1From 508b1b57f73a49effc975731f8b76325d45b0e0f Mon Sep 17 00:00:00 2001
2From: zhanchengbin <zhanchengbin1@huawei.com>
3Date: Fri, 18 Mar 2022 00:02:50 +0800
4Subject: [PATCH] e2fsck: handle->level is overflow in ext2fs_extent_get.
5
6In function check_blocks_extents, program call scan_extent_node recursively until
7leaf extent is found, and if this leaf extent is the last one in this extent_idx,
8it will delete the parent extent_idx of this leaf extent in ext2fs_extent_delete,
9and do handle->level--. After scan_extent_node return, program allways to get up extent,
10but level was already decreased.
11So calling ext2fs_extent_get(EXT2_EXTENT_UP) again will return EXT2_ET_EXTENT_NO_UP,
12and then print failed. 
13
14Signed-off-by: zhanchengbin <zhanchengbin1@huawei.com>
15---
16 e2fsck/pass1.c      | 7 +++++++
17 lib/ext2fs/ext2fs.h | 1 +
18 lib/ext2fs/extent.c | 5 +++++
19 3 files changed, 13 insertions(+)
20
21diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
22index 26b9ab71..3d698934 100644
23--- a/e2fsck/pass1.c
24+++ b/e2fsck/pass1.c
25@@ -3074,11 +3074,18 @@ report_problem:
26 					}
27 				}
28 			}
29+
30+			int level_bak = ext2fs_current_level_get(ehandle);
31+
32 			scan_extent_node(ctx, pctx, pb, extent.e_lblk,
33 					 last_lblk, eof_block, ehandle,
34 					 next_try_repairs);
35 			if (pctx->errcode)
36 				return;
37+
38+			if (level_bak != ext2fs_current_level_get(ehandle))
39+				return;
40+
41 			pctx->errcode = ext2fs_extent_get(ehandle,
42 						  EXT2_EXTENT_UP, &extent);
43 			if (pctx->errcode) {
44diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
45index 68f9c1fe..d0468f11 100644
46--- a/lib/ext2fs/ext2fs.h
47+++ b/lib/ext2fs/ext2fs.h
48@@ -1333,6 +1333,7 @@ extern errcode_t ext2fs_extent_open2(ext2_filsys fs, ext2_ino_t ino,
49 extern void ext2fs_extent_free(ext2_extent_handle_t handle);
50 extern errcode_t ext2fs_extent_get(ext2_extent_handle_t handle,
51 				   int flags, struct ext2fs_extent *extent);
52+extern int ext2fs_current_level_get(ext2_extent_handle_t handle);
53 extern errcode_t ext2fs_extent_node_split(ext2_extent_handle_t handle);
54 extern errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle, int flags,
55 				       struct ext2fs_extent *extent);
56diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c
57index b324c7b0..07acd4e0 100644
58--- a/lib/ext2fs/extent.c
59+++ b/lib/ext2fs/extent.c
60@@ -575,6 +575,11 @@ retry:
61 	return 0;
62 }
63 
64+int ext2fs_current_level_get(ext2_extent_handle_t handle)
65+{
66+	return handle->level;
67+}
68+
69 static errcode_t update_path(ext2_extent_handle_t handle)
70 {
71 	blk64_t				blk;
72-- 
732.27.0
74
75