lib/crypto: chacha: Add at_least decoration to fixed-size array params

Add the at_least (i.e. 'static') decoration to the fixed-size array
parameters of the chacha library functions.  This causes clang to warn
when a too-small array of known size is passed.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20251122194206.31822-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

diff --git a/include/crypto/chacha.h b/include/crypto/chacha.h
index 38e26dff27b00a80df029b1e620b73d4ad0b95f2..1cc301a48469751f1d6d2e59d4cd7e2169fa22f5 100644 (file)
--- a/include/crypto/chacha.h
+++ b/include/crypto/chacha.h
@@ -38,18 +38,18 @@ struct chacha_state {
 };
 
 void chacha_block_generic(struct chacha_state *state,
-                         u8 out[CHACHA_BLOCK_SIZE], int nrounds);
+                         u8 out[at_least CHACHA_BLOCK_SIZE], int nrounds);
 static inline void chacha20_block(struct chacha_state *state,
-                                 u8 out[CHACHA_BLOCK_SIZE])
+                                 u8 out[at_least CHACHA_BLOCK_SIZE])
 {
        chacha_block_generic(state, out, 20);
 }
 
 void hchacha_block_generic(const struct chacha_state *state,
-                          u32 out[HCHACHA_OUT_WORDS], int nrounds);
+                          u32 out[at_least HCHACHA_OUT_WORDS], int nrounds);
 
 void hchacha_block(const struct chacha_state *state,
-                  u32 out[HCHACHA_OUT_WORDS], int nrounds);
+                  u32 out[at_least HCHACHA_OUT_WORDS], int nrounds);
 
 enum chacha_constants { /* expand 32-byte k */
        CHACHA_CONSTANT_EXPA = 0x61707865U,
@@ -67,8 +67,8 @@ static inline void chacha_init_consts(struct chacha_state *state)
 }
 
 static inline void chacha_init(struct chacha_state *state,
-                              const u32 key[CHACHA_KEY_WORDS],
-                              const u8 iv[CHACHA_IV_SIZE])
+                              const u32 key[at_least CHACHA_KEY_WORDS],
+                              const u8 iv[at_least CHACHA_IV_SIZE])
 {
        chacha_init_consts(state);
        state->x[4]  = key[0];