[PATCH AUTOSEL 4.19 16/21] jfs: add a check to prevent array-index-out-of-bounds in dbAdjTree

Sasha Levin
2024-11-24T13:57:44Z

From: Nihar Chaithanya <niharchaithanya@gmail.com>

[ Upstream commit a174706ba4dad895c40b1d2277bade16dfacdcd9 ]

When the value of lp is 0 at the beginning of the for loop, it will
become negative in the next assignment and we should bail out.

Reported-by: syzbot+412dea214d8baa3f7483@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=412dea214d8baa3f7483
Tested-by: syzbot+412dea214d8baa3f7483@syzkaller.appspotmail.com
Signed-off-by: Nihar Chaithanya <niharchaithanya@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/jfs/jfs_dmap.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 7bb2d0212c90a..7e1cc0e21eff2 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -2966,6 +2966,9 @@ static void dbAdjTree(dmtree_t *tp, int leafno, int newval, bool is_ctl)
/* bubble the new value up the tree as required.
*/
for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) {
+ if (lp == 0)
+ break;
+
/* get the index of the first leaf of the 4 leaf
* group containing the specified leaf (leafno).
*/
--
2.43.0