CVE-2021-47455: ptp: Fix possible memory leak in ptp_clock_register()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-22 · updated 2026-06-17
Weakness: CWE-401

Description

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: [<00000000312ed458>] __kmalloc_track_caller+0x19f/0x3a0 [<0000000079f6e2ff>] kvasprintf+0xb5/0x150 [<0000000026aae54f>] kvasprintf_const+0x60/0x190 [<00000000f323a5f7>] kobject_set_name_vargs+0x56/0x150 [<000000004e35abdd>] dev_set_name+0xc0/0x100 [<00000000f20cfe25>] ptp_clock_register+0x9f4/0xd30 [ptp] [<000000008bb9f0de>] 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().

Affected products

Linux kernel: from 3.16.83 before 3.17; from 4.4.224 before 4.5; from 4.9.224 before 4.10; from 4.14.162 before 4.15; from 4.19.93 before 4.20; from 5.4.8 before 5.14.15 — fixed in 3.17, 4.10, 4.15, 4.20, 4.5, 5.14.15

How to fix

Upgrade to a fixed version: Linux kernel 3.17, 4.10, 4.15, 4.20. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2021-47455 or the next vulnerability affects your stack