From: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Date: Fri, 23 Jun 2023 02:27:06 +0000 (+0800)
Subject: pstore/platform: Add check for kstrdup
X-Git-Tag: v6.5.12~521
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1c426da79f9fc7b761021b5eb44185ba119cd44a;p=thirdparty%2Fkernel%2Fstable.git

pstore/platform: Add check for kstrdup

[ Upstream commit a19d48f7c5d57c0f0405a7d4334d1d38fe9d3c1c ]

Add check for the return value of kstrdup() and return the error
if it fails in order to avoid NULL pointer dereference.

Fixes: 563ca40ddf40 ("pstore/platform: Switch pstore_info::name to const")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/20230623022706.32125-1-jiasheng@iscas.ac.cn
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index cbc0b468c1ab6..15cefe268ffd8 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -573,6 +573,8 @@ out:
  */
 int pstore_register(struct pstore_info *psi)
 {
+	char *new_backend;
+
 	if (backend && strcmp(backend, psi->name)) {
 		pr_warn("backend '%s' already in use: ignoring '%s'\n",
 			backend, psi->name);
@@ -593,11 +595,16 @@ int pstore_register(struct pstore_info *psi)
 		return -EINVAL;
 	}
 
+	new_backend = kstrdup(psi->name, GFP_KERNEL);
+	if (!new_backend)
+		return -ENOMEM;
+
 	mutex_lock(&psinfo_lock);
 	if (psinfo) {
 		pr_warn("backend '%s' already loaded: ignoring '%s'\n",
 			psinfo->name, psi->name);
 		mutex_unlock(&psinfo_lock);
+		kfree(new_backend);
 		return -EBUSY;
 	}
 
@@ -630,7 +637,7 @@ int pstore_register(struct pstore_info *psi)
 	 * Update the module parameter backend, so it is visible
 	 * through /sys/module/pstore/parameters/backend
 	 */
-	backend = kstrdup(psi->name, GFP_KERNEL);
+	backend = new_backend;
 
 	pr_info("Registered %s as persistent store backend\n", psi->name);