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| author | Michael S. Tsirkin <mst@redhat.com> | 2018-05-12 00:33:10 +0300 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2018-06-12 04:59:29 +0300 |
| commit | 670ae9caaca467ea1bfd325cb2a5c98ba87f94ad (patch) | |
| tree | fa217f1338634e7f9d0955193d66445cd78740a6 /drivers/vhost/vhost.c | |
| parent | 55e49dc43a835b19567e62142cb1c87dc7db7b3c (diff) | |
| download | linux-670ae9caaca467ea1bfd325cb2a5c98ba87f94ad.tar.gz linux-670ae9caaca467ea1bfd325cb2a5c98ba87f94ad.tar.bz2 linux-670ae9caaca467ea1bfd325cb2a5c98ba87f94ad.zip | |
vhost: fix info leak due to uninitialized memory
struct vhost_msg within struct vhost_msg_node is copied to userspace.
Unfortunately it turns out on 64 bit systems vhost_msg has padding after
type which gcc doesn't initialize, leaking 4 uninitialized bytes to
userspace.
This padding also unfortunately means 32 bit users of this interface are
broken on a 64 bit kernel which will need to be fixed separately.
Fixes: CVE-2018-1118
Cc: stable@vger.kernel.org
Reported-by: Kevin Easton <kevin@guarana.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reported-by: syzbot+87cfa083e727a224754b@syzkaller.appspotmail.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vhost/vhost.c')
| -rw-r--r-- | drivers/vhost/vhost.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index f0be5f35ab28..9beefa6ed1ce 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -2345,6 +2345,9 @@ struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type) struct vhost_msg_node *node = kmalloc(sizeof *node, GFP_KERNEL); if (!node) return NULL; + + /* Make sure all padding within the structure is initialized. */ + memset(&node->msg, 0, sizeof node->msg); node->vq = vq; node->msg.type = type; return node; |