CVE-2022-49341

In the Linux kernel, the following vulnerability has been resolved: bpf, arm64: Clear prog->jited_len along prog->jited syzbot reported an illegal copy_to_user() attempt from bpf_prog_get_info_by_fd() [1] There was no repro yet on this bug, but I think that commit 0aef499f3172 ("mm/usercopy: Detect vmalloc overruns") is exposing a prior bug in bpf arm64. bpf_prog_get_info_by_fd() looks at prog->jited_len to determine if the JIT image can be copied out to user space. My theory is that syzbot managed to get a prog where prog->jited_len has been set to 43, while prog->bpf_func has ben cleared. It is not clear why copy_to_user(uinsns, NULL, ulen) is triggering this particular warning. I thought find_vma_area(NULL) would not find a vm_struct. As we do not hold vmap_area_lock spinlock, it might be possible that the found vm_struct was garbage. [1] usercopy: Kernel memory exposure attempt detected from vmalloc (offset 792633534417210172, size 43)! kernel BUG at mm/usercopy.c:101! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 25002 Comm: syz-executor.1 Not tainted 5.18.0-syzkaller-10139-g8291eaafed36 #0 Hardware name: linux,dummy-virt (DT) pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : usercopy_abort+0x90/0x94 mm/usercopy.c:101 lr : usercopy_abort+0x90/0x94 mm/usercopy.c:89 sp : ffff80000b773a20 x29: ffff80000b773a30 x28: faff80000b745000 x27: ffff80000b773b48 x26: 0000000000000000 x25: 000000000000002b x24: 0000000000000000 x23: 00000000000000e0 x22: ffff80000b75db67 x21: 0000000000000001 x20: 000000000000002b x19: ffff80000b75db3c x18: 00000000fffffffd x17: 2820636f6c6c616d x16: 76206d6f72662064 x15: 6574636574656420 x14: 74706d6574746120 x13: 2129333420657a69 x12: 73202c3237313031 x11: 3237313434333533 x10: 3336323937207465 x9 : 657275736f707865 x8 : ffff80000a30c550 x7 : ffff80000b773830 x6 : ffff80000b773830 x5 : 0000000000000000 x4 : ffff00007fbbaa10 x3 : 0000000000000000 x2 : 0000000000000000 x1 : f7ff000028fc0000 x0 : 0000000000000064 Call trace: usercopy_abort+0x90/0x94 mm/usercopy.c:89 check_heap_object mm/usercopy.c:186 [inline] __check_object_size mm/usercopy.c:252 [inline] __check_object_size+0x198/0x36c mm/usercopy.c:214 check_object_size include/linux/thread_info.h:199 [inline] check_copy_size include/linux/thread_info.h:235 [inline] copy_to_user include/linux/uaccess.h:159 [inline] bpf_prog_get_info_by_fd.isra.0+0xf14/0xfdc kernel/bpf/syscall.c:3993 bpf_obj_get_info_by_fd+0x12c/0x510 kernel/bpf/syscall.c:4253 __sys_bpf+0x900/0x2150 kernel/bpf/syscall.c:4956 __do_sys_bpf kernel/bpf/syscall.c:5021 [inline] __se_sys_bpf kernel/bpf/syscall.c:5019 [inline] __arm64_sys_bpf+0x28/0x40 kernel/bpf/syscall.c:5019 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x48/0x114 arch/arm64/kernel/syscall.c:52 el0_svc_common.constprop.0+0x44/0xec arch/arm64/kernel/syscall.c:142 do_el0_svc+0xa0/0xc0 arch/arm64/kernel/syscall.c:206 el0_svc+0x44/0xb0 arch/arm64/kernel/entry-common.c:624 el0t_64_sync_handler+0x1ac/0x1b0 arch/arm64/kernel/entry-common.c:642 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:581 Code: aa0003e3 d00038c0 91248000 97fff65f (d4210000)
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:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.19:rc1:*:*:*:*:*:*

