Merge tag 'ext4_for_linus_stable2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 fixes from Ted Ts'o:
 "Fix a regression in the lazytime code that was introduced in v6.1-rc1,
  and a use-after-free that can be triggered by a maliciously corrupted
  file system"

* tag 'ext4_for_linus_stable2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  fs: do not update freeing inode i_io_list
  ext4: fix use-after-free in ext4_ext_shift_extents

fs/ext4/extents.c

@@ -5184,6 +5184,7 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
 	 * and it is decreased till we reach start.
 	 */
 again:
+	ret = 0;
 	if (SHIFT == SHIFT_LEFT)
 		iterator = &start;
 	else
@@ -5227,14 +5228,21 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
 					ext4_ext_get_actual_len(extent);
 		} else {
 			extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
-			if (le32_to_cpu(extent->ee_block) > 0)
+			if (le32_to_cpu(extent->ee_block) > start)
 				*iterator = le32_to_cpu(extent->ee_block) - 1;
-			else
-				/* Beginning is reached, end of the loop */
+			else if (le32_to_cpu(extent->ee_block) == start)
 				iterator = NULL;
-			/* Update path extent in case we need to stop */
-			while (le32_to_cpu(extent->ee_block) < start)
+			else {
+				extent = EXT_LAST_EXTENT(path[depth].p_hdr);
+				while (le32_to_cpu(extent->ee_block) >= start)
+					extent--;
+
+				if (extent == EXT_LAST_EXTENT(path[depth].p_hdr))
+					break;
+
 				extent++;
+				iterator = NULL;
+			}
 			path[depth].p_ext = extent;
 		}
 		ret = ext4_ext_shift_path_extents(path, shift, inode,

fs/fs-writeback.c

@@ -1712,9 +1712,14 @@ static int writeback_single_inode(struct inode *inode,
 	wb = inode_to_wb_and_lock_list(inode);
 	spin_lock(&inode->i_lock);
 	/*
-	 * If the inode is now fully clean, then it can be safely removed from
-	 * its writeback list (if any).  Otherwise the flusher threads are
-	 * responsible for the writeback lists.
+	 * If the inode is freeing, its i_io_list shoudn't be updated
+	 * as it can be finally deleted at this moment.
+	 */
+	if (!(inode->i_state & I_FREEING)) {
+		/*
+		 * If the inode is now fully clean, then it can be safely
+		 * removed from its writeback list (if any). Otherwise the
+		 * flusher threads are responsible for the writeback lists.
 		 */
 		if (!(inode->i_state & I_DIRTY_ALL))
 			inode_cgwb_move_to_attached(inode, wb);
@@ -1723,7 +1728,10 @@ static int writeback_single_inode(struct inode *inode,
 				redirty_tail_locked(inode, wb);
 			else if (inode->i_state & I_DIRTY_TIME) {
 				inode->dirtied_when = jiffies;
-			inode_io_list_move_locked(inode, wb, &wb->b_dirty_time);
+				inode_io_list_move_locked(inode,
+							  wb,
+							  &wb->b_dirty_time);
+			}
 		}
 	}