Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Siddh Raman Pant <code@siddh.me>
To:     code@siddh.me
Cc:     david@fromorbit.com, djwong@kernel.org, fgheet255t@gmail.com,
        hch@infradead.org, linux-ext4@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-xfs@vger.kernel.org, riteshh@linux.ibm.com,
        syzbot+a8e049cd3abd342936b6@syzkaller.appspotmail.com,
        syzkaller-bugs@googlegroups.com, willy@infradead.org
Message-ID: <20220821114816.24193-1-code@siddh.me>
Subject: Re: [syzbot] WARNING in iomap_iter
Date:   Sun, 21 Aug 2022 17:18:16 +0530
In-Reply-To: <182c028abf0.2dc6f7c973088.2963173753499991828@siddh.me>
References: <182c028abf0.2dc6f7c973088.2963173753499991828@siddh.me>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain; charset=utf8
Precedence: bulk

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.gi=
t master

---
 drivers/block/loop.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index e3c0ba93c1a3..a3d9af0a2077 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -979,9 +979,15 @@ loop_set_status_from_info(struct loop_device *lo,
=20
 =09lo->lo_offset =3D info->lo_offset;
 =09lo->lo_sizelimit =3D info->lo_sizelimit;
+=09lo->lo_flags =3D info->lo_flags;
+
+=09/* loff_t/int vars are assigned __u64/__u32 vars (respectively) */
+=09if (lo->lo_offset < 0 || lo->lo_sizelimit < 0 || lo->lo_flags < 0)
+=09=09return -EOVERFLOW;
+
 =09memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE);
 =09lo->lo_file_name[LO_NAME_SIZE-1] =3D 0;
-=09lo->lo_flags =3D info->lo_flags;
+
 =09return 0;
 }
=20
--=20
2.35.1