Linux Kernel up to 5.17.3 da850_evm_config_emac null pointer dereference

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 5.17.3. This issue affects the function da850_evm_config_emac. The manipulation results in null pointer dereference. This vulnerability is reported as CVE-2021-47631. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.17.3. It has been classified as critical. Affected is the function da850_evm_config_emac. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

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.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2021-47631 since 02/26/2025. The exploitability is told to be difficult. There are known technical details, but no exploit is available.

Upgrading to version 4.9.311, 4.14.276, 4.19.239, 5.4.190, 5.10.112, 5.15.35 or 5.17.4 eliminates this vulnerability. Applying the patch c06f476e5b74bcabb8c4a2fba55864a37e62843b/a12b356d45cbb6e8a1b718d1436b3d6239a862f3/c64e2ed5cc376e137e572babfd2edc38b2cfb61b/89931d4762572aaee6edbe5673d41f8082de110f/0a312ec66a03133d28570f07bc52749ccfef54da/0940795c6834fbe7705acc5c3d4b2f7a5f67527a/c5628533a3ece64235d04fe11ec44d2be99e423d/83a1cde5c74bfb44b49cb2a940d044bb2380f4ea is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.9.310
• 4.14.275
• 4.19.238
• 5.4.189
• 5.10.111
• 5.15.0
• 5.15.1
• 5.15.2
• 5.15.3
• 5.15.4
• 5.15.5
• 5.15.6
• 5.15.7
• 5.15.8
• 5.15.9
• 5.15.10
• 5.15.11
• 5.15.12
• 5.15.13
• 5.15.14
• 5.15.15
• 5.15.16
• 5.15.17
• 5.15.18
• 5.15.19
• 5.15.20
• 5.15.21
• 5.15.22
• 5.15.23
• 5.15.24
• 5.15.25
• 5.15.26
• 5.15.27
• 5.15.28
• 5.15.29
• 5.15.30
• 5.15.31
• 5.15.32
• 5.15.33
• 5.15.34
• 5.17.0
• 5.17.1
• 5.17.2
• 5.17.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

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