Linux Kernel up to 5.15.65/5.19.7 SMB2_negotiate buffer overflow

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.15.65/5.19.7. It has been rated as critical. Affected is the function SMB2_negotiate. This manipulation causes buffer overflow. The identification of this vulnerability is CVE-2022-49938. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 5.15.65/5.19.7. Affected by this vulnerability is the function SMB2_negotiate. The manipulation with an unknown input leads to a buffer overflow vulnerability. The CWE definition for the vulnerability is CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. 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: cifs: fix small mempool leak in SMB2_negotiate() In some cases of failure (dialect mismatches) in SMB2_negotiate(), after the request is sent, the checks would return -EIO when they should be rather setting rc = -EIO and jumping to neg_exit to free the response buffer from mempool.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2022-49938 since 05/01/2025. The exploitation appears to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/19/2025).

The vulnerability scanner Nessus provides a plugin with the ID 261434 (Amazon Linux 2 : kernel, --advisory ALAS2KERNEL-5.10-2025-103 (ALASKERNEL-5.10-2025-103)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.66 or 5.19.8 eliminates this vulnerability. Applying the patch 9e3c9efa7caf16e5acc05eab5e4d0a714e1610b0/38a6b469bf22f153282fbe7d702a24e9eb43f50e/27893dfc1285f80f80f46b3b8c95f5d15d2e66d0 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 databases at Tenable (261434), EUVD (EUVD-2022-55190) and CERT Bund (WID-SEC-2025-1350). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Dell Avamar
• Dell NetWorker
• Dell Secure Connect Gateway
• IBM QRadar SIEM

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 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
• 5.19.0
• 5.19.1
• 5.19.2
• 5.19.3
• 5.19.4
• 5.19.5
• 5.19.6
• 5.19.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

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