6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
[ 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>
---
fs/pstore/platform.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index e5bca9a004ccc..03425928d2fb3 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -464,6 +464,8 @@ 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("backend '%s' already in use: ignoring '%s'\n",
backend, psi->name);
@@ -484,11 +486,16 @@ 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;
}
@@ -521,7 +528,7 @@ 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);
--
2.42.0
