CVE-2022-49840

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2022-49840
In the Linux kernel, the following vulnerability has been resolved: bpf, test_run: Fix alignment problem in bpf_prog_test_run_skb() We got a syzkaller problem because of aarch64 alignment fault if KFENCE enabled. When the size from user bpf program is an odd number, like 399, 407, etc, it will cause the struct skb_shared_info's unaligned access. As seen below: BUG: KFENCE: use-after-free read in __skb_clone+0x23c/0x2a0 net/core/skbuff.c:1032 Use-after-free read at 0xffff6254fffac077 (in kfence-#213): __lse_atomic_add arch/arm64/include/asm/atomic_lse.h:26 [inline] arch_atomic_add arch/arm64/include/asm/atomic.h:28 [inline] arch_atomic_inc include/linux/atomic-arch-fallback.h:270 [inline] atomic_inc include/asm-generic/atomic-instrumented.h:241 [inline] __skb_clone+0x23c/0x2a0 net/core/skbuff.c:1032 skb_clone+0xf4/0x214 net/core/skbuff.c:1481 ____bpf_clone_redirect net/core/filter.c:2433 [inline] bpf_clone_redirect+0x78/0x1c0 net/core/filter.c:2420 bpf_prog_d3839dd9068ceb51+0x80/0x330 bpf_dispatcher_nop_func include/linux/bpf.h:728 [inline] bpf_test_run+0x3c0/0x6c0 net/bpf/test_run.c:53 bpf_prog_test_run_skb+0x638/0xa7c net/bpf/test_run.c:594 bpf_prog_test_run kernel/bpf/syscall.c:3148 [inline] __do_sys_bpf kernel/bpf/syscall.c:4441 [inline] __se_sys_bpf+0xad0/0x1634 kernel/bpf/syscall.c:4381 kfence-#213: 0xffff6254fffac000-0xffff6254fffac196, size=407, cache=kmalloc-512 allocated by task 15074 on cpu 0 at 1342.585390s: kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:675 [inline] bpf_test_init.isra.0+0xac/0x290 net/bpf/test_run.c:191 bpf_prog_test_run_skb+0x11c/0xa7c net/bpf/test_run.c:512 bpf_prog_test_run kernel/bpf/syscall.c:3148 [inline] __do_sys_bpf kernel/bpf/syscall.c:4441 [inline] __se_sys_bpf+0xad0/0x1634 kernel/bpf/syscall.c:4381 __arm64_sys_bpf+0x50/0x60 kernel/bpf/syscall.c:4381 To fix the problem, we adjust @size so that (@size + @hearoom) is a multiple of SMP_CACHE_BYTES. So we make sure the struct skb_shared_info is aligned to a cache line.

7.8 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/047824a730699c6c66df43306b80f700c9dfc2fd Patch
https://git.kernel.org/stable/c/1b597f2d6a55e9f549989913860ad5170da04964 Patch
https://git.kernel.org/stable/c/730fb1ef974a13915bc7651364d8b3318891cd70 Patch
https://git.kernel.org/stable/c/7a704dbfd3735304e261f2787c52fbc7c3884736 Patch
https://git.kernel.org/stable/c/d3fd203f36d46aa29600a72d57a1b61af80e4a25 Patch
https://git.kernel.org/stable/c/e60f37a1d379c821c17b08f366412dce9ef3d99f Patch
https://git.kernel.org/stable/c/eaa8edd86514afac9deb9bf9a5053e74f37edf40 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:*:*:*:*:*:*:*:*
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:6.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc5:*:*:*:*:*:*
History

