boot/grub2/0126-fs-btrfs-Squash-some-uninitialized-reads.patch

From b911884dd707ba1e6f641eb17857df3155013a45 Mon Sep 17 00:00:00 2001
From: Daniel Axtens <dja@axtens.net>
Date: Mon, 18 Jan 2021 17:27:18 +1100
Subject: [PATCH] fs/btrfs: Squash some uninitialized reads

We need to check errors before calling into a function that uses the result.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
---
 grub-core/fs/btrfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c
index e4e87ba..d489cb0 100644
--- a/grub-core/fs/btrfs.c
+++ b/grub-core/fs/btrfs.c
@@ -381,9 +381,9 @@ next (struct grub_btrfs_data *data,
 
       err = grub_btrfs_read_logical (data, grub_le_to_cpu64 (node.addr),
 				     &head, sizeof (head), 0);
-      check_btrfs_header (data, &head, grub_le_to_cpu64 (node.addr));
       if (err)
 	return -err;
+      check_btrfs_header (data, &head, grub_le_to_cpu64 (node.addr));
 
       save_ref (desc, grub_le_to_cpu64 (node.addr), 0,
 		grub_le_to_cpu32 (head.nitems), !head.level);
@@ -443,9 +443,9 @@ lower_bound (struct grub_btrfs_data *data,
       /* FIXME: preread few nodes into buffer. */
       err = grub_btrfs_read_logical (data, addr, &head, sizeof (head),
 				     recursion_depth + 1);
-      check_btrfs_header (data, &head, addr);
       if (err)
 	return err;
+      check_btrfs_header (data, &head, addr);
       addr += sizeof (head);
       if (head.level)
 	{
-- 
2.14.2