diff options
| author | Theodore Ts'o <tytso@mit.edu> | 2018-06-17 00:41:14 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-11 16:03:49 +0200 |
| commit | ff6c96461be35381399466ad58f02b8d78ab480a (patch) | |
| tree | 8f59e7eee7b4a1eb7b27d5c288adc755fcd2bb15 /fs | |
| parent | b88fc699a023e0ef86f647c3d48a17d7cfff1f2a (diff) | |
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 <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/ext4.h | 5 | ||||
| -rw-r--r-- | fs/ext4/inode.c | 3 | ||||
| -rw-r--r-- | 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 c8ad14c697c4..f5d9f82b173a 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1468,11 +1468,6 @@ static inline struct timespec ext4_current_time(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 b8f4394971c8..b507de0e4bbf 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3991,7 +3991,8 @@ 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 4cff3ff7b9e0..9762fde91fb5 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3549,6 +3549,11 @@ 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)) { |