07 May 2025, 13:32

Type Values Removed Values Added
CPE cpe:2.3:o:linux:linux_kernel:6.1:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc3:*:*:*:*:*:*
CWE CWE-416
References () https://git.kernel.org/stable/c/047824a730699c6c66df43306b80f700c9dfc2fd - () https://git.kernel.org/stable/c/047824a730699c6c66df43306b80f700c9dfc2fd - Patch
References () https://git.kernel.org/stable/c/1b597f2d6a55e9f549989913860ad5170da04964 - () https://git.kernel.org/stable/c/1b597f2d6a55e9f549989913860ad5170da04964 - Patch
References () https://git.kernel.org/stable/c/730fb1ef974a13915bc7651364d8b3318891cd70 - () https://git.kernel.org/stable/c/730fb1ef974a13915bc7651364d8b3318891cd70 - Patch
References () https://git.kernel.org/stable/c/7a704dbfd3735304e261f2787c52fbc7c3884736 - () https://git.kernel.org/stable/c/7a704dbfd3735304e261f2787c52fbc7c3884736 - Patch
References () https://git.kernel.org/stable/c/d3fd203f36d46aa29600a72d57a1b61af80e4a25 - () https://git.kernel.org/stable/c/d3fd203f36d46aa29600a72d57a1b61af80e4a25 - Patch
References () https://git.kernel.org/stable/c/e60f37a1d379c821c17b08f366412dce9ef3d99f - () https://git.kernel.org/stable/c/e60f37a1d379c821c17b08f366412dce9ef3d99f - Patch
References () https://git.kernel.org/stable/c/eaa8edd86514afac9deb9bf9a5053e74f37edf40 - () https://git.kernel.org/stable/c/eaa8edd86514afac9deb9bf9a5053e74f37edf40 - Patch
First Time Linux linux Kernel
Linux
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 7.8

02 May 2025, 13:53

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: bpf, test_run: Se solucionó un problema de alineación en bpf_prog_test_run_skb(). Se detectó un problema en syzkaller debido a un fallo de alineación de aarch64 si KFENCE estaba habilitado. Cuando el tamaño del programa bpf del usuario es un número impar, como 399, 407, etc., se produce un acceso no alineado a la estructura skb_shared_info. Como se ve a continuación: ERROR: KFENCE: lectura de use-after-free en __skb_clone+0x23c/0x2a0 net/core/skbuff.c:1032 Lectura de use-after-free en 0xffff6254fffac077 (en kfence-#213): __lse_atomic_add arch/arm64/include/asm/atomic_lse.h:26 [en línea] arch_atomic_add arch/arm64/include/asm/atomic.h:28 [en línea] arch_atomic_inc include/linux/atomic-arch-fallback.h:270 [en línea] atomic_inc include/asm-generic/atomic-instrumented.h:241 [en línea] __skb_clone+0x23c/0x2a0 net/core/skbuff.c:1032 skb_clone+0xf4/0x214 net/core/skbuff.c:1481 ____bpf_clone_redirect net/core/filter.c:2433 [en línea] bpf_clone_redirect+0x78/0x1c0 net/core/filter.c:2420 bpf_prog_d3839dd9068ceb51+0x80/0x330 bpf_dispatcher_nop_func include/linux/bpf.h:728 [en línea] bpf_test_run+0x3c0/0x6c0 net/bpf/test_run.c:53 bpf_prog_test_run_skb+0x638/0xa7c net/bpf/test_run.c:594 bpf_prog_test_run kernel/bpf/syscall.c:3148 [en línea] __do_sys_bpf kernel/bpf/syscall.c:4441 [en línea] __se_sys_bpf+0xad0/0x1634 kernel/bpf/syscall.c:4381 kfence-#213: 0xffff6254fffac000-0xffff6254fffac196, tamaño=407, caché=kmalloc-512 asignado por la tarea 15074 en la CPU 0 a las 1342.585390 s: kmalloc include/linux/slab.h:568 [en línea] kzalloc include/linux/slab.h:675 [en línea] bpf_test_init.isra.0+0xac/0x290 Para corregir el problema, ajustamos @size de modo que (@size + @hearoom) sea un múltiplo de SMP_CACHE_BYTES. Así nos aseguramos de que la estructura skb_shared_info esté alineada con una línea de caché.

01 May 2025, 15:16

Type Values Removed Values Added
New CVE
Information

Published : 2025-05-01 15:16

Updated : 2025-05-07 13:32

NVD link : CVE-2022-49840

Mitre link : CVE-2022-49840

CVE.ORG link : CVE-2022-49840

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-416

Use After Free