CVE-2025-68219: Linux kernel · cifs: fix memory leak in smb3_fs_context_parse_param error path
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in a8071fd69df335362be5ecf5df5a167fd1eb5853 : update Linux kernel when convenient.
Data as of 30 Oct 2026, 12:49 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- Patch
- Available – fixed in a8071fd69df335362be5ecf5df5a167fd1eb5853, 37010021d7e0341bb241ca00bcbae31f2c50b23f, 7627864dc3121f39e220f5253a227edf472de59e +2
Exploitation evidence
Disclosed: evidence found.
CVE published 16 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
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
References
- git.kernel.org/stable/c/a8071fd69df335362be5ecf5df5a167fd1eb5853 (opens in a new tab)
- git.kernel.org/stable/c/7627864dc3121f39e220f5253a227edf472de59e (opens in a new tab)
- git.kernel.org/stable/c/48d69290270891f988e72edddd9688c20515421d (opens in a new tab)
- git.kernel.org/stable/c/37010021d7e0341bb241ca00bcbae31f2c50b23f (opens in a new tab)
- git.kernel.org/stable/c/7e4d9120cfa413dd34f4f434befc5dbe6c38b2e5 (opens in a new tab)