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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Dan Carpenter <dan.carpenter@oracle.com>,
        Harshad Shirwadkar <harshadshirwadkar@gmail.com>,
        Theodore Tso <tytso@mit.edu>, stable@kernel.org
Subject: [PATCH 5.15 716/846] ext4: initialize err_blk before calling __ext4_get_inode_loc
Date:   Mon, 24 Jan 2022 19:43:53 +0100
Message-Id: <20220124184125.722082359@linuxfoundation.org>
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From: Harshad Shirwadkar <harshadshirwadkar@gmail.com>

commit c27c29c6af4f3f4ce925a2111c256733c5a5b430 upstream.

It is not guaranteed that __ext4_get_inode_loc will definitely set
err_blk pointer when it returns EIO. To avoid using uninitialized
variables, let's first set err_blk to 0.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20211201163421.2631661-1-harshads@google.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/ext4/inode.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4371,7 +4371,7 @@ has_buffer:
 static int __ext4_get_inode_loc_noinmem(struct inode *inode,
 					struct ext4_iloc *iloc)
 {
-	ext4_fsblk_t err_blk;
+	ext4_fsblk_t err_blk = 0;
 	int ret;
 
 	ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, iloc, 0,
@@ -4386,7 +4386,7 @@ static int __ext4_get_inode_loc_noinmem(
 
 int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
 {
-	ext4_fsblk_t err_blk;
+	ext4_fsblk_t err_blk = 0;
 	int ret;
 
 	/* We have all inode data except xattrs in memory here. */