From 349271568303695f0ac3563af153d2b4542f6986 Mon Sep 17 00:00:00 2001 From: KP Singh Date: Sun, 21 Sep 2025 18:01:16 +0200 Subject: bpf: Implement signature verification for BPF programs This patch extends the BPF_PROG_LOAD command by adding three new fields to `union bpf_attr` in the user-space API: - signature: A pointer to the signature blob. - signature_size: The size of the signature blob. - keyring_id: The serial number of a loaded kernel keyring (e.g., the user or session keyring) containing the trusted public keys. When a BPF program is loaded with a signature, the kernel: 1. Retrieves the trusted keyring using the provided `keyring_id`. 2. Verifies the supplied signature against the BPF program's instruction buffer. 3. If the signature is valid and was generated by a key in the trusted keyring, the program load proceeds. 4. If no signature is provided, the load proceeds as before, allowing for backward compatibility. LSMs can chose to restrict unsigned programs and implement a security policy. 5. If signature verification fails for any reason, the program is not loaded. Tested-by: syzbot@syzkaller.appspotmail.com Signed-off-by: KP Singh Link: https://lore.kernel.org/r/20250921160120.9711-2-kpsingh@kernel.org Signed-off-by: Alexei Starovoitov --- include/linux/verification.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/verification.h b/include/linux/verification.h index 4f3022d081c3..dec7f2beabfd 100644 --- a/include/linux/verification.h +++ b/include/linux/verification.h @@ -36,6 +36,7 @@ enum key_being_used_for { VERIFYING_KEY_SIGNATURE, VERIFYING_KEY_SELF_SIGNATURE, VERIFYING_UNSPECIFIED_SIGNATURE, + VERIFYING_BPF_SIGNATURE, NR__KEY_BEING_USED_FOR }; #ifdef CONFIG_SYSTEM_DATA_VERIFICATION -- cgit v1.2.3