From: Wu Bo <wubo40@xxxxxxxxxx>
If cache_alloc() get error when register a cache device,
the ca->kobj is not initialized, the bch_cache_release() no chance
to be called. So "ca" object will not be released.
In addition, if register_cache_set() return failed
when register a cache device, kobject_put(&ca->kobj) will be called
and "ca" objects will be released in bch_cache_release() function.
But pr_notice() called after kobject_put(&ca->kobj),
the "ca->cache_dev_name" access memory that has been freed.
Signed-off-by: Wu Bo <wubo40@xxxxxxxxxx>
---
drivers/md/bcache/super.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index f2874c7..30569f4 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -2366,13 +2366,17 @@ static int register_cache(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
* explicitly call blkdev_put() here.
*/
blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
+ if (ca->sb_disk)
+ put_page(virt_to_page(ca->sb_disk));
if (ret == -ENOMEM)
err = "cache_alloc(): -ENOMEM";
else if (ret == -EPERM)
err = "cache_alloc(): cache device is too small";
else
err = "cache_alloc(): unknown error";
- goto err;
+ pr_notice("error %s: %s\n", ca->cache_dev_name, err);
+ kfree(ca);
+ return ret;
}
if (kobject_add(&ca->kobj, bdev_kobj(bdev), "bcache")) {
@@ -2393,11 +2397,9 @@ static int register_cache(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
pr_info("registered cache device %s\n", ca->cache_dev_name);
out:
- kobject_put(&ca->kobj);
-
-err:
if (err)
pr_notice("error %s: %s\n", ca->cache_dev_name, err);
+ kobject_put(&ca->kobj);
return ret;
}
--
1.8.3.1
