diff options
| author | Theodore Ts'o <tytso@mit.edu> | 2016-11-18 13:00:24 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-11-26 09:54:52 +0100 |
| commit | 454cf79b05c566806ead785514f36fea0b129a28 (patch) | |
| tree | 13377b3af05352efef57e5c05198e74b0323cb54 /fs/ext4/super.c | |
| parent | 147117cf23c0ba452f80409aec9c0be978232698 (diff) | |
ext4: sanity check the block and cluster size at mount time
commit 8cdf3372fe8368f56315e66bea9f35053c418093 upstream.
If the block size or cluster size is insane, reject the mount. This
is important for security reasons (although we shouldn't be just
depending on this check).
Ref: http://www.securityfocus.com/archive/1/539661
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1332506
Reported-by: Borislav Petkov <bp@alien8.de>
Reported-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ext4/super.c')
| -rw-r--r-- | fs/ext4/super.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 5bab28caa9d4..127155b82e6e 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3394,7 +3394,15 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) if (blocksize < EXT4_MIN_BLOCK_SIZE || blocksize > EXT4_MAX_BLOCK_SIZE) { ext4_msg(sb, KERN_ERR, - "Unsupported filesystem blocksize %d", blocksize); + "Unsupported filesystem blocksize %d (%d log_block_size)", + blocksize, le32_to_cpu(es->s_log_block_size)); + goto failed_mount; + } + if (le32_to_cpu(es->s_log_block_size) > + (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) { + ext4_msg(sb, KERN_ERR, + "Invalid log block size: %u", + le32_to_cpu(es->s_log_block_size)); goto failed_mount; } @@ -3533,6 +3541,13 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) "block size (%d)", clustersize, blocksize); goto failed_mount; } + if (le32_to_cpu(es->s_log_cluster_size) > + (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) { + ext4_msg(sb, KERN_ERR, + "Invalid log cluster size: %u", + le32_to_cpu(es->s_log_cluster_size)); + goto failed_mount; + } sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) - le32_to_cpu(es->s_log_block_size); sbi->s_clusters_per_group = |