NULL Pointer Dereference Affecting kernel package, versions *


Severity

Recommended
low

Based on CentOS security rating.

Threat Intelligence

EPSS
0.05% (18th percentile)

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  • Snyk IDSNYK-CENTOS7-KERNEL-7003817
  • published22 May 2024
  • disclosed21 May 2024

Introduced: 21 May 2024

CVE-2021-47333  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

There is no fixed version for Centos:7 kernel.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel package and not the kernel package as distributed by Centos. See How to fix? for Centos:7 relevant fixed versions and status.

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

misc: alcor_pci: fix null-ptr-deref when there is no PCI bridge

There is an issue with the ASPM(optional) capability checking function. A device might be attached to root complex directly, in this case, bus->self(bridge) will be NULL, thus priv->parent_pdev is NULL. Since alcor_pci_init_check_aspm(priv->parent_pdev) checks the PCI link's ASPM capability and populate parent_cap_off, which will be used later by alcor_pci_aspm_ctrl() to dynamically turn on/off device, what we can do here is to avoid checking the capability if we are on the root complex. This will make pdev_cap_off 0 and alcor_pci_aspm_ctrl() will simply return when bring called, effectively disable ASPM for the device.

[ 1.246492] BUG: kernel NULL pointer dereference, address: 00000000000000c0 [ 1.248731] RIP: 0010:pci_read_config_byte+0x5/0x40 [ 1.253998] Call Trace: [ 1.254131] ? alcor_pci_find_cap_offset.isra.0+0x3a/0x100 [alcor_pci] [ 1.254476] alcor_pci_probe+0x169/0x2d5 [alcor_pci]

CVSS Scores

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