[PATCH] jfs: fix slab-out-of-bounds Read in dtSearch

[Manas Ghandat]

Currently while searching for current page in the sorted entry table
of the page there is a out of bound access. Added a bound check to fix
the error.

Reported-by: syzbot+9924e2a08d9ba0fd4ce2@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: https://syzkaller.appspot.com/bug?extid=9924e2a08d9ba0fd4ce2
Signed-off-by: Manas Ghandat <ghandatmanas@xxxxxxxxx>
---
 fs/jfs/jfs_dtree.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/jfs/jfs_dtree.c b/fs/jfs/jfs_dtree.c
index 92b7c533407c..cf67d32d5b7f 100644
--- a/fs/jfs/jfs_dtree.c
+++ b/fs/jfs/jfs_dtree.c
@@ -633,6 +633,9 @@ int dtSearch(struct inode *ip, struct component_name * key, ino_t * data,
 		for (base = 0, lim = p->header.nextindex; lim; lim >>= 1) {
 			index = base + (lim >> 1);
 
+			if (stbl[index] > 128 || stbl[index] < 0)
+				goto out;
+
 			if (p->header.flag & BT_LEAF) {
 				/* uppercase leaf name to compare */
 				cmp =
-- 
2.37.2