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| author | Theodore Ts'o <tytso@mit.edu> | 2018-06-17 07:41:14 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2018-06-17 07:41:14 +0300 |
| commit | c37e9e013469521d9adb932d17a1795c139b36db (patch) | |
| tree | a7a39bc1259d9c8398817a5c7c05fcc87e8f6bb6 /fs/ext4/super.c | |
| parent | 8bc1379b82b8e809eef77a9fedbb75c6c297be19 (diff) | |
| download | linux-c37e9e013469521d9adb932d17a1795c139b36db.tar.xz | |
ext4: add more inode number paranoia checks
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
Diffstat (limited to 'fs/ext4/super.c')
| -rw-r--r-- | fs/ext4/super.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 4d34430d75f6..1f955c128e0d 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3858,6 +3858,11 @@ 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)) { |