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authorYing Xue <ying.xue@windriver.com>2019-01-14 17:22:24 +0800
committerDavid S. Miller <davem@davemloft.net>2019-01-15 20:29:20 -0800
commita88289f4ddee4165d5f796bd99e09eec3133c16b (patch)
tree509473bb1f9496c9be9c0d57974a64873f8ec39c
parentd62f38c295e56147e8298af1e0e0ec9e7cc14937 (diff)
downloadlinux-a88289f4ddee4165d5f796bd99e09eec3133c16b.tar.bz2
tipc: fix uninit-value in in tipc_conn_rcv_sub
syzbot reported: BUG: KMSAN: uninit-value in tipc_conn_rcv_sub+0x184/0x950 net/tipc/topsrv.c:373 CPU: 0 PID: 66 Comm: kworker/u4:4 Not tainted 4.17.0-rc3+ #88 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: tipc_rcv tipc_conn_recv_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:113 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683 tipc_conn_rcv_sub+0x184/0x950 net/tipc/topsrv.c:373 tipc_conn_rcv_from_sock net/tipc/topsrv.c:409 [inline] tipc_conn_recv_work+0x3cd/0x560 net/tipc/topsrv.c:424 process_one_work+0x12c6/0x1f60 kernel/workqueue.c:2145 worker_thread+0x113c/0x24f0 kernel/workqueue.c:2279 kthread+0x539/0x720 kernel/kthread.c:239 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:412 Local variable description: ----s.i@tipc_conn_recv_work Variable was created at: tipc_conn_recv_work+0x65/0x560 net/tipc/topsrv.c:419 process_one_work+0x12c6/0x1f60 kernel/workqueue.c:2145 In tipc_conn_rcv_from_sock(), it always supposes the length of message received from sock_recvmsg() is not smaller than the size of struct tipc_subscr. However, this assumption is false. Especially when the length of received message is shorter than struct tipc_subscr size, we will end up touching uninitialized fields in tipc_conn_rcv_sub(). Reported-by: syzbot+8951a3065ee7fd6d6e23@syzkaller.appspotmail.com Reported-by: syzbot+75e6e042c5bbf691fc82@syzkaller.appspotmail.com Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/tipc/topsrv.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/tipc/topsrv.c b/net/tipc/topsrv.c
index efb16f69bd2c..a457c0fbbef1 100644
--- a/net/tipc/topsrv.c
+++ b/net/tipc/topsrv.c
@@ -398,7 +398,7 @@ static int tipc_conn_rcv_from_sock(struct tipc_conn *con)
ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT);
if (ret == -EWOULDBLOCK)
return -EWOULDBLOCK;
- if (ret > 0) {
+ if (ret == sizeof(s)) {
read_lock_bh(&sk->sk_callback_lock);
ret = tipc_conn_rcv_sub(srv, con, &s);
read_unlock_bh(&sk->sk_callback_lock);