1 files changed, 19 insertions, 12 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 2a45e0d3e593..d931252b7d0d 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -390,9 +390,12 @@ static int ext4_valid_extent_idx(struct inode *inode,
 
 static int ext4_valid_extent_entries(struct inode *inode,
 				struct ext4_extent_header *eh,
-				int depth)
+				ext4_fsblk_t *pblk, int depth)
 {
 	unsigned short entries;
+	ext4_lblk_t lblock = 0;
+	ext4_lblk_t prev = 0;
+
 	if (eh->eh_entries == 0)
 		return 1;
 
@@ -403,32 +406,36 @@ static int ext4_valid_extent_entries(struct inode *inode,
 		struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
 		struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 		ext4_fsblk_t pblock = 0;
-		ext4_lblk_t lblock = 0;
-		ext4_lblk_t prev = 0;
-		int len = 0;
 		while (entries) {
 			if (!ext4_valid_extent(inode, ext))
 				return 0;
 
 			/* Check for overlapping extents */
 			lblock = le32_to_cpu(ext->ee_block);
-			len = ext4_ext_get_actual_len(ext);
 			if ((lblock <= prev) && prev) {
 				pblock = ext4_ext_pblock(ext);
 				es->s_last_error_block = cpu_to_le64(pblock);
 				return 0;
 			}
+			prev = lblock + ext4_ext_get_actual_len(ext) - 1;
 			ext++;
 			entries--;
-			prev = lblock + len - 1;
 		}
 	} else {
 		struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
 		while (entries) {
 			if (!ext4_valid_extent_idx(inode, ext_idx))
 				return 0;
+
+			/* Check for overlapping index extents */
+			lblock = le32_to_cpu(ext_idx->ei_block);
+			if ((lblock <= prev) && prev) {
+				*pblk = ext4_idx_pblock(ext_idx);
+				return 0;
+			}
 			ext_idx++;
 			entries--;
+			prev = lblock;
 		}
 	}
 	return 1;
@@ -462,7 +469,7 @@ static int __ext4_ext_check(const char *function, unsigned int line,
 		error_msg = "invalid eh_entries";
 		goto corrupted;
 	}
-	if (!ext4_valid_extent_entries(inode, eh, depth)) {
+	if (!ext4_valid_extent_entries(inode, eh, &pblk, depth)) {
 		error_msg = "invalid extent entries";
 		goto corrupted;
 	}
@@ -990,6 +997,11 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 		ix = curp->p_idx;
 	}
 
+	if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
+		EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
+		return -EFSCORRUPTED;
+	}
+
 	len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
 	BUG_ON(len < 0);
 	if (len > 0) {
@@ -999,11 +1011,6 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 		memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
 	}
 
-	if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
-		EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
-		return -EFSCORRUPTED;
-	}
-
 	ix->ei_block = cpu_to_le32(logical);
 	ext4_idx_store_pblock(ix, ptr);
 	le16_add_cpu(&curp->p_hdr->eh_entries, 1);