History

21 Oct 2025, 12:18

Type Values Removed Values Added
CWE NVD-CWE-noinfo
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: bpf, arm64: Borrar prog->jited_len junto con prog->jited syzbot informó un intento ilegal de copy_to_user() desde bpf_prog_get_info_by_fd() [1] Todavía no hubo reproducción de este error, pero creo que el commit 0aef499f3172 ("mm/usercopy: Detectar desbordamientos de vmalloc") está exponiendo un error anterior en bpf arm64. bpf_prog_get_info_by_fd() analiza prog->jited_len para determinar si la imagen JIT se puede copiar al espacio de usuario. Mi teoría es que syzbot logró obtener un programa donde prog->jited_len se ha establecido en 43, mientras que prog->bpf_func se ha borrado. No está claro por qué copy_to_user(uinsns, NULL, ulen) está activando esta advertencia en particular. Pensé que find_vma_area(NULL) no encontraría un vm_struct. Como no tenemos el bloqueo de giro vmap_area_lock, es posible que el vm_struct encontrado fuera basura. [1] usercopy: ¡Se detectó un intento de exposición de memoria del kernel desde vmalloc (desplazamiento 792633534417210172, tamaño 43)! ¡ERROR del kernel en mm/usercopy.c:101! Error interno: Oops - BUG: 0 [#1] PREEMPT Módulos SMP vinculados en: CPU: 0 PID: 25002 Comm: syz-executor.1 No contaminado 5.18.0-syzkaller-10139-g8291eaafed36 #0 Nombre del hardware: linux,dummy-virt (DT) pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : usercopy_abort+0x90/0x94 mm/usercopy.c:101 lr : usercopy_abort+0x90/0x94 mm/usercopy.c:89 sp : ffff80000b773a20 x29: ffff80000b773a30 x28: faff80000b745000 x27: ffff80000b773b48 x26: 0000000000000000 x25: 000000000000002b x24: 00000000000000000 x23: 00000000000000e0 x22: ffff80000b75db67 x21: 0000000000000001 x20: 000000000000002b x19: ffff80000b75db3c x18: 00000000fffffffd x17: 2820636f6c6c616d x16: 76206d6f72662064 x15: 6574636574656420 x14: 74706d6574746120 x13: 2129333420657a69 x12: 73202c3237313031 x11: 3237313434333533 x10: 3336323937207465 x9: 657275736f707865 x8: ffff80000a30c550 x7: ffff80000b773830 x6: ffff80000b773830 x5: 0000000000000000 x4 : ffff00007fbbaa10 x3 : 0000000000000000 x2 : 0000000000000000 x1 : f7ff000028fc0000 x0 : 00000000000000064 Rastreo de llamadas: usercopy_abort+0x90/0x94 mm/usercopy.c:89 check_heap_object mm/usercopy.c:186 [en línea] __check_object_size mm/usercopy.c:252 [en línea] __check_object_size+0x198/0x36c mm/usercopy.c:214 check_object_size include/linux/thread_info.h:199 [en línea] check_copy_size include/linux/thread_info.h:235 [en línea] copia_al_usuario include/linux/uaccess.h:159 [en línea] bpf_prog_get_info_by_fd.isra.0+0xf14/0xfdc kernel/bpf/syscall.c:3993 bpf_obj_get_info_by_fd+0x12c/0x510 kernel/bpf/syscall.c:4253 __sys_bpf+0x900/0x2150 kernel/bpf/syscall.c:4956 __do_sys_bpf kernel/bpf/syscall.c:5021 [en línea] __se_sys_bpf kernel/bpf/syscall.c:5019 [en línea] __arm64_sys_bpf+0x28/0x40 kernel/bpf/syscall.c:5019 __invoke_syscall arch/arm64/kernel/syscall.c:38 [en línea] invocar_syscall+0x48/0x114 arch/arm64/kernel/syscall.c:52 el0_svc_common.constprop.0+0x44/0xec arch/arm64/kernel/syscall.c:142 do_el0_svc+0xa0/0xc0 arch/arm64/kernel/syscall.c:206 el0_svc+0x44/0xb0 arch/arm64/kernel/entry-common.c:624 el0t_64_sync_handler+0x1ac/0x1b0 arch/arm64/kernel/entry-common.c:642 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:581 Código: aa0003e3 d00038c0 91248000 97fff65f (d4210000)
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.19:rc1:*:*:*:*:*:*
First Time Linux
Linux linux Kernel
References () https://git.kernel.org/stable/c/0cf7aaff290cdc4d7cee683d4a18138b0dacac48 - () https://git.kernel.org/stable/c/0cf7aaff290cdc4d7cee683d4a18138b0dacac48 - Patch
References () https://git.kernel.org/stable/c/10f3b29c65bb2fe0d47c2945cd0b4087be1c5218 - () https://git.kernel.org/stable/c/10f3b29c65bb2fe0d47c2945cd0b4087be1c5218 - Patch
References () https://git.kernel.org/stable/c/3f4d5e727aeaa610688d46c9f101f78b7f712583 - () https://git.kernel.org/stable/c/3f4d5e727aeaa610688d46c9f101f78b7f712583 - Patch
References () https://git.kernel.org/stable/c/41f7c4f85d402043687e863627a1a84fa867c62d - () https://git.kernel.org/stable/c/41f7c4f85d402043687e863627a1a84fa867c62d - Patch
References () https://git.kernel.org/stable/c/5c25a3040bc0486c41a7b63a1fb0de7cdb846ad7 - () https://git.kernel.org/stable/c/5c25a3040bc0486c41a7b63a1fb0de7cdb846ad7 - Patch
References () https://git.kernel.org/stable/c/aaf61a312af63e1cfe2264c4c5b8cd4ea3626025 - () https://git.kernel.org/stable/c/aaf61a312af63e1cfe2264c4c5b8cd4ea3626025 - Patch
References () https://git.kernel.org/stable/c/e412b3d178ea4bf746f6b8ee086761613704c6be - () https://git.kernel.org/stable/c/e412b3d178ea4bf746f6b8ee086761613704c6be - Patch
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 5.5

26 Feb 2025, 07:01

Type Values Removed Values Added
New CVE

Information

Published : 2025-02-26 07:01

Updated : 2025-10-21 12:18


NVD link : CVE-2022-49341

Mitre link : CVE-2022-49341

CVE.ORG link : CVE-2022-49341


JSON object : View

Products Affected

linux

  • linux_kernel