CVE-2022-49546

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2022-49546
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.

5.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/115ee42a4c2f26ba2b4ace2668a3f004621f6833 Patch
https://git.kernel.org/stable/c/23cf39dccf7653650701a6f39b119e9116a27f1a
https://git.kernel.org/stable/c/8765a423a87d74ef24ea02b43b2728fe4039f248 Patch
https://git.kernel.org/stable/c/b3e34a47f98974d0844444c5121aaff123004e57 Patch
https://git.kernel.org/stable/c/f675e3a9189d84a9324ab45b0cb19906c2bc8fcb Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
History

10 Apr 2025, 13:15

Type Values Removed Values Added
CWE CWE-401
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
First Time Linux linux Kernel
Linux
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: x86/kexec: se corrige la pérdida de memoria del búfer de encabezado elf Esto lo informa el detector kmemleak: objeto sin referencia 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 ..&gt;............. backtrace: [&lt;0000000016a8ef9f&gt;] __vmalloc_node_range+0x101/0x170 [&lt;000000002b66b6c0&gt;] __vmalloc_node+0xb4/0x160 [&lt;00000000ad40107d&gt;] crash_prepare_elf64_headers+0x8e/0xcd0 [&lt;0000000019afff23&gt;] crash_load_segments+0x260/0x470 [&lt;0000000019ebe95c&gt;] bzImage64_load+0x814/0xad0 [&lt;0000000093e16b05&gt;] arch_kexec_kernel_image_load+0x1be/0x2a0 [&lt;000000009ef2fc88&gt;] kimage_file_alloc_init+0x2ec/0x5a0 [&lt;0000000038f5a97a&gt;] __do_sys_kexec_file_load+0x28d/0x530 [&lt;0000000087c19992&gt;] do_syscall_64+0x3b/0x90 [&lt;0000000066e063a4&gt;] entry_SYSCALL_64_after_hwframe+0x44/0xae In crash_prepare_elf64_headers(), se asigna un búfer a través de vmalloc() para almacenar encabezados elf. Sin embargo, no se libera correctamente al sistema cuando se vuelve a cargar o descargar el kernel kdump. Entonces se produce una pérdida de memoria. Arréglelo introduciendo la función específica x86 arch_kimage_file_post_load_cleanup() y liberando el búfer allí. Y también elimine el código incorrecto de liberación del búfer del encabezado elf. Antes de llamar a la función de carga kexec_file específica de arch, se ha inicializado la instancia de la imagen. Por lo tanto, 'image-&gt;elf_headers' debe ser NULL. No tiene sentido liberar el búfer del encabezado elf en ese lugar. Tres personas diferentes han informado tres errores sobre la pérdida de memoria en x86_64 dentro de Redhat.
References
  • () https://git.kernel.org/stable/c/23cf39dccf7653650701a6f39b119e9116a27f1a -
References () https://git.kernel.org/stable/c/115ee42a4c2f26ba2b4ace2668a3f004621f6833 - () https://git.kernel.org/stable/c/115ee42a4c2f26ba2b4ace2668a3f004621f6833 - Patch
References () https://git.kernel.org/stable/c/8765a423a87d74ef24ea02b43b2728fe4039f248 - () https://git.kernel.org/stable/c/8765a423a87d74ef24ea02b43b2728fe4039f248 - Patch
References () https://git.kernel.org/stable/c/b3e34a47f98974d0844444c5121aaff123004e57 - () https://git.kernel.org/stable/c/b3e34a47f98974d0844444c5121aaff123004e57 - Patch
References () https://git.kernel.org/stable/c/f675e3a9189d84a9324ab45b0cb19906c2bc8fcb - () https://git.kernel.org/stable/c/f675e3a9189d84a9324ab45b0cb19906c2bc8fcb - Patch

26 Feb 2025, 07:01

Type Values Removed Values Added
New CVE
Information

Published : 2025-02-26 07:01

Updated : 2025-04-10 13:15

NVD link : CVE-2022-49546

Mitre link : CVE-2022-49546

CVE.ORG link : CVE-2022-49546

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-401

Missing Release of Memory after Effective Lifetime