CVE-2023-52854

In the Linux kernel, the following vulnerability has been resolved: padata: Fix refcnt handling in padata_free_shell() In a high-load arm64 environment, the pcrypt_aead01 test in LTP can lead to system UAF (Use-After-Free) issues. Due to the lengthy analysis of the pcrypt_aead01 function call, I'll describe the problem scenario using a simplified model: Suppose there's a user of padata named `user_function` that adheres to the padata requirement of calling `padata_free_shell` after `serial()` has been invoked, as demonstrated in the following code: ```c struct request { struct padata_priv padata; struct completion *done; }; void parallel(struct padata_priv *padata) { do_something(); } void serial(struct padata_priv *padata) { struct request *request = container_of(padata, struct request, padata); complete(request->done); } void user_function() { DECLARE_COMPLETION(done) padata->parallel = parallel; padata->serial = serial; padata_do_parallel(); wait_for_completion(&done); padata_free_shell(); } ``` In the corresponding padata.c file, there's the following code: ```c static void padata_serial_worker(struct work_struct *serial_work) { ... cnt = 0; while (!list_empty(&local_list)) { ... padata->serial(padata); cnt++; } local_bh_enable(); if (refcount_sub_and_test(cnt, &pd->refcnt)) padata_free_pd(pd); } ``` Because of the high system load and the accumulation of unexecuted softirq at this moment, `local_bh_enable()` in padata takes longer to execute than usual. Subsequently, when accessing `pd->refcnt`, `pd` has already been released by `padata_free_shell()`, resulting in a UAF issue with `pd->refcnt`. The fix is straightforward: add `refcount_dec_and_test` before calling `padata_free_pd` in `padata_free_shell`.
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:*:*:*:*:*:*:*:*
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:*:*:*:*:*:*:*:*

History

03 Feb 2025, 16:13

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/0dd34a7ad395dbcf6ae60e48e9786050e25b9bc5 - () https://git.kernel.org/stable/c/0dd34a7ad395dbcf6ae60e48e9786050e25b9bc5 - Patch
References () https://git.kernel.org/stable/c/1734a79e951914f1db2c65e635012a35db1c674b - () https://git.kernel.org/stable/c/1734a79e951914f1db2c65e635012a35db1c674b - Patch
References () https://git.kernel.org/stable/c/1e901bcb8af19416b65f5063a4af7996e5a51d7f - () https://git.kernel.org/stable/c/1e901bcb8af19416b65f5063a4af7996e5a51d7f - Patch
References () https://git.kernel.org/stable/c/41aad9d6953984d134fc50f631f24ef476875d4d - () https://git.kernel.org/stable/c/41aad9d6953984d134fc50f631f24ef476875d4d - Patch
References () https://git.kernel.org/stable/c/7ddc21e317b360c3444de3023bcc83b85fabae2f - () https://git.kernel.org/stable/c/7ddc21e317b360c3444de3023bcc83b85fabae2f - Patch
References () https://git.kernel.org/stable/c/c7c26d0ef5d20f00dbb2ae3befcabbe0efa77275 - () https://git.kernel.org/stable/c/c7c26d0ef5d20f00dbb2ae3befcabbe0efa77275 - Patch
CWE CWE-416
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
First Time Linux
Linux linux Kernel
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.8

21 Nov 2024, 08:40

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/0dd34a7ad395dbcf6ae60e48e9786050e25b9bc5 - () https://git.kernel.org/stable/c/0dd34a7ad395dbcf6ae60e48e9786050e25b9bc5 -
References () https://git.kernel.org/stable/c/1734a79e951914f1db2c65e635012a35db1c674b - () https://git.kernel.org/stable/c/1734a79e951914f1db2c65e635012a35db1c674b -
References () https://git.kernel.org/stable/c/1e901bcb8af19416b65f5063a4af7996e5a51d7f - () https://git.kernel.org/stable/c/1e901bcb8af19416b65f5063a4af7996e5a51d7f -
References () https://git.kernel.org/stable/c/41aad9d6953984d134fc50f631f24ef476875d4d - () https://git.kernel.org/stable/c/41aad9d6953984d134fc50f631f24ef476875d4d -
References () https://git.kernel.org/stable/c/7ddc21e317b360c3444de3023bcc83b85fabae2f - () https://git.kernel.org/stable/c/7ddc21e317b360c3444de3023bcc83b85fabae2f -
References () https://git.kernel.org/stable/c/c7c26d0ef5d20f00dbb2ae3befcabbe0efa77275 - () https://git.kernel.org/stable/c/c7c26d0ef5d20f00dbb2ae3befcabbe0efa77275 -
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: padata: corrige el manejo de refcnt en padata_free_shell(). En un entorno arm64 de alta carga, la prueba pcrypt_aead01 en LTP puede provocar problemas de UAF (Use-After-Free) del sistema. Debido al extenso análisis de la llamada a la función pcrypt_aead01, describiré el escenario del problema usando un modelo simplificado: supongamos que hay un usuario de padata llamado `user_function` que cumple con el requisito de padata de llamar a `padata_free_shell` después de `serial()`. ha sido invocado, como se demuestra en el siguiente código: ```c struct request { struct padata_priv padata; finalización de la estructura *hecho; }; void paralelo(struct padata_priv *padata) { hacer_algo(); } void serial(struct padata_priv *padata) { solicitud de estructura *request = container_of(padata, solicitud de estructura, padata); completar(solicitud->hecho); } void user_function() { DECLARE_COMPLETION(hecho) padata->parallel = parallel; padata->serial = serial; padata_do_parallel(); wait_for_completion(&hecho); padata_free_shell(); } ``` En el archivo padata.c correspondiente, hay el siguiente código: ```c static void padata_serial_worker(struct work_struct *serial_work) { ... cnt = 0; while (!list_empty(&local_list)) { ... padata->serial(padata); cnt++; } local_bh_enable(); if (refcount_sub_and_test(cnt, &pd->refcnt)) padata_free_pd(pd); } ``` Debido a la alta carga del sistema y la acumulación de software no ejecutado en este momento, `local_bh_enable()` en padata tarda más de lo habitual en ejecutarse. Posteriormente, al acceder a `pd->refcnt`, `pd` ya ha sido liberado por `padata_free_shell()`, lo que genera un problema de UAF con `pd->refcnt`. La solución es sencilla: agregue `refcount_dec_and_test` antes de llamar a `padata_free_pd` en `padata_free_shell`.

21 May 2024, 16:15

Type Values Removed Values Added
New CVE

Information

Published : 2024-05-21 16:15

Updated : 2025-02-03 16:13


NVD link : CVE-2023-52854

Mitre link : CVE-2023-52854

CVE.ORG link : CVE-2023-52854


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-416

Use After Free