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authorWill Deacon <will.deacon@arm.com>2012-10-19 14:03:32 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-06-11 12:04:17 -0700
commit6330a0c429c1518714283be51b86dc02b45db882 (patch)
tree0741c1546b3580d3d7e519d568a3e47734a678ba
parentad988bcb5b18ad5e1865f638cfc7ba3e600c4d46 (diff)
downloadlinux-linaro-stable-6330a0c429c1518714283be51b86dc02b45db882.tar.gz
virtio: 9p: correctly pass physical address to userspace for high pages
commit 30d395b124c51db66d9f3ba0611cd62021afc392 upstream. commit b9cdc88df8e63e81c723b82c286fc97f5d0dc325 upstream. When using a virtio transport, the 9p net device may pass the physical address of a kernel buffer to userspace via a scatterlist inside a virtqueue. If the kernel buffer is mapped outside of the linear mapping (e.g. highmem), then virt_to_page will return a bogus value and we will populate the scatterlist with junk. This patch uses kmap_to_page when populating the page array for a kernel buffer. Cc: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/9p/trans_virtio.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 052d343d43ff..9f4fcc5419e5 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -39,6 +39,7 @@
#include <linux/inet.h>
#include <linux/idr.h>
#include <linux/file.h>
+#include <linux/highmem.h>
#include <linux/slab.h>
#include <net/9p/9p.h>
#include <linux/parser.h>
@@ -325,7 +326,7 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
int count = nr_pages;
while (nr_pages) {
s = rest_of_page(data);
- pages[index++] = virt_to_page(data);
+ pages[index++] = kmap_to_page(data);
data += s;
nr_pages--;
}