Buffer Overflow Vulnerability in Linux Kernel smb2_file_stream_info

CVE-2026-99273

What is CVE-2026-99273?

A vulnerability exists in the Linux kernel's handling of stream information in ksmbd, where the space reserved for a UTF-16 terminator is inadequate. Specifically, the function smb_strtoUTF16() writes a zero UTF-16 unit after converted characters, but the get_file_stream_info() function does not account for this in its memory allocation calculations. If the data perfectly fills the 448-byte small response buffer, the terminator is written past the allocated space, potentially resulting in a buffer overflow. This situation can compromise the integrity and security of the system, making it essential for users to apply patches that reserve the necessary space for the terminator.

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