lib/crypto/poly1305: Fix arm64's poly1305_blocks_arch()

For some reason arm64's Poly1305 code got changed to ignore the padbit
argument.  As a result, the output is incorrect when the message length
is not a multiple of 16 (which is not reached with the standard
ChaCha20Poly1305, but bcachefs could reach this).  Fix this.

Fixes: a59e5468a921 ("crypto: arm64/poly1305 - Add block-only interface")
Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Tested-by: Kent Overstreet <kent.overstreet@linux.dev>
Link: https://lore.kernel.org/r/20250616010654.367302-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

diff --git a/arch/arm64/lib/crypto/poly1305-glue.c b/arch/arm64/lib/crypto/poly1305-glue.c
index 6a661cf048213a053ccd51aa1a2018275068fb48..c9a74766785bd7b4412640f1b7e996f9ff3df6db 100644 (file)
--- a/arch/arm64/lib/crypto/poly1305-glue.c
+++ b/arch/arm64/lib/crypto/poly1305-glue.c
@@ -38,14 +38,14 @@ void poly1305_blocks_arch(struct poly1305_block_state *state, const u8 *src,
                        unsigned int todo = min_t(unsigned int, len, SZ_4K);
 
                        kernel_neon_begin();
-                       poly1305_blocks_neon(state, src, todo, 1);
+                       poly1305_blocks_neon(state, src, todo, padbit);
                        kernel_neon_end();
 
                        len -= todo;
                        src += todo;
                } while (len);
        } else
-               poly1305_blocks(state, src, len, 1);
+               poly1305_blocks(state, src, len, padbit);
 }
 EXPORT_SYMBOL_GPL(poly1305_blocks_arch);