CVE-2021-47305

MEDIUM
Published May 21, 2024 Modified May 12, 2025 CWE-617

Description

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.

Is your site exposed to CVE-2021-47305?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.5
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-617 CWE-617

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Advisories & Patches

https://git.kernel.org/stable/c/0d514185ae792d3a1903c8e1a83899aa996705ce https://git.kernel.org/stable/c/19edcd97727aae9362444a859a24d99a8730cb27 https://git.kernel.org/stable/c/19f51c2529339280d2c8c6427cd3e21ddf1ac3f8 https://git.kernel.org/stable/c/41f45e91c92c8480242ea448d54e28c753b13902 https://git.kernel.org/stable/c/e0355a0ad31a1d677b2a4514206de4902bd550e8 https://git.kernel.org/stable/c/ffe000217c5068c5da07ccb1c0f8cce7ad767435 https://git.kernel.org/stable/c/0d514185ae792d3a1903c8e1a83899aa996705ce https://git.kernel.org/stable/c/19edcd97727aae9362444a859a24d99a8730cb27 https://git.kernel.org/stable/c/19f51c2529339280d2c8c6427cd3e21ddf1ac3f8 https://git.kernel.org/stable/c/41f45e91c92c8480242ea448d54e28c753b13902 https://git.kernel.org/stable/c/e0355a0ad31a1d677b2a4514206de4902bd550e8 https://git.kernel.org/stable/c/ffe000217c5068c5da07ccb1c0f8cce7ad767435

Frequently Asked Questions

What is CVE-2021-47305? +
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 has a CVSS v3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2021-47305? +
CVE-2021-47305 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
What products are affected by CVE-2021-47305? +
CVE-2021-47305 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2021-47305? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-13058

An authenticated user with basic write privileges can cause the mongod process to terminate abnormally by sending a crafted transaction …
CVE-2025-4321

In a Bluetooth device, using RS9116-WiseConnect SDK experiences a Denial of Service, if it receives malformed L2CAP packets, only hard …
CVE-2025-34458

wb2osz/direwolf (Dire Wolf) versions up to and including 1.8, prior to commit 3658a87, contain a reachable assertion vulnerability in the …
CVE-2026-29116

A vulnerability has been found in some Dahua products could allow an unauthenticated remote attacker to send a specially crafted …
CVE-2026-35058

Improper validation of packet length during tls-crypt-v2 key extraction in OpenVPN 2.6.0 through 2.6.19 and 2.7_alpha1 through 2.7.1 allows authenticated …
CVE-2026-29115

A vulnerability has been found in some Dahua products could allow an authenticated remote attacker to send a specially crafted …

Don't wait for an exploit

Scan your website for vulnerabilities like CVE-2021-47305 — free, no signup required.