{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbootconfig: use memblock_free_late to free xbc memory to buddy\n\nOn the time to free xbc memory in xbc_exit(), memblock may has handed\nover memory to buddy allocator. So it doesn't make sense to free memory\nback to memblock. memblock_free() called by xbc_exit() even causes UAF bugs\non architectures with CONFIG_ARCH_KEEP_MEMBLOCK disabled like x86.\nFollowing KASAN logs shows this case.\n\nThis patch fixes the xbc memory free problem by calling memblock_free()\nin early xbc init error rewind path and calling memblock_free_late() in\nxbc exit path to free memory to buddy allocator.\n\n[    9.410890] ==================================================================\n[    9.418962] BUG: KASAN: use-after-free in memblock_isolate_range+0x12d/0x260\n[    9.426850] Read of size 8 at addr ffff88845dd30000 by task swapper/0/1\n\n[    9.435901] CPU: 9 PID: 1 Comm: swapper/0 Tainted: G     U             6.9.0-rc3-00208-g586b5dfb51b9 #5\n[    9.446403] Hardware name: Intel Corporation RPLP LP5 (CPU:RaptorLake)/RPLP LP5 (ID:13), BIOS IRPPN02.01.01.00.00.19.015.D-00000000 Dec 28 2023\n[    9.460789] Call Trace:\n[    9.463518]  <TASK>\n[    9.465859]  dump_stack_lvl+0x53/0x70\n[    9.469949]  print_report+0xce/0x610\n[    9.473944]  ? __virt_addr_valid+0xf5/0x1b0\n[    9.478619]  ? memblock_isolate_range+0x12d/0x260\n[    9.483877]  kasan_report+0xc6/0x100\n[    9.487870]  ? memblock_isolate_range+0x12d/0x260\n[    9.493125]  memblock_isolate_range+0x12d/0x260\n[    9.498187]  memblock_phys_free+0xb4/0x160\n[    9.502762]  ? __pfx_memblock_phys_free+0x10/0x10\n[    9.508021]  ? mutex_unlock+0x7e/0xd0\n[    9.512111]  ? __pfx_mutex_unlock+0x10/0x10\n[    9.516786]  ? kernel_init_freeable+0x2d4/0x430\n[    9.521850]  ? __pfx_kernel_init+0x10/0x10\n[    9.526426]  xbc_exit+0x17/0x70\n[    9.529935]  kernel_init+0x38/0x1e0\n[    9.533829]  ? _raw_spin_unlock_irq+0xd/0x30\n[    9.538601]  ret_from_fork+0x2c/0x50\n[    9.542596]  ? __pfx_kernel_init+0x10/0x10\n[    9.547170]  ret_from_fork_asm+0x1a/0x30\n[    9.551552]  </TASK>\n\n[    9.555649] The buggy address belongs to the physical page:\n[    9.561875] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x45dd30\n[    9.570821] flags: 0x200000000000000(node=0|zone=2)\n[    9.576271] page_type: 0xffffffff()\n[    9.580167] raw: 0200000000000000 ffffea0011774c48 ffffea0012ba1848 0000000000000000\n[    9.588823] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000\n[    9.597476] page dumped because: kasan: bad access detected\n\n[    9.605362] Memory state around the buggy address:\n[    9.610714]  ffff88845dd2ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[    9.618786]  ffff88845dd2ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[    9.626857] >ffff88845dd30000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n[    9.634930]                    ^\n[    9.638534]  ffff88845dd30080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n[    9.646605]  ffff88845dd30100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n[    9.654675] =================================================================="
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "include/linux/bootconfig.h",
                  "lib/bootconfig.c"
               ],
               "versions": [
                  {
                     "version": "40caa127f3c7",
                     "lessThan": "1e7feb31a18c",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "40caa127f3c7",
                     "lessThan": "e46d3be714ad",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "40caa127f3c7",
                     "lessThan": "5a7dfb8fcd3f",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "40caa127f3c7",
                     "lessThan": "89f9a1e876b5",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "include/linux/bootconfig.h",
                  "lib/bootconfig.c"
               ],
               "versions": [
                  {
                     "version": "5.15",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "5.15",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.1.88",
                     "lessThanOrEqual": "6.1.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.6.29",
                     "lessThanOrEqual": "6.6.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.8.8",
                     "lessThanOrEqual": "6.8.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.9",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/1e7feb31a18c197d63a5e606025ed63c762f8918"
            },
            {
               "url": "https://git.kernel.org/stable/c/e46d3be714ad9652480c6db129ab8125e2d20ab7"
            },
            {
               "url": "https://git.kernel.org/stable/c/5a7dfb8fcd3f29fc93161100179b27f24f3d5f35"
            },
            {
               "url": "https://git.kernel.org/stable/c/89f9a1e876b5a7ad884918c03a46831af202c8a0"
            }
         ],
         "title": "bootconfig: use memblock_free_late to free xbc memory to buddy",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-26983",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}