The iwd daemon uses libell which sets up the skcipher operation with two separate control messages. This is fine by itself but the first control message is sent without MSG_MORE. This means that the first control message is interpreted as an empty request.
While libell should be fixed to use MSG_MORE where appropriate, this patch works around the bug in the kernel so that existing binaries continue to work.
We will print a warning however.
Reported-by: Caleb Jorden caljorden@hotmail.com Fixes: f3c802a1f300 ("crypto: algif_aead - Only wake up when...") Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu herbert@gondor.apana.org.au
diff --git a/crypto/af_alg.c b/crypto/af_alg.c index a6f581ab200c..3da21cadc326 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -16,6 +16,7 @@ #include <linux/module.h> #include <linux/net.h> #include <linux/rwsem.h> +#include <linux/sched.h> #include <linux/sched/signal.h> #include <linux/security.h>
@@ -846,8 +847,14 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
lock_sock(sk); if (ctx->init && (init || !ctx->more)) { - err = -EINVAL; - goto unlock; + if (ctx->used) { + err = -EINVAL; + goto unlock; + } + + pr_info_once( + "%s sent an empty control message without MSG_MORE.\n", + current->comm); } ctx->init = true;