CVE-2022-49546

MEDIUM EPSS 17.7%
Published Feb 26, 20251y ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Feb 26, 2025 1y ago
Last Modified Jun 17, 2026 1w ago

Description

In the Linux kernel, the following vulnerability has been resolved: x86/kexec: fix memory leak of elf header buffer This is reported by kmemleak detector: unreferenced object 0xffffc900002a9000 (size 4096): comm "kexec", pid 14950, jiffies 4295110793 (age 373.951s) hex dump (first 32 bytes): 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 .ELF............ 04 00 3e 00 01 00 00 00 00 00 00 00 00 00 00 00 ..>............. backtrace: [<0000000016a8ef9f>] __vmalloc_node_range+0x101/0x170 [<000000002b66b6c0>] __vmalloc_node+0xb4/0x160 [<00000000ad40107d>] crash_prepare_elf64_headers+0x8e/0xcd0 [<0000000019afff23>] crash_load_segments+0x260/0x470 [<0000000019ebe95c>] bzImage64_load+0x814/0xad0 [<0000000093e16b05>] arch_kexec_kernel_image_load+0x1be/0x2a0 [<000000009ef2fc88>] kimage_file_alloc_init+0x2ec/0x5a0 [<0000000038f5a97a>] __do_sys_kexec_file_load+0x28d/0x530 [<0000000087c19992>] do_syscall_64+0x3b/0x90 [<0000000066e063a4>] entry_SYSCALL_64_after_hwframe+0x44/0xae In crash_prepare_elf64_headers(), a buffer is allocated via vmalloc() to store elf headers. While it's not freed back to system correctly when kdump kernel is reloaded or unloaded. Then memory leak is caused. Fix it by introducing x86 specific function arch_kimage_file_post_load_cleanup(), and freeing the buffer there. And also remove the incorrect elf header buffer freeing code. Before calling arch specific kexec_file loading function, the image instance has been initialized. So 'image->elf_headers' must be NULL. It doesn't make sense to free the elf header buffer in the place. Three different people have reported three bugs about the memory leak on x86_64 inside Redhat.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
17.7% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-401

Affected Products 3

VendorProductVersionRange
linuxlinux_kernel* <5.15.46
linuxlinux_kernel*≥5.16  –  <5.17.14
linuxlinux_kernel*≥5.18  –  <5.18.3

References 6

  • git.kernel.org https://git.kernel.org/stable/c/115ee42a4c2f26ba2b4ace2668a3f004621f6833
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/23cf39dccf7653650701a6f39b119e9116a27f1a
  • git.kernel.org https://git.kernel.org/stable/c/8765a423a87d74ef24ea02b43b2728fe4039f248
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b3e34a47f98974d0844444c5121aaff123004e57
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f675e3a9189d84a9324ab45b0cb19906c2bc8fcb
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/115ee42a4c2f26ba2b4ace2668a3f004621f6833
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/8765a423a87d74ef24ea02b43b2728fe4039f248
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b3e34a47f98974d0844444c5121aaff123004e57
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f675e3a9189d84a9324ab45b0cb19906c2bc8fcb
    Patch