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Signed-off-by: lei lu --- fs/ocfs2/dir.c | 39 +++++++++++++++++++++++++-------------- 1 file changed, 25 insertions(+), 14 deletions(-) diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c index d620d4c53c6f..cdd92b4f9bf1 100644 --- a/fs/ocfs2/dir.c +++ b/fs/ocfs2/dir.c @@ -294,13 +294,16 @@ static void ocfs2_dx_dir_name_hash(struct inode *dir, const char *name, int len, * bh passed here can be an inode block or a dir data block, depending * on the inode inline data flag. */ -static int ocfs2_check_dir_entry(struct inode * dir, - struct ocfs2_dir_entry * de, - struct buffer_head * bh, +static int ocfs2_check_dir_entry(struct inode *dir, + struct ocfs2_dir_entry *de, + struct buffer_head *bh, + char *buf, + unsigned int size, unsigned long offset) { const char *error_msg = NULL; const int rlen = le16_to_cpu(de->rec_len); + const unsigned long next_offset = ((char *) de - buf) + rlen; if (unlikely(rlen < OCFS2_DIR_REC_LEN(1))) error_msg = "rec_len is smaller than minimal"; @@ -308,6 +311,11 @@ static int ocfs2_check_dir_entry(struct inode * dir, error_msg = "rec_len % 4 != 0"; else if (unlikely(rlen < OCFS2_DIR_REC_LEN(de->name_len))) error_msg = "rec_len is too small for name_len"; + else if (unlikely(next_offset > size)) + error_msg = "directory entry overrun"; + else if (unlikely(next_offset > size - OCFS2_DIR_REC_LEN(1)) && + next_offset != size) + error_msg = "directory entry too close to end"; else if (unlikely( ((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)) error_msg = "directory entry across blocks"; @@ -352,16 +360,16 @@ static inline int ocfs2_search_dirblock(struct buffer_head *bh, de_buf = first_de; dlimit = de_buf + bytes; - while (de_buf < dlimit) { + while (de_buf < dlimit - OCFS2_DIR_MEMBER_LEN) { /* this code is executed quadratically often */ /* do minimal checking `by hand' */ de = (struct ocfs2_dir_entry *) de_buf; - if (de_buf + namelen <= dlimit && + if (de->name + namelen <= dlimit && ocfs2_match(namelen, name, de)) { /* found a match - just to be sure, do a full check */ - if (!ocfs2_check_dir_entry(dir, de, bh, offset)) { + if (!ocfs2_check_dir_entry(dir, de, bh, first_de, bytes, offset)) { ret = -1; goto bail; } @@ -1138,7 +1146,7 @@ static int __ocfs2_delete_entry(handle_t *handle, struct inode *dir, pde = NULL; de = (struct ocfs2_dir_entry *) first_de; while (i < bytes) { - if (!ocfs2_check_dir_entry(dir, de, bh, i)) { + if (!ocfs2_check_dir_entry(dir, de, bh, first_de, bytes, i)) { status = -EIO; mlog_errno(status); goto bail; @@ -1635,7 +1643,7 @@ int __ocfs2_add_entry(handle_t *handle, /* These checks should've already been passed by the * prepare function, but I guess we can leave them * here anyway. */ - if (!ocfs2_check_dir_entry(dir, de, insert_bh, offset)) { + if (!ocfs2_check_dir_entry(dir, de, insert_bh, data_start, size, offset)) { retval = -ENOENT; goto bail; } @@ -1774,7 +1782,8 @@ static int ocfs2_dir_foreach_blk_id(struct inode *inode, } de = (struct ocfs2_dir_entry *) (data->id_data + ctx->pos); - if (!ocfs2_check_dir_entry(inode, de, di_bh, ctx->pos)) { + if (!ocfs2_check_dir_entry(inode, de, di_bh, (char *)data->id_data, + i_size_read(inode), ctx->pos)) { /* On error, skip the f_pos to the end. */ ctx->pos = i_size_read(inode); break; @@ -1867,7 +1876,8 @@ static int ocfs2_dir_foreach_blk_el(struct inode *inode, while (ctx->pos < i_size_read(inode) && offset < sb->s_blocksize) { de = (struct ocfs2_dir_entry *) (bh->b_data + offset); - if (!ocfs2_check_dir_entry(inode, de, bh, offset)) { + if (!ocfs2_check_dir_entry(inode, de, bh, bh->b_data, + sb->s_blocksize, offset)) { /* On error, skip the f_pos to the next block. */ ctx->pos = (ctx->pos | (sb->s_blocksize - 1)) + 1; @@ -3339,7 +3349,7 @@ static int ocfs2_find_dir_space_id(struct inode *dir, struct buffer_head *di_bh, struct super_block *sb = dir->i_sb; struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data; struct ocfs2_dir_entry *de, *last_de = NULL; - char *de_buf, *limit; + char *first_de, *de_buf, *limit; unsigned long offset = 0; unsigned int rec_len, new_rec_len, free_space; @@ -3352,14 +3362,15 @@ static int ocfs2_find_dir_space_id(struct inode *dir, struct buffer_head *di_bh, else free_space = dir->i_sb->s_blocksize - i_size_read(dir); - de_buf = di->id2.i_data.id_data; + first_de = di->id2.i_data.id_data; + de_buf = first_de; limit = de_buf + i_size_read(dir); rec_len = OCFS2_DIR_REC_LEN(namelen); while (de_buf < limit) { de = (struct ocfs2_dir_entry *)de_buf; - if (!ocfs2_check_dir_entry(dir, de, di_bh, offset)) { + if (!ocfs2_check_dir_entry(dir, de, di_bh, first_de, i_size_read(dir), offset)) { ret = -ENOENT; goto out; } @@ -3441,7 +3452,7 @@ static int ocfs2_find_dir_space_el(struct inode *dir, const char *name, /* move to next block */ de = (struct ocfs2_dir_entry *) bh->b_data; } - if (!ocfs2_check_dir_entry(dir, de, bh, offset)) { + if (!ocfs2_check_dir_entry(dir, de, bh, bh->b_data, blocksize, offset)) { status = -ENOENT; goto bail; }