diff options
| -rw-r--r-- | fs/ext4/inode.c | 59 |
1 files changed, 52 insertions, 7 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c7d9250fbc3f..b3fd65d46506 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -371,6 +371,34 @@ static int ext4_block_to_path(struct inode *inode, return n; } +static int __ext4_check_blockref(const char *function, struct inode *inode, + unsigned int *p, unsigned int max) { + + unsigned int maxblocks = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es); + unsigned int *bref = p; + while (bref < p+max) { + if (unlikely(*bref >= maxblocks)) { + ext4_error(inode->i_sb, function, + "block reference %u >= max (%u) " + "in inode #%lu, offset=%d", + *bref, maxblocks, + inode->i_ino, (int)(bref-p)); + return -EIO; + } + bref++; + } + return 0; +} + + +#define ext4_check_indirect_blockref(inode, bh) \ + __ext4_check_blockref(__func__, inode, (__le32 *)(bh)->b_data, \ + EXT4_ADDR_PER_BLOCK((inode)->i_sb)) + +#define ext4_check_inode_blockref(inode) \ + __ext4_check_blockref(__func__, inode, EXT4_I(inode)->i_data, \ + EXT4_NDIR_BLOCKS) + /** * ext4_get_branch - read the chain of indirect blocks leading to data * @inode: inode in question @@ -415,9 +443,22 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth, if (!p->key) goto no_block; while (--depth) { - bh = sb_bread(sb, le32_to_cpu(p->key)); - if (!bh) + bh = sb_getblk(sb, le32_to_cpu(p->key)); + if (unlikely(!bh)) goto failure; + + if (!bh_uptodate_or_lock(bh)) { + if (bh_submit_read(bh) < 0) { + put_bh(bh); + goto failure; + } + /* validate block references */ + if (ext4_check_indirect_blockref(inode, bh)) { + put_bh(bh); + goto failure; + } + } + add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets); /* Reader: end */ if (!p->key) @@ -4371,11 +4412,15 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) if (ei->i_flags & EXT4_EXTENTS_FL) { /* Validate extent which is part of inode */ ret = ext4_ext_check_inode(inode); - if (ret) { - brelse(bh); - goto bad_inode; - } - + } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || + (S_ISLNK(inode->i_mode) && + !ext4_inode_is_fast_symlink(inode))) { + /* Validate block references which are part of inode */ + ret = ext4_check_inode_blockref(inode); + } + if (ret) { + brelse(bh); + goto bad_inode; } if (S_ISREG(inode->i_mode)) { |