CVE-2021-47333
Linux Alcor PCI Null Pointer Dereference Vulnerability
Description
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]
INFO
Published Date :
May 21, 2024, 3:15 p.m.
Last Modified :
April 2, 2025, 2:32 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-47333.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-47333 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47333 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Apr. 02, 2025
Action Type Old Value New Value Added CWE CWE-476 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.5 up to (excluding) 5.10.52 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.12.19 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.13 up to (excluding) 5.13.4 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions up to (excluding) 5.4.134 Added Reference Type CVE: https://git.kernel.org/stable/c/09d154990ca82d14aed2b72796f6c8845e2e605d Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/09d154990ca82d14aed2b72796f6c8845e2e605d Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/3ce3e45cc333da707d4d6eb433574b990bcc26f5 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/3ce3e45cc333da707d4d6eb433574b990bcc26f5 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/58f69684ba03e5b0e0a3ae844a845280c0f06309 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/58f69684ba03e5b0e0a3ae844a845280c0f06309 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/717cf5ae52322ddbdf3ac2c584b34c5970b0d174 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/717cf5ae52322ddbdf3ac2c584b34c5970b0d174 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/d2639ffdcad463b358b6bef8645ff81715daffcb Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/d2639ffdcad463b358b6bef8645ff81715daffcb Types: Patch -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/09d154990ca82d14aed2b72796f6c8845e2e605d Added Reference https://git.kernel.org/stable/c/3ce3e45cc333da707d4d6eb433574b990bcc26f5 Added Reference https://git.kernel.org/stable/c/58f69684ba03e5b0e0a3ae844a845280c0f06309 Added Reference https://git.kernel.org/stable/c/717cf5ae52322ddbdf3ac2c584b34c5970b0d174 Added Reference https://git.kernel.org/stable/c/d2639ffdcad463b358b6bef8645ff81715daffcb -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 31, 2024
Action Type Old Value New Value Added CVSS V3.1 CISA-ADP AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 21, 2024
Action Type Old Value New Value Added Description 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] Added Reference kernel.org https://git.kernel.org/stable/c/d2639ffdcad463b358b6bef8645ff81715daffcb [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/58f69684ba03e5b0e0a3ae844a845280c0f06309 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/717cf5ae52322ddbdf3ac2c584b34c5970b0d174 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/09d154990ca82d14aed2b72796f6c8845e2e605d [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/3ce3e45cc333da707d4d6eb433574b990bcc26f5 [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47333 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47333
weaknesses.