5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jiasheng Jiang jiasheng@iscas.ac.cn
[ 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 --- 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 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);