CVE-2021-47631 - Vulnerability Details

- ARM: davinci: da850-evm: Avoid NULL pointer dereference

Description

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

ARM: davinci: da850-evm: Avoid NULL pointer dereference

With newer versions of GCC, there is a panic in da850_evm_config_emac()
when booting multi_v5_defconfig in QEMU under the palmetto-bmc machine:

Unable to handle kernel NULL pointer dereference at virtual address 00000020
pgd = (ptrval)
[00000020] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 5.15.0 #1
Hardware name: Generic DT based system
PC is at da850_evm_config_emac+0x1c/0x120
LR is at do_one_initcall+0x50/0x1e0

The emac_pdata pointer in soc_info is NULL because davinci_soc_info only
gets populated on davinci machines but da850_evm_config_emac() is called
on all machines via device_initcall().

Move the rmii_en assignment below the machine check so that it is only
dereferenced when running on a supported SoC.

Published: 2025-02-26

Score: 5.5 Medium

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`bae105879f2f2404155da6f50b3636193d228a62`	affected	< c06f476e5b74bcabb8c4a2fba55864a37e62843b
`bae105879f2f2404155da6f50b3636193d228a62`	affected	< a12b356d45cbb6e8a1b718d1436b3d6239a862f3
`bae105879f2f2404155da6f50b3636193d228a62`	affected	< c64e2ed5cc376e137e572babfd2edc38b2cfb61b
`bae105879f2f2404155da6f50b3636193d228a62`	affected	< 89931d4762572aaee6edbe5673d41f8082de110f
`bae105879f2f2404155da6f50b3636193d228a62`	affected	< 0a312ec66a03133d28570f07bc52749ccfef54da
`bae105879f2f2404155da6f50b3636193d228a62`	affected	< 0940795c6834fbe7705acc5c3d4b2f7a5f67527a
`bae105879f2f2404155da6f50b3636193d228a62`	affected	< c5628533a3ece64235d04fe11ec44d2be99e423d
`bae105879f2f2404155da6f50b3636193d228a62`	affected	< 83a1cde5c74bfb44b49cb2a940d044bb2380f4ea

Linux

affected

Version	Status	Constraints
`2.6.33`	affected	—
`0`	unaffected	< 2.6.33
`4.9.311`	unaffected	≤ 4.9.*
`4.14.276`	unaffected	≤ 4.14.*
`4.19.239`	unaffected	≤ 4.19.*
`5.4.190`	unaffected	≤ 5.4.*
`5.10.112`	unaffected	≤ 5.10.*
`5.15.35`	unaffected	≤ 5.15.*
`5.17.4`	unaffected	≤ 5.17.*
`5.18`	unaffected	≤ *

Configuration 1 [-]

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel:5.18:rc1::::::
	cpe:2.3:o:linux:linux_kernel:5.18:rc2::::::

No data.

No data available yet.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

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Advisories

Source	ID	Title
EUVD	EUVD-2021-34673	In the Linux kernel, the following vulnerability has been resolved: ARM: davinci: da850-evm: Avoid NULL pointer dereference With newer versions of GCC, there is a panic in da850_evm_config_emac() when booting multi_v5_defconfig in QEMU under the palmetto-bmc machine: Unable to handle kernel NULL pointer dereference at virtual address 00000020 pgd = (ptrval) [00000020] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.15.0 #1 Hardware name: Generic DT based system PC is at da850_evm_config_emac+0x1c/0x120 LR is at do_one_initcall+0x50/0x1e0 The emac_pdata pointer in soc_info is NULL because davinci_soc_info only gets populated on davinci machines but da850_evm_config_emac() is called on all machines via device_initcall(). Move the rmii_en assignment below the machine check so that it is only dereferenced when running on a supported SoC.

