CVE-2023-52854
padata: Fix refcnt handling in padata_free_shell()
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
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`.
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`.
CVSS Scores
SSVC
- Decision:Track
Timeline
- 2024-05-21 CVE Reserved
- 2024-05-21 CVE Published
- 2024-05-22 EPSS Updated
- 2024-12-19 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
CAPEC
References (14)
URL | Tag | Source |
---|---|---|
https://git.kernel.org/stable/c/07928d9bfc81640bab36f5190e8725894d93b659 | Vuln. Introduced | |
https://git.kernel.org/stable/c/13721e447acc2b82c19cf72e9e6c4291c77693ed | Vuln. Introduced | |
https://git.kernel.org/stable/c/7a2ccb65f90168edc2348495bb56093c466ffa39 | Vuln. Introduced | |
https://git.kernel.org/stable/c/928cf3d733c4efc221e1a78b14cb2ee066627260 | Vuln. Introduced | |
https://git.kernel.org/stable/c/c9da8ee1491719001a444f4af688b75e72b58418 | Vuln. Introduced | |
https://git.kernel.org/stable/c/dc34710a7aba5207e7cb99d11588c04535b3c53d | Vuln. Introduced | |
https://git.kernel.org/stable/c/5fefc9b3e3584a1ce98da27c38e1b8dda1939d74 | Vuln. Introduced | |
https://git.kernel.org/stable/c/26daf8e6515c2dcd25d235468420b9f46e0acdac | Vuln. Introduced |
URL | Date | SRC |
---|
URL | Date | SRC |
---|
Affected Vendors, Products, and Versions
Vendor | Product | Version | Other | Status | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.6 < 5.10.201 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.6 < 5.10.201" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.6 < 5.15.139 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.6 < 5.15.139" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.6 < 6.1.63 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.6 < 6.1.63" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.6 < 6.5.12 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.6 < 6.5.12" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.6 < 6.6.2 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.6 < 6.6.2" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.6 < 6.7 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.6 < 6.7" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | 3.16.84 Search vendor "Linux" for product "Linux Kernel" and version "3.16.84" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | 4.4.215 Search vendor "Linux" for product "Linux Kernel" and version "4.4.215" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | 4.9.215 Search vendor "Linux" for product "Linux Kernel" and version "4.9.215" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | 4.14.172 Search vendor "Linux" for product "Linux Kernel" and version "4.14.172" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | 4.19.103 Search vendor "Linux" for product "Linux Kernel" and version "4.19.103" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | 5.4.19 Search vendor "Linux" for product "Linux Kernel" and version "5.4.19" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | 5.5.3 Search vendor "Linux" for product "Linux Kernel" and version "5.5.3" | en |
Affected
|