CVE-2026-64582 (GCVE-0-2026-64582)
Vulnerability from cvelistv5
Published
2026-08-05 11:25
Modified
2026-08-19 16:29
Summary
In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix a use-after-free problem in rxe_mmap rxe_mmap() removes a rxe_mmap_info struct from the pending_mmaps list and releases pending_lock while the struct's kref is still at 1: list_del_init(&ip->pending_mmaps); spin_unlock_bh(&rxe->pending_lock); /* ref == 1, no lock held */ ret = remap_vmalloc_range(vma, ip->obj, 0); /* walks PTEs */ [...] rxe_vma_open(vma); /* kref_get, ref → 2 */ remap_vmalloc_range_partial() walks PTEs without any lock. A concurrent DESTROY_CQ ioctl on another CPU calls: kref_put(&q->ip->ref, rxe_mmap_release) /* ref 1→0 */ vfree(ip->obj) /* clears vmalloc PTEs mid-walk */ kfree(ip) /* frees rxe_mmap_info */ This yields: 1. Kernel crash, vmalloc_to_page() returns NULL when vfree wins the per-PTE race -> vm_insert_page(NULL) → GPF in validate_page_before_insert 2. Page UAF, vmalloc_to_page() reads a stale PTE before vfree clears it. User VMA holds a PTE to a free'd page which might eventually get reallocated later by vmalloc which allows the attacker to get a clean page-level UAF. It is worth noting that even though a page-level UAF is possible given the strong primitive, it is statistically very difficult to achieve given the very short time window (after the last insert_page and before the kref_get). The call trace are as below: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 UID: 1000 PID: 413 Comm: poc Not tainted 7.0.0-rc5-dirty #28 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:validate_page_before_insert+0x32/0x300 Code: e5 41 57 41 56 49 89 fe 41 55 41 54 53 48 89 f3 e8 93 b5 a3 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 7b 02 00 00 4c 8b 63 08 31 ff 4d 89 e5 41 83 e5 RSP: 0018:ffff88811b15f2f0 EFLAGS: 00000202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000008 RBP: ffff88811b15f318 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881181eee00 R13: 0000000000000000 R14: ffff8881181eee00 R15: ffff8881181eee20 FS: 00007b1e000f76c0(0000) GS:ffff8884268e0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007b1e00a24ac0 CR3: 0000000116eb3000 CR4: 00000000000006f0 Call Trace: <TASK> insert_page+0x8f/0x190 ? __pfx_insert_page+0x10/0x10 ? kasan_save_alloc_info+0x38/0x60 vm_insert_page+0x2e7/0x400 remap_vmalloc_range_partial+0x212/0x3e0 remap_vmalloc_range+0x6e/0xb0 ? __kasan_check_write+0x14/0x30 rxe_mmap+0x2e9/0x5d0 ib_uverbs_mmap+0x1ad/0x2c0 __mmap_region+0x12c2/0x2ad0 ? __pfx___mmap_region+0x10/0x10 ? __sanitizer_cov_trace_switch+0x58/0xb0 ? mas_prev_slot+0x360/0x39c0 ? __sanitizer_cov_trace_switch+0x58/0xb0 ? mas_next_slot+0x1e5b/0x2f40 ? __sanitizer_cov_trace_cmp8+0x18/0x30 ? unmapped_area_topdown+0x4dd/0x610 ? kfree+0x1b1/0x440 ? free_cpumask_var+0x16/0x30 ? __kasan_slab_free+0x7d/0xa0 ? __sanitizer_cov_trace_cmp8+0x18/0x30 mmap_region+0x2e6/0x3c0 do_mmap+0xa3e/0x12a0 ? __pfx_do_mmap+0x10/0x10 ? __kasan_check_write+0x14/0x30 ? down_write_killable+0xba/0x160 ? __pfx_down_write_killable+0x10/0x10 ? __sanitizer_cov_trace_cmp4+0x16/0x30 vm_mmap_pgoff+0x2d4/0x4a0 ? __pfx_vm_mmap_pgoff+0x10/0x10 ? fget+0x1bf/0x270 ksys_mmap_pgoff+0x40c/0x690 ? __sanitizer_cov_trace_const_cmp4+0x16/0x30 ? __pfx_ksys_mmap_pgoff+0x10/0x10 ? __kasan_check_write+0x14/0x30 ? _raw_spin_trylock+0xbb/0x130 ? __pfx__raw_spin_trylock+0x10/0x10 __x64_sys_mmap+0x135/0x1e0 x64_sys_c ---truncated---
Impacted products
Vendor Product Version
Linux Linux Version: 8700e3e7c4857d28ebaa824509934556da0b3e76
Version: 8700e3e7c4857d28ebaa824509934556da0b3e76
Version: 8700e3e7c4857d28ebaa824509934556da0b3e76
Version: 8700e3e7c4857d28ebaa824509934556da0b3e76
Version: 8700e3e7c4857d28ebaa824509934556da0b3e76
Version: 8700e3e7c4857d28ebaa824509934556da0b3e76
Version: 8700e3e7c4857d28ebaa824509934556da0b3e76
Version: 8700e3e7c4857d28ebaa824509934556da0b3e76
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{
  "containers": {
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          "product": "Linux",
          "programFiles": [
            "drivers/infiniband/sw/rxe/rxe_mmap.c"
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          ],
