[PATCH] net/tls: Fix kmap usage

[ira . weiny]

From: Ira Weiny <ira.we...@intel.com>

When MSG_OOB is specified to tls_device_sendpage() the mapped page is
never unmapped.

Hold off mapping the page until after the flags are checked and the page
is actually needed.

Signed-off-by: Ira Weiny <ira.we...@intel.com>
---
 net/tls/tls_device.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 0e55f8365ce2..0cbad566f281 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -561,7 +561,7 @@ int tls_device_sendpage(struct sock *sk, struct page *page,
 {
        struct tls_context *tls_ctx = tls_get_ctx(sk);
        struct iov_iter msg_iter;
-       char *kaddr = kmap(page);
+       char *kaddr;
        struct kvec iov;
        int rc;
 
@@ -576,6 +576,7 @@ int tls_device_sendpage(struct sock *sk, struct page *page,
                goto out;
        }
 
+       kaddr = kmap(page);
        iov.iov_base = kaddr + offset;
        iov.iov_len = size;
        iov_iter_kvec(&msg_iter, WRITE, &iov, 1, size);
-- 
2.28.0.rc0.12.gb6a658bd00c9