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Commit b9cdc88df8e63e81c723b82c286fc97f5d0dc325

Authored by Will Deacon
Committed by Rusty Russell
1 parent f0263d2d22
Exists in smarc-l5.0.0_1.0.0-ga and in 5 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga

virtio: 9p: correctly pass physical address to userspace for high pages 

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: stable@kernel.org
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Showing 1 changed file with 2 additions and 1 deletions Side-by-side Diff

net/9p/trans_virtio.c
Diff comments   View file @ b9cdc88
... ... @@ -39,6 +39,7 @@
39 39 #include <linux/inet.h>
40 40 #include <linux/idr.h>
41 41 #include <linux/file.h>
  42 +#include <linux/highmem.h>
42 43 #include <linux/slab.h>
43 44 #include <net/9p/9p.h>
44 45 #include <linux/parser.h>
... ... @@ -325,7 +326,7 @@
325 326 int count = nr_pages;
326 327 while (nr_pages) {
327 328 s = rest_of_page(data);
328   - pages[index++] = virt_to_page(data);
  329 + pages[index++] = kmap_to_page(data);
329 330 data += s;
330 331 nr_pages--;
331 332 }