trigger SLUB\u0027s hardened double-free BUG or corrupt the freelist and cause a subsequent kernel oops or panic."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-24T14:09:13.699Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/023e7a01f8fb27799f0987b5bcda325d73a2904c"
        },
        {
          "url": "https://git.kernel.org/stable/c/375901ac0f286e81be00a4126e57d488cb401884"
        },
        {
          "url": "https://git.kernel.org/stable/c/bf542ecd4f60d4689818d194e7ca74772fe0f8b5"
        },
        {
          "url": "https://git.kernel.org/stable/c/f09f4a536935b15539f2de9fe775a2641202be90"
        },
        {
          "url": "https://git.kernel.org/stable/c/279e5ac137370e274a09dd552547ae6bddd0d4d5"
        },
        {
          "url": "https://git.kernel.org/stable/c/109a8d2d5b7d2719ebe09df3f9241023900b3846"
        },
        {
          "url": "https://git.kernel.org/stable/c/872a5473c02a26c955be44d52b7ab2f8ea70a2cf"
        },
        {
          "url": "https://git.kernel.org/stable/c/97077ac87afe9e91ec074ef0be64454e7ccbf344"
        }
      ],
      "title": "drm/nouveau: fix double-free in nvif_vmm_dtor",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98515",
    "datePublished": "2026-10-18T15:17:31.953Z",
    "dateReserved": "2026-09-25T10:25:14.354Z",
    "dateUpdated": "2026-10-24T14:09:13.699Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.


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