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          "vendor": "Linux",
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              "version": "0",
              "versionType": "semver"
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              "status": "unaffected",
              "version": "5.10.265",
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              "status": "unaffected",
              "version": "5.15.216",
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              "status": "unaffected",
              "version": "6.1.183",
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              "status": "unaffected",
              "version": "6.6.145",
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              "status": "unaffected",
              "version": "6.12.97",
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            },
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              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
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              "version": "7.1.5",
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              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
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        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
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              "cpeMatch": [
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                  "versionEndExcluding": "7.2",
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                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Fix a use-after-free problem in rxe_mmap\n\nrxe_mmap() removes a rxe_mmap_info struct from the pending_mmaps list\nand releases pending_lock while the struct\u0027s kref is still at 1:\n\n   list_del_init(\u0026ip-\u003epending_mmaps);\n   spin_unlock_bh(\u0026rxe-\u003epending_lock);   /* ref == 1, no lock held */\n   ret = remap_vmalloc_range(vma, ip-\u003eobj, 0);  /* walks PTEs */\n   [...]\n   rxe_vma_open(vma);                    /* kref_get, ref \u2192 2 */\n   remap_vmalloc_range_partial() walks PTEs without any lock.\n\nA concurrent DESTROY_CQ ioctl on another CPU calls:\n\n    kref_put(\u0026q-\u003eip-\u003eref, rxe_mmap_release)   /* ref 1\u21920 */\n    vfree(ip-\u003eobj)   /* clears vmalloc PTEs mid-walk */\n    kfree(ip)        /* frees rxe_mmap_info */\n\nThis yields:\n\n   1. Kernel crash, vmalloc_to_page() returns NULL when vfree wins the\n   per-PTE race -\u003e vm_insert_page(NULL) \u2192 GPF in validate_page_before_insert\n\n   2. Page UAF, vmalloc_to_page() reads a stale PTE before vfree clears\n   it. User VMA holds a PTE to a free\u0027d page which might eventually get\n   reallocated later by vmalloc which allows the attacker to get a clean\n   page-level UAF.\n\n   It is worth noting that even though a page-level UAF is possible given\n   the strong primitive, it is statistically very difficult to achieve\n   given the very short time window (after the last insert_page and before\n   the kref_get).\n\nThe call trace are as below:\n\n  Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI\n  KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]\n  CPU: 0 UID: 1000 PID: 413 Comm: poc Not tainted 7.0.0-rc5-dirty #28 PREEMPT(lazy)\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\n  RIP: 0010:validate_page_before_insert+0x32/0x300\n  Code: e5 41 57 41 56 49 89 fe 41 55 41 54 53 48 89 f3 e8 93 b5 a3 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 \u003c80\u003e 3c 02 00 0f 85 7b 02 00 00 4c 8b 63 08 31 ff 4d 89 e5 41 83 e5\n  RSP: 0018:ffff88811b15f2f0 EFLAGS: 00000202\n  RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000\n  RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000008\n  RBP: ffff88811b15f318 R08: 0000000000000000 R09: 0000000000000000\n  R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881181eee00\n  R13: 0000000000000000 R14: ffff8881181eee00 R15: ffff8881181eee20\n  FS:  00007b1e000f76c0(0000) GS:ffff8884268e0000(0000) knlGS:0000000000000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  CR2: 