Linux Kernel up to 5.13.4 sync_file add_fence initialization

Summaryinfo

A vulnerability has been found in Linux Kernel up to 4.14.240/4.19.198/5.4.134/5.10.52/5.13.4 and classified as problematic. This vulnerability affects the function add_fence of the component sync_file. The manipulation leads to initialization. This vulnerability is traded as CVE-2021-47305. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 4.14.240/4.19.198/5.4.134/5.10.52/5.13.4. It has been rated as problematic. This issue affects the function add_fence of the component sync_file. The manipulation with an unknown input leads to a initialization vulnerability. Using CWE to declare the problem leads to CWE-665. The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: dma-buf/sync_file: Don't leak fences on merge failure Each add_fence() call does a dma_fence_get() on the relevant fence. In the error path, we weren't calling dma_fence_put() so all those fences got leaked. Also, in the krealloc_array failure case, we weren't freeing the fences array. Instead, ensure that i and fences are always zero-initialized and dma_fence_put() all the fences and kfree(fences) on every error path.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2021-47305 since 05/21/2024. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 4.14.241, 4.19.199, 5.4.135, 5.10.53 or 5.13.5 eliminates this vulnerability. Applying the patch 19f51c252933/e0355a0ad31a/41f45e91c92c/0d514185ae79/19edcd97727a/ffe000217c50 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

• 4.14.240
• 4.19.198
• 5.4.134
• 5.10.0
• 5.10.1
• 5.10.2
• 5.10.3
• 5.10.4
• 5.10.5
• 5.10.6
• 5.10.7
• 5.10.8
• 5.10.9
• 5.10.10
• 5.10.11
• 5.10.12
• 5.10.13
• 5.10.14
• 5.10.15
• 5.10.16
• 5.10.17
• 5.10.18
• 5.10.19
• 5.10.20
• 5.10.21
• 5.10.22
• 5.10.23
• 5.10.24
• 5.10.25
• 5.10.26
• 5.10.27
• 5.10.28
• 5.10.29
• 5.10.30
• 5.10.31
• 5.10.32
• 5.10.33
• 5.10.34
• 5.10.35
• 5.10.36
• 5.10.37
• 5.10.38
• 5.10.39
• 5.10.40
• 5.10.41
• 5.10.42
• 5.10.43
• 5.10.44
• 5.10.45
• 5.10.46
• 5.10.47
• 5.10.48
• 5.10.49
• 5.10.50
• 5.10.51
• 5.10.52
• 5.13.0
• 5.13.1
• 5.13.2
• 5.13.3
• 5.13.4

License

• open-source

Website

• Vendor: https://www.kernel.org/

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