From 65a10e28aee72903a41670170cd5330ad73c490e Mon Sep 17 00:00:00 2001 From: Vakul Garg Date: Fri, 21 Dec 2018 15:16:52 +0000 Subject: [PATCH] tls: Do not call sk_memcopy_from_iter with zero length In some conditions e.g. when tls_clone_plaintext_msg() returns -ENOSPC, the number of bytes to be copied using subsequent function sk_msg_memcopy_from_iter() becomes zero. This causes function sk_msg_memcopy_from_iter() to fail which in turn causes tls_sw_sendmsg() to return failure. To prevent it, do not call sk_msg_memcopy_from_iter() when number of bytes to copy (indicated by 'try_to_copy') is zero. Fixes: d829e9c4112b ("tls: convert to generic sk_msg interface") Signed-off-by: Vakul Garg Signed-off-by: David S. Miller --- net/tls/tls_sw.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 7b1af8b59cd2..29b27858fff1 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -935,10 +935,12 @@ fallback_to_reg_send: tls_ctx->tx.overhead_size); } - ret = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, msg_pl, - try_to_copy); - if (ret < 0) - goto trim_sgl; + if (try_to_copy) { + ret = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, + msg_pl, try_to_copy); + if (ret < 0) + goto trim_sgl; + } /* Open records defined only if successfully copied, otherwise * we would trim the sg but not reset the open record frags.