00007b1e00a24ac0 CR3: 0000000116eb3000 CR4: 00000000000006f0\n  Call Trace:\n   \u003cTASK\u003e\n   insert_page+0x8f/0x190\n   ? __pfx_insert_page+0x10/0x10\n   ? kasan_save_alloc_info+0x38/0x60\n   vm_insert_page+0x2e7/0x400\n   remap_vmalloc_range_partial+0x212/0x3e0\n   remap_vmalloc_range+0x6e/0xb0\n   ? __kasan_check_write+0x14/0x30\n   rxe_mmap+0x2e9/0x5d0\n   ib_uverbs_mmap+0x1ad/0x2c0\n   __mmap_region+0x12c2/0x2ad0\n   ? __pfx___mmap_region+0x10/0x10\n   ? __sanitizer_cov_trace_switch+0x58/0xb0\n   ? mas_prev_slot+0x360/0x39c0\n   ? __sanitizer_cov_trace_switch+0x58/0xb0\n   ? mas_next_slot+0x1e5b/0x2f40\n   ? __sanitizer_cov_trace_cmp8+0x18/0x30\n   ? unmapped_area_topdown+0x4dd/0x610\n   ? kfree+0x1b1/0x440\n   ? free_cpumask_var+0x16/0x30\n   ? __kasan_slab_free+0x7d/0xa0\n   ? __sanitizer_cov_trace_cmp8+0x18/0x30\n   mmap_region+0x2e6/0x3c0\n   do_mmap+0xa3e/0x12a0\n   ? __pfx_do_mmap+0x10/0x10\n   ? __kasan_check_write+0x14/0x30\n   ? down_write_killable+0xba/0x160\n   ? __pfx_down_write_killable+0x10/0x10\n   ? __sanitizer_cov_trace_cmp4+0x16/0x30\n   vm_mmap_pgoff+0x2d4/0x4a0\n   ? __pfx_vm_mmap_pgoff+0x10/0x10\n   ? fget+0x1bf/0x270\n   ksys_mmap_pgoff+0x40c/0x690\n   ? __sanitizer_cov_trace_const_cmp4+0x16/0x30\n   ? __pfx_ksys_mmap_pgoff+0x10/0x10\n   ? __kasan_check_write+0x14/0x30\n   ? _raw_spin_trylock+0xbb/0x130\n   ? __pfx__raw_spin_trylock+0x10/0x10\n   __x64_sys_mmap+0x135/0x1e0\n   x64_sys_c\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 - Triggered via local mmap on /dev/infiniband/uverbsN (ib_uverbs_mmap\u2192rxe_mmap) racing DESTROY_CQ/QP/SRQ ioctls; not reachable from RoCE/UDP packet processing.\nAC:L - Attacker controls both sides\u2014mmap of the pending CQ/QP/SRQ queue buffer and concurrent destroy that kref_puts to rxe_mmap_release\u2014and can retry unboundedly; PoC shows reliable crash.\nPR:L - uverbs_devnode() publishes /dev/infiniband/uverbs* as 0666 with no capability checks on create/mmap/destroy; once Soft-RoCE exists (admin setup), any unprivileged user (PoC UID 1000) can exploit.\nUI:N - Attacker opens uverbs, creates a CQ/QP/SRQ, then races mmap with destroy from its own threads; no victim action required.\nS:U - UAF corrupts kernel heap/vmalloc within the host kernel authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Race frees rxe_mmap_info and vfree\u0027s the queue while remap_vmalloc_range still walks it; stale PTEs can leave a user VMA mapped to reallocated pages, enabling page-level UAF reads.\nI:H - Same page-level UAF / freed-object control yields write primitives via remapped freed pages and heap reuse, sufficient for control-flow hijacking per UAF guidance.\nA:H - Concurrent vfree during PTE walk returns NULL to vm_insert_page, causing the documented GPF/oops in validate_page_before_insert; crash is reliably repeatable."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-19T16:29:09.006Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b810352d0916796dabe633cdb9adee9863ab4911"
        },
        {
          "url": "https://git.kernel.org/stable/c/aef5ea8578f97f2701039600846a8bcf5f21e863"
        },
        {
          "url": "https://git.kernel.org/stable/c/3371f2036e0f970166bbb624e25bba46d32fa18e"
        },
        {
          "url": "https://git.kernel.org/stable/c/665fb7d22a700c66a78db0cf88c6e6a649aba9d0"
        },
        {
          "url": "https://git.kernel.org/stable/c/e038d42cc09ca1da9d3568ce8ae062b2bfb3bc0e"
        },
        {
          "url": "https://git.kernel.org/stable/c/e59a6aa89e0fcd1d0707832eb4654fd9ae7d31e6"
        },
        {
          "url": "https://git.kernel.org/stable/c/3525987a392536f31a484833af258971af63b24c"
        },
        {
          "url": "https://git.kernel.org/stable/c/35744ab3d03c5fca8c1752f53fc8fc674e14c561"
        }
      ],
      "title": "RDMA/rxe: Fix a use-after-free problem in rxe_mmap",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64582",
    "datePublished": "2026-08-05T11:25:29.082Z",
    "dateReserved": "2026-07-19T15:36:31.798Z",
    "dateUpdated": "2026-08-19T16:29:09.006Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
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