1*4882a593SmuzhiyunFrom ffd5a46f68710e2781899d0be4d701429a5a817d Mon Sep 17 00:00:00 2001
2*4882a593SmuzhiyunFrom: Daniel Axtens <dja@axtens.net>
3*4882a593SmuzhiyunDate: Mon, 18 Jan 2021 14:51:11 +1100
4*4882a593SmuzhiyunSubject: [PATCH] fs/jfs: Do not move to leaf level if name length is negative
5*4882a593Smuzhiyun
6*4882a593SmuzhiyunFuzzing JFS revealed crashes where a negative number would be passed
7*4882a593Smuzhiyunto le_to_cpu16_copy(). There it would be cast to a large positive number
8*4882a593Smuzhiyunand the copy would read and write off the end of the respective buffers.
9*4882a593Smuzhiyun
10*4882a593SmuzhiyunCatch this at the top as well as the bottom of the loop.
11*4882a593Smuzhiyun
12*4882a593SmuzhiyunSigned-off-by: Daniel Axtens <dja@axtens.net>
13*4882a593SmuzhiyunReviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
14*4882a593SmuzhiyunSigned-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
15*4882a593Smuzhiyun---
16*4882a593Smuzhiyun grub-core/fs/jfs.c | 2 +-
17*4882a593Smuzhiyun 1 file changed, 1 insertion(+), 1 deletion(-)
18*4882a593Smuzhiyun
19*4882a593Smuzhiyundiff --git a/grub-core/fs/jfs.c b/grub-core/fs/jfs.c
20*4882a593Smuzhiyunindex d5a6d65..e5bbda6 100644
21*4882a593Smuzhiyun--- a/grub-core/fs/jfs.c
22*4882a593Smuzhiyun+++ b/grub-core/fs/jfs.c
23*4882a593Smuzhiyun@@ -567,7 +567,7 @@ grub_jfs_getent (struct grub_jfs_diropen *diro)
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun   /* Move down to the leaf level.  */
26*4882a593Smuzhiyun   nextent = leaf->next;
27*4882a593Smuzhiyun-  if (leaf->next != 255)
28*4882a593Smuzhiyun+  if (leaf->next != 255 && len > 0)
29*4882a593Smuzhiyun     do
30*4882a593Smuzhiyun       {
31*4882a593Smuzhiyun  	next_leaf = &diro->next_leaf[nextent];
32*4882a593Smuzhiyun--
33*4882a593Smuzhiyun2.14.2
34*4882a593Smuzhiyun
35