From 26dbb30c58ffb85bc015bd5e58831483d50f7d18 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 29 Mar 2018 22:10:31 -0400 Subject: [PATCH] ext4: always initialize the crc32c checksum driver commit a45403b51582a87872927a3e0fc0a389c26867f1 upstream. The extended attribute code now uses the crc32c checksum for hashing purposes, so we should just always always initialize it. We also want to prevent NULL pointer dereferences if one of the metadata checksum features is enabled after the file sytsem is originally mounted. This issue has been assigned CVE-2018-1094. https://bugzilla.kernel.org/show_bug.cgi?id=199183 https://bugzilla.redhat.com/show_bug.cgi?id=1560788 Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/super.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 16d247f056e2..1339a79eb314 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3490,15 +3490,12 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } /* Load the checksum driver */ - if (ext4_has_feature_metadata_csum(sb) || - ext4_has_feature_ea_inode(sb)) { - sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0); - if (IS_ERR(sbi->s_chksum_driver)) { - ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver."); - ret = PTR_ERR(sbi->s_chksum_driver); - sbi->s_chksum_driver = NULL; - goto failed_mount; - } + sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0); + if (IS_ERR(sbi->s_chksum_driver)) { + ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver."); + ret = PTR_ERR(sbi->s_chksum_driver); + sbi->s_chksum_driver = NULL; + goto failed_mount; } /* Check superblock checksum */ -- 2.20.1