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00008.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/0940795c6834fbe7705acc5c3d4b2f7a5f67527a
https://git.kernel.org/stable/c/0a312ec66a03133d28570f07bc52749ccfef54da
https://git.kernel.org/stable/c/83a1cde5c74bfb44b49cb2a940d044bb2380f4ea
https://git.kernel.org/stable/c/89931d4762572aaee6edbe5673d41f8082de110f
https://git.kernel.org/stable/c/a12b356d45cbb6e8a1b718d1436b3d6239a862f3
https://git.kernel.org/stable/c/c06f476e5b74bcabb8c4a2fba55864a37e62843b
https://git.kernel.org/stable/c/c5628533a3ece64235d04fe11ec44d2be99e423d
https://git.kernel.org/stable/c/c64e2ed5cc376e137e572babfd2edc38b2cfb61b
https://lore.kernel.org/linux-cve-announce/2025022643-CVE-2021-47631-bcc8@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2021-47631
https://www.cve.org/CVERecord?id=CVE-2021-47631

History

Mon, 21 Apr 2025 02:45:00 +0000

Type	Values Removed	Values Added
Metrics	threat_severity `Low`	threat_severity `Moderate`

Tue, 18 Mar 2025 20:00:00 +0000

Type	Values Removed	Values Added
First Time appeared		Linux Linux linux Kernel
Weaknesses		CWE-476
CPEs		cpe:2.3:o:linux:linux_kernel:::::::: cpe:2.3:o:linux:linux_kernel:5.18:rc1:::::: cpe:2.3:o:linux:linux_kernel:5.18:rc2::::::
Vendors & Products		Linux Linux linux Kernel

Fri, 28 Feb 2025 14:00:00 +0000

Type	Values Removed	Values Added
References		https://lore.kernel.org/linux-cve-announce/2025022643-CVE-2021-47631-bcc8@gregkh/T https://nvd.nist.gov/vuln/detail/CVE-2021-47631 https://www.cve.org/CVERecord?id=CVE-2021-47631
Metrics	threat_severity `None`	cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}` threat_severity `Low`

Wed, 26 Feb 2025 02:15:00 +0000

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: ARM: davinci: da850-evm: Avoid NULL pointer dereference With newer versions of GCC, there is a panic in da850_evm_config_emac() when booting multi_v5_defconfig in QEMU under the palmetto-bmc machine: Unable to handle kernel NULL pointer dereference at virtual address 00000020 pgd = (ptrval) [00000020] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.15.0 #1 Hardware name: Generic DT based system PC is at da850_evm_config_emac+0x1c/0x120 LR is at do_one_initcall+0x50/0x1e0 The emac_pdata pointer in soc_info is NULL because davinci_soc_info only gets populated on davinci machines but da850_evm_config_emac() is called on all machines via device_initcall(). Move the rmii_en assignment below the machine check so that it is only dereferenced when running on a supported SoC.
Title		ARM: davinci: da850-evm: Avoid NULL pointer dereference
References		https://git.kernel.org/stable/c/0940795c6834fbe7705acc5c3d4b2f7a5f67527a https://git.kernel.org/stable/c/0a312ec66a03133d28570f07bc52749ccfef54da https://git.kernel.org/stable/c/83a1cde5c74bfb44b49cb2a940d044bb2380f4ea https://git.kernel.org/stable/c/89931d4762572aaee6edbe5673d41f8082de110f https://git.kernel.org/stable/c/a12b356d45cbb6e8a1b718d1436b3d6239a862f3 https://git.kernel.org/stable/c/c06f476e5b74bcabb8c4a2fba55864a37e62843b https://git.kernel.org/stable/c/c5628533a3ece64235d04fe11ec44d2be99e423d https://git.kernel.org/stable/c/c64e2ed5cc376e137e572babfd2edc38b2cfb61b

Subscriptions

Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-02-26T01:54:07.513Z

Updated: 2026-05-11T13:58:07.851Z

Reserved: 2025-02-26T01:48:21.518Z

Link: CVE-2021-47631

Vulnrichment

No data.

NVD

Status : Modified

Published: 2025-02-26T06:37:04.400

Modified: 2025-10-01T20:15:39.100

Link: CVE-2021-47631

Redhat

Severity : Moderate

Publid Date: 2025-02-26T00:00:00Z

Links: CVE-2021-47631 - Bugzilla

OpenCVE Enrichment

No data.

Weaknesses

CWE-476

Tracking

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Subscriptions

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