[PATCH 4.19 135/168] net/tls: Fix kmap usage

Greg Kroah-Hartman
2020-08-17T17:35:28Z

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

[ Upstream commit b06c19d9f827f6743122795570bfc0c72db482b0 ]

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.

Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/tls/tls_device.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -476,7 +476,7 @@ int tls_device_sendpage(struct sock *sk,
int offset, size_t size, int flags)
{
struct iov_iter msg_iter;
- char *kaddr = kmap(page);
+ char *kaddr;
struct kvec iov;
int rc;

@@ -490,6 +490,7 @@ int tls_device_sendpage(struct sock *sk,
goto out;
}

+ kaddr = kmap(page);
iov.iov_base = kaddr + offset;
iov.iov_len = size;
iov_iter_kvec(&msg_iter, WRITE | ITER_KVEC, &iov, 1, size);