CVE-2026-64582: Software Security Vulnerability Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9mqw-m8jv-5hmw",
  "modified" : "2026-10-19T21:35:41Z",
  "published" : "2026-08-05T12:31:33Z",
  "aliases" : [ "CVE-2026-64582" ],
  "details" : "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's kref is still at 1:\n\n   list_del_init(&ip->pending_mmaps);\n   spin_unlock_bh(&rxe->pending_lock);   /* ref == 1, no lock held */\n   ret = remap_vmalloc_range(vma, ip->obj, 0);  /* walks PTEs */\n   [...]\n   rxe_vma_open(vma);                    /* kref_get, ref → 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(&q->ip->ref, rxe_mmap_release)   /* ref 1→0 */\n    vfree(ip->obj)   /* 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 -> vm_insert_page(NULL) → 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'd 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 <80> 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   <TASK>\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---",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-64582"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/3371f2036e0f970166bbb624e25bba46d32fa18e"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/3525987a392536f31a484833af258971af63b24c"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/35744ab3d03c5fca8c1752f53fc8fc674e14c561"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/665fb7d22a700c66a78db0cf88c6e6a649aba9d0"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/aef5ea8578f97f2701039600846a8bcf5f21e863"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/b810352d0916796dabe633cdb9adee9863ab4911"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/e038d42cc09ca1da9d3568ce8ae062b2bfb3bc0e"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/e59a6aa89e0fcd1d0707832eb4654fd9ae7d31e6"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-416" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-05T12:18:57Z"
  }
}