Inconsistent Reference Count Update in Linux Kernel SMB Support

CVE-2025-39819

What is CVE-2025-39819?

A vulnerability was discovered in the Linux kernel's SMB support, specifically in the smb2_compound_op function. This issue involves an inconsistent update of the reference count for the cfile object, which can lead to potential resource leaks. The inconsistency arises due to a failure to properly handle the reference count in certain control flow paths, particularly when the function returns an error code of -ENOMEM, indicating memory allocation failure. A fix has been implemented to ensure that cleanup logic is executed correctly across all paths, thereby preventing resource mismanagement.

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