Use-After-Free and Double Free in Linux Kernel SMB Client

Publication date: 2026-05-27

Last updated on: 2026-06-30

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential UAF and double free in smb2_open_file() Zero out @err_iov and @err_buftype before retrying SMB2_open() to prevent an UAF bug if @data != NULL, otherwise a double free.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-05-27

Last Modified

2026-06-30

Generated

2026-07-06

AI Q&A

2026-05-27

EPSS Evaluated

2026-07-05

NVD

CVE-2026-45972

EUVD

EUVD-2026-32256

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	6.19
linux	linux_kernel	From 6.12.70 (inc) to 6.12.75 (exc)
linux	linux_kernel	From 6.1.163 (inc) to 6.1.165 (exc)
linux	linux_kernel	From 6.18.10 (inc) to 6.18.14 (exc)
linux	linux_kernel	From 6.19.1 (inc) to 6.19.4 (exc)
linux	linux_kernel	From 6.6.124 (inc) to 6.6.128 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-825	The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.
CWE-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

Impact Analysis

Exploitation of this vulnerability could lead to memory corruption in the Linux kernel SMB client. This may result in system instability, crashes, or potentially allow an attacker to execute arbitrary code with kernel privileges, depending on the context and exploitability.

Executive Summary

This vulnerability exists in the Linux kernel's SMB client, specifically in the smb2_open_file() function. It involves a potential use-after-free (UAF) and double free issue. The problem occurs because certain variables (@err_iov and @err_buftype) were not properly zeroed out before retrying the SMB2_open() operation. If the @data pointer is not NULL, this can lead to a use-after-free bug; otherwise, it can cause a double free.

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