CVE-2025-68219
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-12-16

Last updated on: 2025-12-18

Assigner: kernel.org

Description
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
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Meta Information
Published
2025-12-16
Last Modified
2025-12-18
Generated
2026-06-16
AI Q&A
2025-12-16
EPSS Evaluated
2026-06-15
NVD
CVE-2025-68219
EUVD
EUVD-2025-203677
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
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Exploitability
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability is a memory leak in the Linux kernel's CIFS (Common Internet File System) implementation. Specifically, when processing SMB3 mount options, if an error occurs after certain memory allocations for source strings (ctx->source and fc->source), the old error handler fails to free this allocated memory, causing a leak. The fix involves properly freeing these source strings and setting pointers to NULL to prevent double-free issues.

Impact Analysis

The memory leak can lead to increased memory usage in the kernel over time, potentially degrading system performance or causing instability if the leak is significant or occurs frequently. This could affect systems using CIFS mounts with SMB3, especially under error conditions during mount option processing.

Mitigation Strategies

To mitigate this vulnerability, update your Linux kernel to a version that includes the fix for the memory leak in the cifs smb3_fs_context_parse_param error path. This fix ensures proper cleanup of allocated memory and prevents leaks. Until the update is applied, avoid using mount options that trigger the vulnerable code path if possible.

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