fsverity_verify_signature(9)

💖 fsverity_verify_signature(9) — check a verity file's signature ✨

okay so bestie, welcome to the Kernel API Manual page for fsverity_verify_signature(9). This is the signature-verifying main character of fs-verity, and we're gonna get into it. No cap. 🫶

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✨ NAME ✨

fsverity_verify_signature — check a verity file's signature 💅

🎀 SYNOPSIS 🎀

int fsverity_verify_signature (const struct fsverity_info *vi , const u8
       *signature , size_t sig_size );

💅 ARGUMENTS 💅

• vi — the file's fsverity_info. It's the file's little info badge, iykyk. 🪪
• signature — the file's built-in signature. 🔏
• sig_size — size of signature in bytes, or 0 if no signature. 📏

🔥 DESCRIPTION 🔥

So here's the tea: if the file includes a signature of its fs-verity file digest, this function verifies it against the certificates in the fs-verity keyring. That's the whole assignment. 🔑

And note — signatures are verified regardless of the state of the 'fsverity_require_signatures' variable, and the LSM subsystem relies on this behavior to help enforce file integrity policies. This is highkey important, so don't mess with it casually. 🛡️

Please discuss changes with the LSM list (thank you!). Fr fr, talk to the LSM girlies first. 💌

🌈 RETURN 🌈

• 0 on success (signature valid or not required); -errno on failure. ✅😭

🦋 SEE ALSO 🦋

• Kernel file ./fs/verity/signature.c — go read the source, bestie. 📖

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Signed off with 💖 from the ./fs/verity source/version and the October 2026 date — fsverity_verify_signature(9), periodt. 🎀