From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Hartkopp Subject: [PATCH] can: fix warning in bcm_connect/proc_register Date: Mon, 24 Oct 2016 21:11:26 +0200 Message-ID: <20161024191126.30256-1-socketcan@hartkopp.net> Cc: linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller@googlegroups.com, kcc@google.com, glider@google.com, dvyukov@google.com, edumazet@google.com, Oliver Hartkopp To: andreyknvl@google.com, xiyou.wangcong@gmail.com, davem@davemloft.net Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Andrey Konovalov reported an issue with proc_register in bcm.c. As suggested by Cong Wang this patch adds a lock_sock() protection and a check for unsuccessful proc_create_data() in bcm_connect(). Reference: http://marc.info/?l=linux-netdev&m=147732648731237 Reported-by: Andrey Konovalov Suggested-by: Cong Wang Signed-off-by: Oliver Hartkopp --- net/can/bcm.c | 32 +++++++++++++++++++++++--------- 1 file changed, 23 insertions(+), 9 deletions(-) diff --git a/net/can/bcm.c b/net/can/bcm.c index 8e999ff..8af9d25 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -1549,24 +1549,31 @@ static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; struct sock *sk = sock->sk; struct bcm_sock *bo = bcm_sk(sk); + int ret = 0; if (len < sizeof(*addr)) return -EINVAL; - if (bo->bound) - return -EISCONN; + lock_sock(sk); + + if (bo->bound) { + ret = -EISCONN; + goto fail; + } /* bind a device to this socket */ if (addr->can_ifindex) { struct net_device *dev; dev = dev_get_by_index(&init_net, addr->can_ifindex); - if (!dev) - return -ENODEV; - + if (!dev) { + ret = -ENODEV; + goto fail; + } if (dev->type != ARPHRD_CAN) { dev_put(dev); - return -ENODEV; + ret = -ENODEV; + goto fail; } bo->ifindex = dev->ifindex; @@ -1577,17 +1584,24 @@ static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, bo->ifindex = 0; } - bo->bound = 1; - if (proc_dir) { /* unique socket address as filename */ sprintf(bo->procname, "%lu", sock_i_ino(sk)); bo->bcm_proc_read = proc_create_data(bo->procname, 0644, proc_dir, &bcm_proc_fops, sk); + if (!bo->bcm_proc_read) { + ret = -ENOMEM; + goto fail; + } } - return 0; + bo->bound = 1; + +fail: + release_sock(sk); + + return ret; } static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, -- 2.9.3