CVE-2022-49546
Estado: ModificadaMedia (5.5)—
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:
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.
Leer descripción completaMostrar menos
Three different people have reported three bugs about the memory leak on x86_64 inside Redhat.
Detalles técnicos trazas, registros y código del informe original
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+0x44/0xaeCVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 5.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.28%
- Percentil entre todas las CVEs puntuadas: 18
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-401
Referencias
- https://git.kernel.org/stable/c/115ee42a4c2f26ba2b4ace2668a3f004621f6833
- https://git.kernel.org/stable/c/23cf39dccf7653650701a6f39b119e9116a27f1a
- https://git.kernel.org/stable/c/8765a423a87d74ef24ea02b43b2728fe4039f248
- https://git.kernel.org/stable/c/b3e34a47f98974d0844444c5121aaff123004e57
- https://git.kernel.org/stable/c/f675e3a9189d84a9324ab45b0cb19906c2bc8fcb
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
JSON original (NVD)
Mostrar
{
"id": "CVE-2022-49546",
"cveTags": [],
"metrics": {
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{
"type": "Primary",
"source": "nvd@nist.gov",
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"version": "3.1",
"baseScore": 5.5,
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "NONE"
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"description": [
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"descriptions": [
{
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/kexec: fix memory leak of elf header buffer\n\nThis is reported by kmemleak detector:\n\nunreferenced object 0xffffc900002a9000 (size 4096):\n comm \"kexec\", pid 14950, jiffies 4295110793 (age 373.951s)\n hex dump (first 32 bytes):\n 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 .ELF............\n 04 00 3e 00 01 00 00 00 00 00 00 00 00 00 00 00 ..>.............\n backtrace:\n [<0000000016a8ef9f>] __vmalloc_node_range+0x101/0x170\n [<000000002b66b6c0>] __vmalloc_node+0xb4/0x160\n [<00000000ad40107d>] crash_prepare_elf64_headers+0x8e/0xcd0\n [<0000000019afff23>] crash_load_segments+0x260/0x470\n [<0000000019ebe95c>] bzImage64_load+0x814/0xad0\n [<0000000093e16b05>] arch_kexec_kernel_image_load+0x1be/0x2a0\n [<000000009ef2fc88>] kimage_file_alloc_init+0x2ec/0x5a0\n [<0000000038f5a97a>] __do_sys_kexec_file_load+0x28d/0x530\n [<0000000087c19992>] do_syscall_64+0x3b/0x90\n [<0000000066e063a4>] entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nIn crash_prepare_elf64_headers(), a buffer is allocated via vmalloc() to\nstore elf headers. While it's not freed back to system correctly when\nkdump kernel is reloaded or unloaded. Then memory leak is caused. Fix it\nby introducing x86 specific function arch_kimage_file_post_load_cleanup(),\nand freeing the buffer there.\n\nAnd also remove the incorrect elf header buffer freeing code. Before\ncalling arch specific kexec_file loading function, the image instance has\nbeen initialized. So 'image->elf_headers' must be NULL. It doesn't make\nsense to free the elf header buffer in the place.\n\nThree different people have reported three bugs about the memory leak on\nx86_64 inside Redhat."
},
{
"lang": "es",
"value": "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 ..>............. 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(), 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->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."
}
],
"lastModified": "2026-06-17T05:18:24.450",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
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"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}