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authorRoger Pau Monne <roger.pau@citrix.com>2022-03-30 09:03:48 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-07-07 17:31:18 +0200
commit44dc5bcac4b0ec4e876110a69ead25a9b130234b (patch)
tree6684e6aeb7c6babbcf4e7923520faadb6b3f412a
parent57e7b02611e3618d7e1b3a57270924af029ede8e (diff)
xen/blkfront: fix leaking data in shared pages
commit 2f446ffe9d737e9a844b97887919c4fda18246e7 upstream. When allocating pages to be used for shared communication with the backend always zero them, this avoids leaking unintended data present on the pages. This is CVE-2022-26365, part of XSA-403. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/block/xen-blkfront.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index a97a306c3850..c9b2e3bea30c 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -302,7 +302,7 @@ static int fill_grant_buffer(struct blkfront_ring_info *rinfo, int num)
goto out_of_memory;
if (info->feature_persistent) {
- granted_page = alloc_page(GFP_NOIO);
+ granted_page = alloc_page(GFP_NOIO | __GFP_ZERO);
if (!granted_page) {
kfree(gnt_list_entry);
goto out_of_memory;
@@ -1744,7 +1744,7 @@ static int setup_blkring(struct xenbus_device *dev,
for (i = 0; i < info->nr_ring_pages; i++)
rinfo->ring_ref[i] = GRANT_INVALID_REF;
- sring = alloc_pages_exact(ring_size, GFP_NOIO);
+ sring = alloc_pages_exact(ring_size, GFP_NOIO | __GFP_ZERO);
if (!sring) {
xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring");
return -ENOMEM;
@@ -2266,7 +2266,8 @@ static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo)
BUG_ON(!list_empty(&rinfo->indirect_pages));
for (i = 0; i < num; i++) {
- struct page *indirect_page = alloc_page(GFP_NOIO);
+ struct page *indirect_page = alloc_page(GFP_NOIO |
+ __GFP_ZERO);
if (!indirect_page)
goto out_of_memory;
list_add(&indirect_page->lru, &rinfo->indirect_pages);