Linux Kernel up to 5.14.14 ptp_clock_register memory leak

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.14.14. It has been rated as critical. This affects the function ptp_clock_register. This manipulation causes memory leak. This vulnerability is tracked as CVE-2021-47455. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.14.14. It has been declared as critical. Affected by this vulnerability is the function ptp_clock_register. The manipulation with an unknown input leads to a memory leak vulnerability. The CWE definition for the vulnerability is CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ptp: Fix possible memory leak in ptp_clock_register() I got memory leak as follows when doing fault injection test: unreferenced object 0xffff88800906c618 (size 8): comm "i2c-idt82p33931", pid 4421, jiffies 4294948083 (age 13.188s) hex dump (first 8 bytes): 70 74 70 30 00 00 00 00 ptp0.... backtrace: [] __kmalloc_track_caller+0x19f/0x3a0 [] kvasprintf+0xb5/0x150 [] kvasprintf_const+0x60/0x190 [] kobject_set_name_vargs+0x56/0x150 [] dev_set_name+0xc0/0x100 [] ptp_clock_register+0x9f4/0xd30 [ptp] [] idt82p33_probe.cold+0x8b6/0x1561 [ptp_idt82p33] When posix_clock_register() returns an error, the name allocated in dev_set_name() will be leaked, the put_device() should be used to give up the device reference, then the name will be freed in kobject_cleanup() and other memory will be freed in ptp_clock_release().

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2021-47455 since 05/21/2024. The exploitation appears to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 207773 (Oracle Linux 8 : kernel (ELSA-2024-7000)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.14.15 eliminates this vulnerability. Applying the patch 95c0a0c5ec88/4225fea1cb28 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.

The vulnerability is also documented in the vulnerability database at Tenable (207773). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.14.0
• 5.14.1
• 5.14.2
• 5.14.3
• 5.14.4
• 5.14.5
• 5.14.6
• 5.14.7
• 5.14.8
• 5.14.9
• 5.14.10
• 5.14.11
• 5.14.12
• 5.14.13
• 5.14.14

License

• open-source

Website

• Vendor: https://www.kernel.org/

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