1 files changed, 45 insertions, 0 deletions

diff --git a/fs/bfs/inode.c b/fs/bfs/inode.c
index 0ed57b5ee012..cc4062d12ca2 100644
--- a/fs/bfs/inode.c
+++ b/fs/bfs/inode.c
@@ -213,6 +213,9 @@ static void bfs_put_super(struct super_block *s)
 {
         struct bfs_sb_info *info = BFS_SB(s);
 
+        if (!info)
+                return;
+
         brelse(info->si_sbh);
         mutex_destroy(&info->bfs_lock);
         kfree(info->si_imap);
@@ -327,6 +330,7 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent)
         unsigned i, imap_len;
         struct bfs_sb_info *info;
         long ret = -EINVAL;
+        unsigned long i_sblock, i_eblock, i_eoff, s_size;
 
         info = kzalloc(sizeof(*info), GFP_KERNEL);
         if (!info)
@@ -350,6 +354,12 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent)
 
         s->s_magic = BFS_MAGIC;
         info->si_sbh = bh;
+
+        if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
+                printf("Superblock is corrupted\n");
+                goto out;
+        }
+
         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
                                         sizeof(struct bfs_inode)
                                         + BFS_ROOT_INO - 1;
@@ -380,6 +390,18 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent)
                         - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
         info->si_freei = 0;
         info->si_lf_eblk = 0;
+
+        /* can we read the last block? */
+        bh = sb_bread(s, info->si_blocks - 1);
+        if (!bh) {
+                printf("Last block not available: %lu\n", info->si_blocks - 1);
+                iput(inode);
+                ret = -EIO;
+                kfree(info->si_imap);
+                goto out;
+        }
+        brelse(bh);
+
         bh = NULL;
         for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
                 struct bfs_inode *di;
@@ -397,6 +419,29 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent)
 
                 di = (struct bfs_inode *)bh->b_data + off;
 
+                /* test if filesystem is not corrupted */
+
+                i_eoff = le32_to_cpu(di->i_eoffset);
+                i_sblock = le32_to_cpu(di->i_sblock);
+                i_eblock = le32_to_cpu(di->i_eblock);
+                s_size = le32_to_cpu(bfs_sb->s_end);
+
+                if (i_sblock > info->si_blocks ||
+                        i_eblock > info->si_blocks ||
+                        i_sblock > i_eblock ||
+                        i_eoff > s_size ||
+                        i_sblock * BFS_BSIZE > i_eoff) {
+
+                        printf("Inode 0x%08x corrupted\n", i);
+
+                        brelse(bh);
+                        s->s_root = NULL;
+                        kfree(info->si_imap);
+                        kfree(info);
+                        s->s_fs_info = NULL;
+                        return -EIO;
+                }
+
                 if (!di->i_ino) {
                         info->si_freei++;
                         continue;