omfs: sanity check cluster size
A corrupt filesystem could have a bad cluster size; this could result in
the filesystem allocating too much space for files if too large, or
getting stuck in omfs_allocate_block if too small. The proper range is
1-8 blocks.
Reported-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
diff --git a/fs/omfs/inode.c b/fs/omfs/inode.c
index 0af5d0a..579d33f 100644
--- a/fs/omfs/inode.c
+++ b/fs/omfs/inode.c
@@ -517,6 +517,12 @@
(unsigned long long) sbi->s_num_blocks);
goto out_brelse_bh2;
}
+ if (sbi->s_clustersize < 1 ||
+ sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) {
+ printk(KERN_ERR "omfs: cluster size out of range (%d)",
+ sbi->s_clustersize);
+ goto out_brelse_bh2;
+ }
ret = omfs_get_imap(sb);
if (ret)
diff --git a/fs/omfs/omfs_fs.h b/fs/omfs/omfs_fs.h
index 12cca24..ee5e432 100644
--- a/fs/omfs/omfs_fs.h
+++ b/fs/omfs/omfs_fs.h
@@ -17,6 +17,7 @@
#define OMFS_EXTENT_CONT 0x40
#define OMFS_XOR_COUNT 19
#define OMFS_MAX_BLOCK_SIZE 8192
+#define OMFS_MAX_CLUSTER_SIZE 8
struct omfs_super_block {
char s_fill1[256];