From: Eric Biggers <ebiggers@xxxxxxxxxx> It isn't clearly defined what happens if you read from an AF_ALG request socket without previously sending the control data to begin an encryption or decryption operation. On some kernels the read will return 0, while on others it will block. Testing this corner case isn't the purpose of af_alg02; it just wants to try to encrypt a zero-length message. So, change it to explicitly send a zero-length message with control data. This fixes the test failure reported at https://lkml.kernel.org/r/CA+G9fYtebf78TH-XpqArunHc1L6s9mHdLEbpY1EY9tSyDjp=sg@xxxxxxxxxxxxxx Fixing the test in this way was also previously suggested at https://lkml.kernel.org/r/20200702033221.GA19367@xxxxxxxxxxxxxxxxxxx Note, this patch doesn't change the fact that the read() still blocks on pre-4.14 kernels (which is a kernel bug), and thus the timeout logic in the test is still needed. Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> --- testcases/kernel/crypto/af_alg02.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/testcases/kernel/crypto/af_alg02.c b/testcases/kernel/crypto/af_alg02.c index fab0010c9..31d30777c 100644 --- a/testcases/kernel/crypto/af_alg02.c +++ b/testcases/kernel/crypto/af_alg02.c @@ -21,14 +21,29 @@ #include <pthread.h> #include <errno.h> +#define SALSA20_IV_SIZE 8 +#define SALSA20_MIN_KEY_SIZE 16 + static void *verify_encrypt(void *arg) { + const uint8_t iv[SALSA20_IV_SIZE] = { 0 }; + const struct tst_alg_sendmsg_params params = { + .encrypt = true, + .iv = iv, + .ivlen = SALSA20_IV_SIZE, + }; char buf[16]; - int reqfd = tst_alg_setup_reqfd("skcipher", "salsa20", NULL, 16); + int reqfd = tst_alg_setup_reqfd("skcipher", "salsa20", NULL, + SALSA20_MIN_KEY_SIZE); - TST_CHECKPOINT_WAKE(0); + /* Send a zero-length message to encrypt */ + tst_alg_sendmsg(reqfd, NULL, 0, ¶ms); - /* With the bug the kernel crashed here */ + /* + * Read the zero-length encrypted data. + * With the bug, the kernel crashed here. + */ + TST_CHECKPOINT_WAKE(0); if (read(reqfd, buf, 16) == 0) tst_res(TPASS, "Successfully \"encrypted\" an empty message"); else -- 2.28.0
