[PATCH 6.6 49/50] rxrpc: Fix missing error checks for rxkad encryption/decryption failure

Greg Kroah-Hartman
2026-04-13T16:15:34Z

From: David Howells <dhowells@redhat.com>

commit f93af41b9f5f798823d0d0fb8765c2a936d76270 upstream.

Add error checking for failure of crypto_skcipher_en/decrypt() to various
rxkad function as the crypto functions can fail with ENOMEM at least.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Closes: https://sashiko.dev/#/patchset/20260401105614.1696001-10-dhowells@redhat.com
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jeffrey Altman <jaltman@auristor.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: stable@kernel.org
Link: https://patch.msgid.link/20260408121252.2249051-17-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/rxrpc/rxkad.c | 57 ++++++++++++++++++++++++++++++++++++------------------
1 file changed, 38 insertions(+), 19 deletions(-)

--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -189,6 +189,7 @@ static int rxkad_prime_packet_security(s
struct rxrpc_crypt iv;
__be32 *tmpbuf;
size_t tmpsize = 4 * sizeof(__be32);
+ int ret;

_enter("");

@@ -217,13 +218,13 @@ static int rxkad_prime_packet_security(s
skcipher_request_set_sync_tfm(req, ci);
skcipher_request_set_callback(req, 0, NULL, NULL);
skcipher_request_set_crypt(req, &sg, &sg, tmpsize, iv.x);
- crypto_skcipher_encrypt(req);
+ ret = crypto_skcipher_encrypt(req);
skcipher_request_free(req);

memcpy(&conn->rxkad.csum_iv, tmpbuf + 2, sizeof(conn->rxkad.csum_iv));
kfree(tmpbuf);
- _leave(" = 0");
- return 0;
+ _leave(" = %d", ret);
+ return ret;
}

/*
@@ -256,6 +257,7 @@ static int rxkad_secure_packet_auth(cons
struct scatterlist sg;
size_t pad;
u16 check;
+ int ret;

_enter("");

@@ -278,11 +280,11 @@ static int rxkad_secure_packet_auth(cons
skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher);
skcipher_request_set_callback(req, 0, NULL, NULL);
skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
- crypto_skcipher_encrypt(req);
+ ret = crypto_skcipher_encrypt(req);
skcipher_request_zero(req);

- _leave(" = 0");
- return 0;
+ _leave(" = %d", ret);
+ return ret;
}

/*
@@ -340,7 +342,7 @@ static int rxkad_secure_packet(struct rx
union {
__be32 buf[2];
} crypto __aligned(8);
- u32 x, y;
+ u32 x, y = 0;
int ret;

_enter("{%d{%x}},{#%u},%u,",
@@ -371,8 +373,10 @@ static int rxkad_secure_packet(struct rx
skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher);
skcipher_request_set_callback(req, 0, NULL, NULL);
skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
- crypto_skcipher_encrypt(req);
+ ret = crypto_skcipher_encrypt(req);
skcipher_request_zero(req);
+ if (ret < 0)
+ goto out;

y = ntohl(crypto.buf[1]);
y = (y >> 16) & 0xffff;
@@ -395,6 +399,7 @@ static int rxkad_secure_packet(struct rx
break;
}

+out:
skcipher_request_free(req);
_leave(" = %d [set %x]", ret, y);
return ret;
@@ -435,8 +440,10 @@ static int rxkad_verify_packet_1(struct
skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher);
skcipher_request_set_callback(req, 0, NULL, NULL);
skcipher_request_set_crypt(req, sg, sg, 8, iv.x);
- crypto_skcipher_decrypt(req);
+ ret = crypto_skcipher_decrypt(req);
skcipher_request_zero(req);
+ if (ret < 0)
+ return ret;

/* Extract the decrypted packet length */
if (skb_copy_bits(skb, sp->offset, &sechdr, sizeof(sechdr)) < 0)
@@ -513,10 +520,14 @@ static int rxkad_verify_packet_2(struct
skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher);
skcipher_request_set_callback(req, 0, NULL, NULL);
skcipher_request_set_crypt(req, sg, sg, sp->len, iv.x);
- crypto_skcipher_decrypt(req);
+ ret = crypto_skcipher_decrypt(req);
skcipher_request_zero(req);
if (sg != _sg)
kfree(sg);
+ if (ret < 0) {
+ WARN_ON_ONCE(ret != -ENOMEM);
+ return ret;
+ }

/* Extract the decrypted packet length */
if (skb_copy_bits(skb, sp->offset, &sechdr, sizeof(sechdr)) < 0)
@@ -584,8 +595,10 @@ static int rxkad_verify_packet(struct rx
skcipher_request_set_sync_tfm(req, call->conn->rxkad.cipher);
skcipher_request_set_callback(req, 0, NULL, NULL);
skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
- crypto_skcipher_encrypt(req);
+ ret = crypto_skcipher_encrypt(req);
skcipher_request_zero(req);
+ if (ret < 0)
+ goto out;

y = ntohl(crypto.buf[1]);
cksum = (y >> 16) & 0xffff;
@@ -988,21 +1001,23 @@ static int rxkad_decrypt_ticket(struct r
/*
* decrypt the response packet
*/
-static void rxkad_decrypt_response(struct rxrpc_connection *conn,
- struct rxkad_response *resp,
- const struct rxrpc_crypt *session_key)
+static int rxkad_decrypt_response(struct rxrpc_connection *conn,
+ struct rxkad_response *resp,
+ const struct rxrpc_crypt *session_key)
{
struct skcipher_request *req = rxkad_ci_req;
struct scatterlist sg[1];
struct rxrpc_crypt iv;
+ int ret;

_enter(",,%08x%08x",
ntohl(session_key->n[0]), ntohl(session_key->n[1]));

mutex_lock(&rxkad_ci_mutex);
- if (crypto_sync_skcipher_setkey(rxkad_ci, session_key->x,
- sizeof(*session_key)) < 0)
- BUG();
+ ret = crypto_sync_skcipher_setkey(rxkad_ci, session_key->x,
+ sizeof(*session_key));
+ if (ret < 0)
+ goto unlock;

memcpy(&iv, session_key, sizeof(iv));

@@ -1011,12 +1026,14 @@ static void rxkad_decrypt_response(struc
skcipher_request_set_sync_tfm(req, rxkad_ci);
skcipher_request_set_callback(req, 0, NULL, NULL);
skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
- crypto_skcipher_decrypt(req);
+ ret = crypto_skcipher_decrypt(req);
skcipher_request_zero(req);

+unlock:
mutex_unlock(&rxkad_ci_mutex);

_leave("");
+ return ret;
}

/*
@@ -1109,7 +1126,9 @@ static int rxkad_verify_response(struct

/* use the session key from inside the ticket to decrypt the
* response */
- rxkad_decrypt_response(conn, response, &session_key);
+ ret = rxkad_decrypt_response(conn, response, &session_key);
+ if (ret < 0)
+ goto temporary_error_free_ticket;

if (ntohl(response->encrypted.epoch) != conn->proto.epoch ||
ntohl(response->encrypted.cid) != conn->proto.cid ||