From f068272cb2f134a194b93e94a8e0672bfce48cd8 Mon Sep 17 00:00:00 2001 From: Bob Copeland Date: Sat, 6 Sep 2008 17:51:53 -0400 Subject: omfs: check bounds on block numbers before passing to sb_bread In case of filesystem corruption, passing unchecked block numbers into sb_bread can result in an infinite loop in __getblk(). Introduce a wrapper function omfs_sbread() to check the block numbers and to also perform the clus_to_blk() scaling. Signed-off-by: Bob Copeland --- fs/omfs/inode.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) (limited to 'fs/omfs/inode.c') diff --git a/fs/omfs/inode.c b/fs/omfs/inode.c index b5d6380e03fb..bd4bf753a63b 100644 --- a/fs/omfs/inode.c +++ b/fs/omfs/inode.c @@ -19,6 +19,15 @@ MODULE_AUTHOR("Bob Copeland "); MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux"); MODULE_LICENSE("GPL"); +struct buffer_head *omfs_bread(struct super_block *sb, sector_t block) +{ + struct omfs_sb_info *sbi = OMFS_SB(sb); + if (block >= sbi->s_num_blocks) + return NULL; + + return sb_bread(sb, clus_to_blk(sbi, block)); +} + struct inode *omfs_new_inode(struct inode *dir, int mode) { struct inode *inode; @@ -93,15 +102,13 @@ static int __omfs_write_inode(struct inode *inode, int wait) struct omfs_inode *oi; struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb); struct buffer_head *bh, *bh2; - unsigned int block; u64 ctime; int i; int ret = -EIO; int sync_failed = 0; /* get current inode since we may have written sibling ptrs etc. */ - block = clus_to_blk(sbi, inode->i_ino); - bh = sb_bread(inode->i_sb, block); + bh = omfs_bread(inode->i_sb, inode->i_ino); if (!bh) goto out; @@ -140,8 +147,7 @@ static int __omfs_write_inode(struct inode *inode, int wait) /* if mirroring writes, copy to next fsblock */ for (i = 1; i < sbi->s_mirrors; i++) { - bh2 = sb_bread(inode->i_sb, block + i * - (sbi->s_blocksize / sbi->s_sys_blocksize)); + bh2 = omfs_bread(inode->i_sb, inode->i_ino + i); if (!bh2) goto out_brelse; @@ -193,7 +199,6 @@ struct inode *omfs_iget(struct super_block *sb, ino_t ino) struct omfs_sb_info *sbi = OMFS_SB(sb); struct omfs_inode *oi; struct buffer_head *bh; - unsigned int block; u64 ctime; unsigned long nsecs; struct inode *inode; @@ -204,8 +209,7 @@ struct inode *omfs_iget(struct super_block *sb, ino_t ino) if (!(inode->i_state & I_NEW)) return inode; - block = clus_to_blk(sbi, ino); - bh = sb_bread(inode->i_sb, block); + bh = omfs_bread(inode->i_sb, ino); if (!bh) goto iget_failed; @@ -319,6 +323,9 @@ static int omfs_get_imap(struct super_block *sb) goto nomem; block = clus_to_blk(sbi, sbi->s_bitmap_ino); + if (block >= sbi->s_num_blocks) + goto nomem; + ptr = sbi->s_imap; for (count = bitmap_size; count > 0; count -= sb->s_blocksize) { bh = sb_bread(sb, block++); @@ -417,7 +424,6 @@ static int omfs_fill_super(struct super_block *sb, void *data, int silent) struct omfs_root_block *omfs_rb; struct omfs_sb_info *sbi; struct inode *root; - sector_t start; int ret = -EINVAL; save_mount_options(sb, (char *) data); @@ -486,8 +492,7 @@ static int omfs_fill_super(struct super_block *sb, void *data, int silent) sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) - get_bitmask_order(sbi->s_sys_blocksize); - start = clus_to_blk(sbi, be64_to_cpu(omfs_sb->s_root_block)); - bh2 = sb_bread(sb, start); + bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block)); if (!bh2) goto out_brelse_bh; -- cgit v1.2.3