On Thu, 27 Aug 2020 at 09:15, Herbert Xu herbert@gondor.apana.org.au wrote:
On Thu, Aug 27, 2020 at 08:40:01AM +0200, Ard Biesheuvel wrote:
It is part of iwd - just build that and run 'make check'
With your patch applied, the occurrence of sendmsg() in operate_cipher() triggers the warn_once(), but if I add MSG_MORE there, the test hangs.
I see. This is a different issue. The original kernel change was a bit too strict here and it is barfing at the fact that two successive sendmsg's of the same request both contain a control message.
Here's an updated patch to allow this.
---8<--- The iwd daemon uses libell which sets up the skcipher operation with two separate control messages. As the first control message is sent without MSG_MORE, it 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.
A separate issue is that the new kernel code no longer allows the control message to be sent twice within the same request. This restriction is obviously incompatible with what iwd was doing (first setting an IV and then sending the real control message). This patch changes the kernel so that this is explicitly allowed.
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..8be8bec07cdd 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>
@@ -845,9 +846,15 @@ 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->init && !ctx->more) {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;
Yep, that works.