From 11eb2645cbf38a08ae491bf6c602eea900ec0bb5 Mon Sep 17 00:00:00 2001 From: Zefan Li Date: Wed, 26 Jun 2013 15:29:54 +0800 Subject: dlci: acquire rtnl_lock before calling __dev_get_by_name() Otherwise the net device returned can be freed at anytime. Signed-off-by: Li Zefan Cc: stable@vger.kernel.org Signed-off-by: David S. Miller --- drivers/net/wan/dlci.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) (limited to 'drivers/net/wan') diff --git a/drivers/net/wan/dlci.c b/drivers/net/wan/dlci.c index 147614ed86aa..1f6e0538c716 100644 --- a/drivers/net/wan/dlci.c +++ b/drivers/net/wan/dlci.c @@ -385,20 +385,24 @@ static int dlci_del(struct dlci_add *dlci) struct net_device *master, *slave; int err; + rtnl_lock(); + /* validate slave device */ master = __dev_get_by_name(&init_net, dlci->devname); - if (!master) - return -ENODEV; + if (!master) { + err = -ENODEV; + goto out; + } if (netif_running(master)) { - return -EBUSY; + err = -EBUSY; + goto out; } dlp = netdev_priv(master); slave = dlp->slave; flp = netdev_priv(slave); - rtnl_lock(); err = (*flp->deassoc)(slave, master); if (!err) { list_del(&dlp->list); @@ -407,8 +411,8 @@ static int dlci_del(struct dlci_add *dlci) dev_put(slave); } +out: rtnl_unlock(); - return err; } -- cgit v1.2.3-59-g8ed1b From 578a1310f2592ba90c5674bca21c1dbd1adf3f0a Mon Sep 17 00:00:00 2001 From: Zefan Li Date: Wed, 26 Jun 2013 15:31:58 +0800 Subject: dlci: validate the net device in dlci_del() We triggered an oops while running trinity with 3.4 kernel: BUG: unable to handle kernel paging request at 0000000100000d07 IP: [] dlci_ioctl+0xd8/0x2d4 [dlci] PGD 640c0d067 PUD 0 Oops: 0000 [#1] PREEMPT SMP CPU 3 ... Pid: 7302, comm: trinity-child3 Not tainted 3.4.24.09+ 40 Huawei Technologies Co., Ltd. Tecal RH2285 /BC11BTSA RIP: 0010:[] [] dlci_ioctl+0xd8/0x2d4 [dlci] ... Call Trace: [] sock_ioctl+0x153/0x280 [] do_vfs_ioctl+0xa4/0x5e0 [] ? fget_light+0x3ea/0x490 [] sys_ioctl+0x4f/0x80 [] system_call_fastpath+0x16/0x1b ... It's because the net device is not a dlci device. Reported-by: Li Jinyue Signed-off-by: Li Zefan Cc: stable@vger.kernel.org Signed-off-by: David S. Miller --- drivers/net/wan/dlci.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/net/wan') diff --git a/drivers/net/wan/dlci.c b/drivers/net/wan/dlci.c index 1f6e0538c716..6a8a382c5f4c 100644 --- a/drivers/net/wan/dlci.c +++ b/drivers/net/wan/dlci.c @@ -384,6 +384,7 @@ static int dlci_del(struct dlci_add *dlci) struct frad_local *flp; struct net_device *master, *slave; int err; + bool found = false; rtnl_lock(); @@ -394,6 +395,17 @@ static int dlci_del(struct dlci_add *dlci) goto out; } + list_for_each_entry(dlp, &dlci_devs, list) { + if (dlp->master == master) { + found = true; + break; + } + } + if (!found) { + err = -ENODEV; + goto out; + } + if (netif_running(master)) { err = -EBUSY; goto out; -- cgit v1.2.3-59-g8ed1b