[PATCH AUTOSEL 5.10 20/33] jfs: array-index-out-of-bounds fix in dtReadFirst

Sasha Levin
2024-11-24T13:54:50Z

From: Ghanshyam Agrawal <ghanshyam1898@gmail.com>

[ Upstream commit ca84a2c9be482836b86d780244f0357e5a778c46 ]

The value of stbl can be sometimes out of bounds due
to a bad filesystem. Added a check with appopriate return
of error code in that case.

Reported-by: syzbot+65fa06e29859e41a83f3@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=65fa06e29859e41a83f3
Signed-off-by: Ghanshyam Agrawal <ghanshyam1898@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/jfs/jfs_dtree.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/fs/jfs/jfs_dtree.c b/fs/jfs/jfs_dtree.c
index a222a9d71887f..8f7ce1bea44c5 100644
--- a/fs/jfs/jfs_dtree.c
+++ b/fs/jfs/jfs_dtree.c
@@ -3382,6 +3382,13 @@ static int dtReadFirst(struct inode *ip, struct btstack * btstack)

/* get the leftmost entry */
stbl = DT_GETSTBL(p);
+
+ if (stbl[0] < 0 || stbl[0] > 127) {
+ DT_PUTPAGE(mp);
+ jfs_error(ip->i_sb, "stbl[0] out of bound\n");
+ return -EIO;
+ }
+
xd = (pxd_t *) & p->slot[stbl[0]];

/* get the child page block address */
--
2.43.0