From a40aefc0a7122bbb7b5ec07e3fc5388b16f6621b 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 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 Gbp-Pq: Topic bugfix/all Gbp-Pq: Name ext4-always-initialize-the-crc32c-checksum-driver.patch --- 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 26adff002e8..01d318831dd 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3489,15 +3489,12 @@ 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 */ -- 2.30.2