From a0c57f8759a0548aa7f0334f6839156b1456bb2a Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Wed, 13 Jun 2018 09:57:49 -0400
Subject: [PATCH 2/2] libfwup: set_up_boot_next(): make sure we check if our
 file paths are NULL.

Coverity's clang scan believes we can sometimes alloca(0) if
fwup_esp_path is NULL, though I don't think this can happen because if
it is NULL get_paths() should have returned error.  Nevertheless, just
check both things.

Additionally, this adds a check to make sure utf8_to_ucs2() and
ucs2len() didn't fail.

Signed-off-by: Peter Jones <pjones@redhat.com>
---
 linux/libfwup.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/linux/libfwup.c b/linux/libfwup.c
index abab18e96ac..61a9d280c32 100644
--- a/linux/libfwup.c
+++ b/linux/libfwup.c
@@ -1215,9 +1215,9 @@ set_up_boot_next(void)
 	uint32_t attributes = LOAD_OPTION_ACTIVE;
 
 	rc = get_paths(&shim_fs_path, &fwup_fs_path, &fwup_esp_path);
-	if (rc < 0) {
+	if (rc < 0 || (!shim_fs_path && (!fwup_fs_path || !fwup_esp_path))) {
 		efi_error("could not find paths for shim and fwup");
-		return -1;
+                goto out;
 	}
 
 	if (!shim_fs_path)
@@ -1242,9 +1242,20 @@ set_up_boot_next(void)
 
 	if (!use_fwup_path) {
 		loader_str = utf8_to_ucs2((uint8_t *)fwup_esp_path, -1);
+		if (loader_str == NULL) {
+			efi_error("utf8_to_ucs2() failed");
+			goto out;
+		}
 		loader_sz = ucs2len(loader_str, -1) * 2;
-		if (loader_sz)
-			loader_sz += 2;
+		if (loader_sz < 2) {
+			efi_error("ucs2len(fwup_esp_path) returned %zu",
+				  loader_sz);
+			saved_errno = errno;
+			free(loader_str);
+			errno = saved_errno;
+			goto out;
+		}
+		loader_sz += 2;
 		loader_str = onstack(loader_str, loader_sz);
 	}
 
-- 
2.17.1