From: Kees Cook <keescook@chromium.org>
Subject: pstore/platform: Switch pstore_info::name to const
Git-commit: 563ca40ddf400dbf8c6254077f9b6887101d0f08
Patch-mainline: v5.8
References: jsc#SLE-16304
Acked-by: Jiri Bohac <jbohac@suse.cz>

In order to more cleanly pass around backend names, make the "name" member
const. This means the module param needs to be dynamic (technically, it
was before, so this actually cleans up a minor memory leak if a backend
was specified and then gets unloaded.)

Link: https://lore.kernel.org/lkml/20200510202436.63222-3-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 8beaeff72386..715396bef0ea 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -624,7 +624,7 @@ int pstore_register(struct pstore_info *psi)
 	 * Update the module parameter backend, so it is visible
 	 * through /sys/module/pstore/parameters/backend
 	 */
-	backend = psi->name;
+	backend = kstrdup(psi->name, GFP_KERNEL);
 
 	pr_info("Registered %s as persistent store backend\n", psi->name);
 
@@ -667,6 +667,7 @@ void pstore_unregister(struct pstore_info *psi)
 	free_buf_for_compression();
 
 	psinfo = NULL;
+	kfree(backend);
 	backend = NULL;
 	mutex_unlock(&psinfo_lock);
 }
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index e779441e6d26..f6f22b13e04f 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -170,7 +170,7 @@ struct pstore_record {
  */
 struct pstore_info {
 	struct module	*owner;
-	char		*name;
+	const char	*name;
 
 	struct semaphore buf_lock;
 	char		*buf;
-- 
2.28.0