Linux Kernel up to 6.1.8 f_fs ffs_ep0_queue_wait use after free

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.1.8 and classified as critical. The impacted element is the function ffs_ep0_queue_wait of the component f_fs. This manipulation causes use after free. The identification of this vulnerability is CVE-2022-49755. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.8. It has been declared as critical. Affected by this vulnerability is the function ffs_ep0_queue_wait of the component f_fs. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Prevent race during ffs_ep0_queue_wait While performing fast composition switch, there is a possibility that the process of ffs_ep0_write/ffs_ep0_read get into a race condition due to ep0req being freed up from functionfs_unbind. Consider the scenario that the ffs_ep0_write calls the ffs_ep0_queue_wait by taking a lock &ffs->ev.waitq.lock. However, the functionfs_unbind isn't bounded so it can go ahead and mark the ep0req to NULL, and since there is no NULL check in ffs_ep0_queue_wait we will end up in use-after-free. Fix this by making a serialized execution between the two functions using a mutex_lock(ffs->mutex).

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2022-49755 since 03/27/2025. The exploitation appears to be difficult. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 12/06/2025).

Upgrading to version 4.14.305, 4.19.272, 5.4.231, 5.10.166, 5.15.91 or 6.1.9 eliminates this vulnerability. Applying the patch facf353c9e8d7885b686d9a4b173d4e0af6441d2/e9036e951f93fb8d7b5e9d6e2c7f94a4da312ae4/a8d40942df074f4ebcb9bd3413596d92f323b064/6dd9ea05534f323668db94fcc2726c7a84547e78/ae8e136bcaae96163b5821984de1036efc9abb1a/6aee197b7fbcd61596a78b47d553f2f99111f217/6a19da111057f69214b97c62fb0ac59023970850 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 CERT Bund (WID-SEC-2025-0649). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Dell Avamar
• Open Source Linux Kernel
• SolarWinds Security Event Manager
• Dell NetWorker
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.14.304
• 4.19.271
• 5.4.230
• 5.10.165
• 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
• 5.15.35
• 5.15.36
• 5.15.37
• 5.15.38
• 5.15.39
• 5.15.40
• 5.15.41
• 5.15.42
• 5.15.43
• 5.15.44
• 5.15.45
• 5.15.46
• 5.15.47
• 5.15.48
• 5.15.49
• 5.15.50
• 5.15.51
• 5.15.52
• 5.15.53
• 5.15.54
• 5.15.55
• 5.15.56
• 5.15.57
• 5.15.58
• 5.15.59
• 5.15.60
• 5.15.61
• 5.15.62
• 5.15.63
• 5.15.64
• 5.15.65
• 5.15.66
• 5.15.67
• 5.15.68
• 5.15.69
• 5.15.70
• 5.15.71
• 5.15.72
• 5.15.73
• 5.15.74
• 5.15.75
• 5.15.76
• 5.15.77
• 5.15.78
• 5.15.79
• 5.15.80
• 5.15.81
• 5.15.82
• 5.15.83
• 5.15.84
• 5.15.85
• 5.15.86
• 5.15.87
• 5.15.88
• 5.15.89
• 5.15.90
• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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