Patch "pstore/platform: Add check for kstrdup" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    pstore/platform: Add check for kstrdup

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     pstore-platform-add-check-for-kstrdup.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit e384beef309da2c7d0e211f19129261e8759337a
Author: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
Date:   Fri Jun 23 10:27:06 2023 +0800

    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@xxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20230623022706.32125-1-jiasheng@xxxxxxxxxxx
    Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index ad96ba97d8f97..3fc4739f82d86 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -561,6 +561,8 @@ static int pstore_write_user_compat(struct pstore_record *record,
  */
 int pstore_register(struct pstore_info *psi)
 {
+	char *new_backend;
+
 	if (backend && strcmp(backend, psi->name)) {
 		pr_warn("ignoring unexpected backend '%s'\n", psi->name);
 		return -EPERM;
@@ -580,11 +582,16 @@ 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;
 	}
 
@@ -617,7 +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 = kstrdup(psi->name, GFP_KERNEL);
+	backend = new_backend;
 
 	pr_info("Registered %s as persistent store backend\n", psi->name);