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 16:26:44 +0200 |
| commit | 425dc465de3725210162da9b1e9062e86cc2de27 (patch) | |
| tree | ec44d5694e65c9667891e31733de2de3393c46b8 | |
| parent | a5e063d348bd2ef14fff96b129749409a8991ea5 (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>
| -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 a8a750f59621..43e27d8ec770 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1542,11 +1542,6 @@ 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 81b16c3eccd4..5c4c9af4aaf4 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4242,7 +4242,8 @@ 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 4c5d9df1790a..25e078e839fb 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3713,6 +3713,11 @@ 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)) { |