CVE-2024-26785

iommufd: Fix protection fault in iommufd_test_syz_conv_iova

Severity Score

"-"

*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

In the Linux kernel, the following vulnerability has been resolved:

iommufd: Fix protection fault in iommufd_test_syz_conv_iova

Syzkaller reported the following bug:

general protection fault, probably for non-canonical address 0xdffffc0000000038: 0000 [#1] SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000001c0-0x00000000000001c7]
Call Trace:
lock_acquire
lock_acquire+0x1ce/0x4f0
down_read+0x93/0x4a0
iommufd_test_syz_conv_iova+0x56/0x1f0
iommufd_test_access_rw.isra.0+0x2ec/0x390
iommufd_test+0x1058/0x1e30
iommufd_fops_ioctl+0x381/0x510
vfs_ioctl
__do_sys_ioctl
__se_sys_ioctl
__x64_sys_ioctl+0x170/0x1e0
do_syscall_x64
do_syscall_64+0x71/0x140

This is because the new iommufd_access_change_ioas() sets access->ioas to
NULL during its process, so the lock might be gone in a concurrent racing
context.

Fix this by doing the same access->ioas sanity as iommufd_access_rw() and
iommufd_access_pin_pages() functions do.

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: iommufd: Se corrigió falla de protección en iommufd_test_syz_conv_iova Syzkaller informó el siguiente error: falla de protección general, probablemente para dirección no canónica 0xdffffc0000000038: 0000 [#1] SMP KASAN KASAN: null-ptr- deref en el rango [0x00000000000001c0-0x00000000000001c7] Seguimiento de llamadas: lock_acquire lock_acquire+0x1ce/0x4f0 down_read+0x93/0x4a0 iommufd_test_syz_conv_iova+0x56/0x1f0 iommufd_test_access_rw.isra. 0+0x2ec/0x390 iommufd_test+0x1058/0x1e30 iommufd_fops_ioctl+0x381/0x510 vfs_ioctl __do_sys_ioctl __se_sys_ioctl __x64_sys_ioctl +0x170/0x1e0 do_syscall_x64 do_syscall_64+0x71/0x140 Esto se debe a que el nuevo iommufd_access_change_ioas() establece access->ioas en NULL durante su proceso, por lo que el bloqueo podría desaparecer en un contexto de ejecución concurrente. Solucione este problema haciendo el mismo acceso->ioas cordura que hacen las funciones iommufd_access_rw() y iommufd_access_pin_pages().

*Credits: N/A

CVSS Scores

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-02-19 CVE Reserved
2024-04-04 CVE Published
2024-04-05 EPSS Updated
2024-08-02 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (3)

URL	Tag	Source
https://git.kernel.org/stable/c/9227da7816dd1a42e20d41e2244cb63c205477ca	Vuln. Introduced

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/fc719ecbca45c9c046640d72baddba3d83e0bc0b	2024-03-06
https://git.kernel.org/stable/c/cf7c2789822db8b5efa34f5ebcf1621bc0008d48	2024-02-26

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"				>= 6.6 < 6.7.9 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.6 < 6.7.9"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 6.6 < 6.8 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.6 < 6.8"		en		Affected