| From b9cdc88df8e63e81c723b82c286fc97f5d0dc325 Mon Sep 17 00:00:00 2001 |
| From: Will Deacon <will.deacon@arm.com> |
| Date: Fri, 19 Oct 2012 14:03:32 +0100 |
| Subject: virtio: 9p: correctly pass physical address to userspace for high pages |
| |
| From: Will Deacon <will.deacon@arm.com> |
| |
| 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. |
| |
| Signed-off-by: Will Deacon <will.deacon@arm.com> |
| Cc: Sasha Levin <levinsasha928@gmail.com> |
| Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| net/9p/trans_virtio.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| --- 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 vi |
| 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--; |
| } |