From 4ae1d69bedc8d174cb8a558694607e013157cde1 Mon Sep 17 00:00:00 2001 From: Joel Becker Date: Thu, 13 Nov 2008 14:49:18 -0800 Subject: [PATCH] ocfs2: Wrap xattr block reads in a dedicated function We weren't consistently checking xattr blocks after we read them. Most places checked the signature, but none checked xb_blkno or xb_fs_signature. Create a toplevel ocfs2_read_xattr_block() that does the read and the validation. Signed-off-by: Joel Becker Signed-off-by: Mark Fasheh --- fs/ocfs2/xattr.c | 94 +++++++++++++++++++++++++++++++++++------------- 1 file changed, 70 insertions(+), 24 deletions(-) diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c index 3cc8385f973..ef4aa5482d0 100644 --- a/fs/ocfs2/xattr.c +++ b/fs/ocfs2/xattr.c @@ -314,6 +314,65 @@ static void ocfs2_xattr_bucket_copy_data(struct ocfs2_xattr_bucket *dest, } } +static int ocfs2_validate_xattr_block(struct super_block *sb, + struct buffer_head *bh) +{ + struct ocfs2_xattr_block *xb = + (struct ocfs2_xattr_block *)bh->b_data; + + mlog(0, "Validating xattr block %llu\n", + (unsigned long long)bh->b_blocknr); + + if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) { + ocfs2_error(sb, + "Extended attribute block #%llu has bad " + "signature %.*s", + (unsigned long long)bh->b_blocknr, 7, + xb->xb_signature); + return -EINVAL; + } + + if (le64_to_cpu(xb->xb_blkno) != bh->b_blocknr) { + ocfs2_error(sb, + "Extended attribute block #%llu has an " + "invalid xb_blkno of %llu", + (unsigned long long)bh->b_blocknr, + (unsigned long long)le64_to_cpu(xb->xb_blkno)); + return -EINVAL; + } + + if (le32_to_cpu(xb->xb_fs_generation) != OCFS2_SB(sb)->fs_generation) { + ocfs2_error(sb, + "Extended attribute block #%llu has an invalid " + "xb_fs_generation of #%u", + (unsigned long long)bh->b_blocknr, + le32_to_cpu(xb->xb_fs_generation)); + return -EINVAL; + } + + return 0; +} + +static int ocfs2_read_xattr_block(struct inode *inode, u64 xb_blkno, + struct buffer_head **bh) +{ + int rc; + struct buffer_head *tmp = *bh; + + rc = ocfs2_read_block(inode, xb_blkno, &tmp); + if (!rc) { + rc = ocfs2_validate_xattr_block(inode->i_sb, tmp); + if (rc) + brelse(tmp); + } + + /* If ocfs2_read_block() got us a new bh, pass it up. */ + if (!rc && !*bh) + *bh = tmp; + + return rc; +} + static inline const char *ocfs2_xattr_prefix(int name_index) { struct xattr_handler *handler = NULL; @@ -739,18 +798,14 @@ static int ocfs2_xattr_block_list(struct inode *inode, if (!di->i_xattr_loc) return ret; - ret = ocfs2_read_block(inode, le64_to_cpu(di->i_xattr_loc), &blk_bh); + ret = ocfs2_read_xattr_block(inode, le64_to_cpu(di->i_xattr_loc), + &blk_bh); if (ret < 0) { mlog_errno(ret); return ret; } xb = (struct ocfs2_xattr_block *)blk_bh->b_data; - if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) { - ret = -EIO; - goto cleanup; - } - if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) { struct ocfs2_xattr_header *header = &xb->xb_attrs.xb_header; ret = ocfs2_xattr_list_entries(inode, header, @@ -760,7 +815,7 @@ static int ocfs2_xattr_block_list(struct inode *inode, ret = ocfs2_xattr_tree_list_index_block(inode, xt, buffer, buffer_size); } -cleanup: + brelse(blk_bh); return ret; @@ -1693,24 +1748,19 @@ static int ocfs2_xattr_free_block(struct inode *inode, u64 blk, bg_blkno; u16 bit; - ret = ocfs2_read_block(inode, block, &blk_bh); + ret = ocfs2_read_xattr_block(inode, block, &blk_bh); if (ret < 0) { mlog_errno(ret); goto out; } - xb = (struct ocfs2_xattr_block *)blk_bh->b_data; - if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) { - ret = -EIO; - goto out; - } - ret = ocfs2_xattr_block_remove(inode, blk_bh); if (ret < 0) { mlog_errno(ret); goto out; } + xb = (struct ocfs2_xattr_block *)blk_bh->b_data; blk = le64_to_cpu(xb->xb_blkno); bit = le16_to_cpu(xb->xb_suballoc_bit); bg_blkno = ocfs2_which_suballoc_group(blk, bit); @@ -1950,19 +2000,15 @@ static int ocfs2_xattr_block_find(struct inode *inode, if (!di->i_xattr_loc) return ret; - ret = ocfs2_read_block(inode, le64_to_cpu(di->i_xattr_loc), &blk_bh); + ret = ocfs2_read_xattr_block(inode, le64_to_cpu(di->i_xattr_loc), + &blk_bh); if (ret < 0) { mlog_errno(ret); return ret; } - xb = (struct ocfs2_xattr_block *)blk_bh->b_data; - if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) { - ret = -EIO; - goto cleanup; - } - xs->xattr_bh = blk_bh; + xb = (struct ocfs2_xattr_block *)blk_bh->b_data; if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) { xs->header = &xb->xb_attrs.xb_header; @@ -2259,9 +2305,9 @@ meta_guess: /* calculate metadata allocation. */ if (di->i_xattr_loc) { if (!xbs->xattr_bh) { - ret = ocfs2_read_block(inode, - le64_to_cpu(di->i_xattr_loc), - &bh); + ret = ocfs2_read_xattr_block(inode, + le64_to_cpu(di->i_xattr_loc), + &bh); if (ret) { mlog_errno(ret); goto out; -- 2.41.1