drivers: avoid parsing names as kthread_run() format strings

Calling kthread_run with a single name parameter causes it to be handled
as a format string. Many callers are passing potentially dynamic string
content, so use "%s" in those cases to avoid any potential accidents.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 4 insertions, 3 deletions

diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index fc803ecbbce4..b75c7db16559 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -1340,7 +1340,7 @@ aoe_ktstart(struct ktstate *k)
         struct task_struct *task;
 
         init_completion(&k->rendez);
-        task = kthread_run(kthread, k, k->name);
+        task = kthread_run(kthread, k, "%s", k->name);
         if (task == NULL || IS_ERR(task))
                 return -ENOMEM;
         k->task = task;
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 20dd52a2f92f..952dbfe22126 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -4087,7 +4087,8 @@ skip_create_disk:
 start_service_thread:
         sprintf(thd_name, "mtip_svc_thd_%02d", index);
         dd->mtip_svc_handler = kthread_create_on_node(mtip_service_thread,
-                                                dd, dd->numa_node, thd_name);
+                                                dd, dd->numa_node, "%s",
+                                                thd_name);
 
         if (IS_ERR(dd->mtip_svc_handler)) {
                 dev_err(&dd->pdev->dev, "service thread failed to start\n");
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 8bfd1bcf95ec..04608a6502d7 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -93,7 +93,7 @@ static void xen_update_blkif_status(struct xen_blkif *blkif)
         }
         invalidate_inode_pages2(blkif->vbd.bdev->bd_inode->i_mapping);
 
-        blkif->xenblkd = kthread_run(xen_blkif_schedule, blkif, name);
+        blkif->xenblkd = kthread_run(xen_blkif_schedule, blkif, "%s", name);
         if (IS_ERR(blkif->xenblkd)) {
                 err = PTR_ERR(blkif->xenblkd);
                 blkif->xenblkd = NULL;