git: a0cbcbb7917b - main - cryptodev: Allow some CIOCCRYPT operations with an empty payload.

The branch main has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=a0cbcbb7917b0b8566ec0853425a73d7958ddbed

commit a0cbcbb7917b0b8566ec0853425a73d7958ddbed
Author:     John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2021-10-06 21:08:47 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2021-10-06 21:08:47 +0000

    cryptodev: Allow some CIOCCRYPT operations with an empty payload.
    
    If an operation would generate a MAC output (e.g. for digest operation
    or for an AEAD or EtA operation), then an empty payload buffer is
    valid.  Only reject requests with an empty buffer for "plain" cipher
    sessions.
    
    Some of the AES-CCM NIST KAT vectors use an empty payload.
    
    While here, don't advance crp_payload_start for requests that use an
    empty payload with an inline IV. (*)
    
    Reported by:    syzbot+d4b94fbd9a44b032f428@syzkaller.appspotmail.com (*)
    Reviewed by:    markj
    Sponsored by:   The FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D32109
---
 sys/opencrypto/cryptodev.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/sys/opencrypto/cryptodev.c b/sys/opencrypto/cryptodev.c
index 3224ed3f900c..9312945a9b8b 100644
--- a/sys/opencrypto/cryptodev.c
+++ b/sys/opencrypto/cryptodev.c
@@ -781,7 +781,7 @@ cryptodev_op(struct csession *cse, const struct crypt_op *cop)
 	}
 
 	if (cse->txform) {
-		if (cop->len == 0 || (cop->len % cse->txform->blocksize) != 0) {
+		if ((cop->len % cse->txform->blocksize) != 0) {
 			SDT_PROBE1(opencrypto, dev, ioctl, error, __LINE__);
 			return (EINVAL);
 		}
@@ -836,6 +836,12 @@ cryptodev_op(struct csession *cse, const struct crypt_op *cop)
 		}
 		break;
 	case CSP_MODE_CIPHER:
+		if (cop->len == 0 ||
+		    (cop->iv == NULL && cop->len == cse->ivsize)) {
+			SDT_PROBE1(opencrypto, dev, ioctl, error, __LINE__);
+			error = EINVAL;
+			goto bail;
+		}
 		switch (cop->op) {
 		case COP_ENCRYPT:
 			crp->crp_op = CRYPTO_OP_ENCRYPT;
@@ -919,8 +925,9 @@ cryptodev_op(struct csession *cse, const struct crypt_op *cop)
 			goto bail;
 		}
 		crp->crp_iv_start = 0;
-		crp->crp_payload_start += cse->ivsize;
 		crp->crp_payload_length -= cse->ivsize;
+		if (crp->crp_payload_length != 0)
+			crp->crp_payload_start = cse->ivsize;
 		dst += cse->ivsize;
 	}