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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 17:36:52 +0200
commit42112e8f94617d83943f8f3b8de2b66041905506 (patch)
tree4db733970f6e76419b612b9d793538cae0b736af
parentb7c996abe545d69d2ee73a190a9dfe037948cbd5 (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 3731066f2c1c..b8e0a49dabb6 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -301,7 +301,7 @@ 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;
@@ -2283,7 +2283,8 @@ 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_KERNEL);
+ struct page *indirect_page = alloc_page(GFP_KERNEL |
+ __GFP_ZERO);
if (!indirect_page)
goto out_of_memory;
list_add(&indirect_page->lru, &rinfo->indirect_pages);