From c24aab6d86640ccf321b87be6096319f55b16274 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sun, 17 Jun 2018 00:41:14 -0400 Subject: [PATCH] ext4: add more inode number paranoia checks commit c37e9e013469521d9adb932d17a1795c139b36db upstream. If there is a directory entry pointing to a system inode (such as a journal inode), complain and declare the file system to be corrupted. Also, if the superblock's first inode number field is too small, refuse to mount the file system. This addresses CVE-2018-10882. https://bugzilla.kernel.org/show_bug.cgi?id=200069 Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/ext4.h | 5 ----- fs/ext4/inode.c | 3 ++- fs/ext4/super.c | 5 +++++ 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index db389611f8bc..0abb30d19fa1 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1542,11 +1542,6 @@ static inline struct ext4_inode_info *EXT4_I(struct inode *inode) static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino) { return ino == EXT4_ROOT_INO || - ino == EXT4_USR_QUOTA_INO || - ino == EXT4_GRP_QUOTA_INO || - ino == EXT4_BOOT_LOADER_INO || - ino == EXT4_JOURNAL_INO || - ino == EXT4_RESIZE_INO || (ino >= EXT4_FIRST_INO(sb) && ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)); } diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 5b28153eb0fd..c2efe4d2ad87 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4455,7 +4455,8 @@ static int __ext4_get_inode_loc(struct inode *inode, int inodes_per_block, inode_offset; iloc->bh = NULL; - if (!ext4_valid_inum(sb, inode->i_ino)) + if (inode->i_ino < EXT4_ROOT_INO || + inode->i_ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)) return -EFSCORRUPTED; iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb); diff --git a/fs/ext4/super.c b/fs/ext4/super.c index fefcfa9fe408..6933efbb582f 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3811,6 +3811,11 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } else { sbi->s_inode_size = le16_to_cpu(es->s_inode_size); sbi->s_first_ino = le32_to_cpu(es->s_first_ino); + if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) { + ext4_msg(sb, KERN_ERR, "invalid first ino: %u", + sbi->s_first_ino); + goto failed_mount; + } if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) || (!is_power_of_2(sbi->s_inode_size)) || (sbi->s_inode_size > blocksize)) { -- 2.20.1