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| author | Ziyang Xuan <william.xuanziyang@huawei.com> | 2021-07-15 20:22:04 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-07-15 11:08:33 -0700 |
| commit | 991e634360f2622a683b48dfe44fe6d9cb765a09 (patch) | |
| tree | 4158879939e7e2e55a5f555086493a10d8f20e52 /net/caif | |
| parent | 70713dddf3d25a02d1952f8c5d2688c986d2f2fb (diff) | |
| download | lwn-991e634360f2622a683b48dfe44fe6d9cb765a09.tar.gz lwn-991e634360f2622a683b48dfe44fe6d9cb765a09.zip | |
net: fix uninit-value in caif_seqpkt_sendmsg
When nr_segs equal to zero in iovec_from_user, the object
msg->msg_iter.iov is uninit stack memory in caif_seqpkt_sendmsg
which is defined in ___sys_sendmsg. So we cann't just judge
msg->msg_iter.iov->base directlly. We can use nr_segs to judge
msg in caif_seqpkt_sendmsg whether has data buffers.
=====================================================
BUG: KMSAN: uninit-value in caif_seqpkt_sendmsg+0x693/0xf60 net/caif/caif_socket.c:542
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c9/0x220 lib/dump_stack.c:118
kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
__msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
caif_seqpkt_sendmsg+0x693/0xf60 net/caif/caif_socket.c:542
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg net/socket.c:672 [inline]
____sys_sendmsg+0x12b6/0x1350 net/socket.c:2343
___sys_sendmsg net/socket.c:2397 [inline]
__sys_sendmmsg+0x808/0xc90 net/socket.c:2480
__compat_sys_sendmmsg net/compat.c:656 [inline]
Reported-by: syzbot+09a5d591c1f98cf5efcb@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=1ace85e8fc9b0d5a45c08c2656c3e91762daa9b8
Fixes: bece7b2398d0 ("caif: Rewritten socket implementation")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/caif')
| -rw-r--r-- | net/caif/caif_socket.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c index 647554c9813b..e12fd3cad619 100644 --- a/net/caif/caif_socket.c +++ b/net/caif/caif_socket.c @@ -539,7 +539,8 @@ static int caif_seqpkt_sendmsg(struct socket *sock, struct msghdr *msg, goto err; ret = -EINVAL; - if (unlikely(msg->msg_iter.iov->iov_base == NULL)) + if (unlikely(msg->msg_iter.nr_segs == 0) || + unlikely(msg->msg_iter.iov->iov_base == NULL)) goto err; noblock = msg->msg_flags & MSG_DONTWAIT; |