---
id: CVE-2025-68219
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  cifs: fix memory leak in smb3_fs_context_parse_param error path

  Add proper cleanup of ctx->source and fc->source to the
  cifs_parse_mount_err error handler
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  cifs: fix memory leak in smb3_fs_context_parse_param error path

  Add proper cleanup of ctx->source and fc->source to the
  cifs_parse_mount_err error handler. This ensure…
severity: none
published: '2025-12-16'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T13:10:00.187'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-68219'
references:
  - url: 'https://git.kernel.org/stable/c/37010021d7e0341bb241ca00bcbae31f2c50b23f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/48d69290270891f988e72edddd9688c20515421d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7627864dc3121f39e220f5253a227edf472de59e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7e4d9120cfa413dd34f4f434befc5dbe6c38b2e5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00199
epssPercentile: 0.09063
ingestedAt: '2026-10-14T13:30:58.458Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

cifs: fix memory leak in smb3_fs_context_parse_param error path

Add proper cleanup of ctx->source and fc->source to the
cifs_parse_mount_err error handler. This ensures that memory allocated
for the source strings is correctly freed on all error paths, matching
the cleanup already performed in the success path by
smb3_cleanup_fs_context_contents().
Pointers are also set to NULL after freeing to prevent potential
double-free issues.

This change fixes a memory leak originally detected by syzbot. The
leak occurred when processing Opt_source mount options if an error
happened after ctx->source and fc->source were successfully
allocated but before the function completed.

The specific leak sequence was:
1. ctx->source = smb3_fs_context_fullpath(ctx, '/') allocates memory
2. fc->source = kstrdup(ctx->source, GFP_KERNEL) allocates more memory
3. A subsequent error jumps to cifs_parse_mount_err
4. The old error handler freed passwords but not the source strings,
causing the memory to leak.

This issue was not addressed by commit e8c73eb7db0a ("cifs: client:
fix memory leak in smb3_fs_context_parse_param"), which only fixed
leaks from repeated fsconfig() calls but not this error path.

Patch updated with minor change suggested by kernel test robot

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.