// For flags

CVE-2021-47005

PCI: endpoint: Fix NULL pointer dereference for ->get_features()

Severity Score

"-"
*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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

PCI: endpoint: Fix NULL pointer dereference for ->get_features()

get_features ops of pci_epc_ops may return NULL, causing NULL pointer
dereference in pci_epf_test_alloc_space function. Let us add a check for
pci_epc_feature pointer in pci_epf_test_bind before we access it to avoid
any such NULL pointer dereference and return -ENOTSUPP in case
pci_epc_feature is not found.

When the patch is not applied and EPC features is not implemented in the
platform driver, we see the following dump due to kernel NULL pointer
dereference.

Call trace:
pci_epf_test_bind+0xf4/0x388
pci_epf_bind+0x3c/0x80
pci_epc_epf_link+0xa8/0xcc
configfs_symlink+0x1a4/0x48c
vfs_symlink+0x104/0x184
do_symlinkat+0x80/0xd4
__arm64_sys_symlinkat+0x1c/0x24
el0_svc_common.constprop.3+0xb8/0x170
el0_svc_handler+0x70/0x88
el0_svc+0x8/0x640
Code: d2800581 b9403ab9 f9404ebb 8b394f60 (f9400400)
---[ end trace a438e3c5a24f9df0 ]---

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: PCI: endpoint: corrigió la desreferencia del puntero NULL para ->get_features() las operaciones get_features de pci_epc_ops pueden devolver NULL, lo que provoca la desreferencia del puntero NULL en la función pci_epf_test_alloc_space. Agreguemos una verificación del puntero pci_epc_feature en pci_epf_test_bind antes de acceder a él para evitar dicha desreferencia del puntero NULL y devolvamos -ENOTSUPP en caso de que no se encuentre pci_epc_feature. Cuando no se aplica el parche y las funciones de EPC no se implementan en el controlador de la plataforma, vemos el siguiente volcado debido a la desreferencia del puntero NULL del kernel. Rastreo de llamadas: pci_epf_test_bind+0xf4/0x388 pci_epf_bind+0x3c/0x80 pci_epc_epf_link+0xa8/0xcc configfs_symlink+0x1a4/0x48c vfs_symlink+0x104/0x184 do_symlinkat+0x80/0xd4 __arm64_sys _symlinkat+0x1c/0x24 el0_svc_common.constprop.3+0xb8/0x170 el0_svc_handler+0x70 /0x88 el0_svc+0x8/0x640 Código: d2800581 b9403ab9 f9404ebb 8b394f60 (f9400400) ---[ final de seguimiento a438e3c5a24f9df0 ]---

*Credits: N/A
CVSS Scores
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Scope
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Confidentiality
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Integrity
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Availability
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* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-02-27 CVE Reserved
  • 2024-02-28 CVE Published
  • 2024-02-29 EPSS Updated
  • 2024-08-04 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
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"
 >= 5.1 < 5.10.38
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.1 < 5.10.38"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.1 < 5.11.22
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.1 < 5.11.22"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.1 < 5.12.5
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.1 < 5.12.5"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.1 < 5.13
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.1 < 5.13"
en
Affected