| Message ID | 1520268663.109662.5.camel@gmail.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] ieee802154: 6lowpan: fix possible NULL deref in lowpan_device_event() | expand |
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Mon, 05 Mar 2018 08:51:03 -0800 > From: Eric Dumazet <edumazet@google.com> > > A tun device type can trivially be set to arbitrary value using > TUNSETLINK ioctl(). > > Therefore, lowpan_device_event() must really check that ieee802154_ptr > is not NULL. > > Fixes: 2c88b5283f60d ("ieee802154: 6lowpan: remove check on null") > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Alexander Aring <alex.aring@gmail.com> > Cc: Stefan Schmidt <stefan@osg.samsung.com> > Reported-by: syzbot <syzkaller@googlegroups.com> Adding linux-wpan list. > --- > net/ieee802154/6lowpan/core.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c > index 974765b7d92a..e9f0489e4229 100644 > --- a/net/ieee802154/6lowpan/core.c > +++ b/net/ieee802154/6lowpan/core.c > @@ -206,9 +206,13 @@ static inline void lowpan_netlink_fini(void) > static int lowpan_device_event(struct notifier_block *unused, > unsigned long event, void *ptr) > { > - struct net_device *wdev = netdev_notifier_info_to_dev(ptr); > + struct net_device *ndev = netdev_notifier_info_to_dev(ptr); > + struct wpan_dev *wpan_dev; > > - if (wdev->type != ARPHRD_IEEE802154) > + if (ndev->type != ARPHRD_IEEE802154) > + return NOTIFY_DONE; > + wpan_dev = ndev->ieee802154_ptr; > + if (!wpan_dev) > return NOTIFY_DONE; > > switch (event) { > @@ -217,8 +221,8 @@ static int lowpan_device_event(struct notifier_block *unused, > * also delete possible lowpan interfaces which belongs > * to the wpan interface. > */ > - if (wdev->ieee802154_ptr->lowpan_dev) > - lowpan_dellink(wdev->ieee802154_ptr->lowpan_dev, NULL); > + if (wpan_dev->lowpan_dev) > + lowpan_dellink(wpan_dev->lowpan_dev, NULL); > break; > default: > return NOTIFY_DONE; >
Hello. On 03/05/2018 05:51 PM, Eric Dumazet wrote: > From: Eric Dumazet <edumazet@google.com> > > A tun device type can trivially be set to arbitrary value using > TUNSETLINK ioctl(). > > Therefore, lowpan_device_event() must really check that ieee802154_ptr > is not NULL. > > Fixes: 2c88b5283f60d ("ieee802154: 6lowpan: remove check on null") > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Alexander Aring <alex.aring@gmail.com> > Cc: Stefan Schmidt <stefan@osg.samsung.com> > Reported-by: syzbot <syzkaller@googlegroups.com> > --- > net/ieee802154/6lowpan/core.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c > index 974765b7d92a..e9f0489e4229 100644 > --- a/net/ieee802154/6lowpan/core.c > +++ b/net/ieee802154/6lowpan/core.c > @@ -206,9 +206,13 @@ static inline void lowpan_netlink_fini(void) > static int lowpan_device_event(struct notifier_block *unused, > unsigned long event, void *ptr) > { > - struct net_device *wdev = netdev_notifier_info_to_dev(ptr); > + struct net_device *ndev = netdev_notifier_info_to_dev(ptr); Not sure why you think there is a rename from wdev to ndev necessary. I see this more of a rolled in cosmetic change, but its not a real problem from my side. > + struct wpan_dev *wpan_dev; > > - if (wdev->type != ARPHRD_IEEE802154) > + if (ndev->type != ARPHRD_IEEE802154) > + return NOTIFY_DONE; > + wpan_dev = ndev->ieee802154_ptr; > + if (!wpan_dev) > return NOTIFY_DONE; > > switch (event) { > @@ -217,8 +221,8 @@ static int lowpan_device_event(struct notifier_block *unused, > * also delete possible lowpan interfaces which belongs > * to the wpan interface. > */ > - if (wdev->ieee802154_ptr->lowpan_dev) > - lowpan_dellink(wdev->ieee802154_ptr->lowpan_dev, NULL); > + if (wpan_dev->lowpan_dev) > + lowpan_dellink(wpan_dev->lowpan_dev, NULL); > break; > default: > return NOTIFY_DONE; > Thanks a lot for fixing this and syzbot for finding it. Acked-by: Stefan Schmidt <stefan@osg.samsung.com> Dave, could you take this one directly? I have no other patches pending for your net tree (only net-next) and having a pull request for just this patch does not make much sense. regards Stefan Schmidt
Hello Dave. On 03/06/2018 01:56 PM, Stefan Schmidt wrote: > Hello. > > > On 03/05/2018 05:51 PM, Eric Dumazet wrote: >> From: Eric Dumazet <edumazet@google.com> >> >> A tun device type can trivially be set to arbitrary value using >> TUNSETLINK ioctl(). >> >> Therefore, lowpan_device_event() must really check that ieee802154_ptr >> is not NULL. >> >> Fixes: 2c88b5283f60d ("ieee802154: 6lowpan: remove check on null") >> Signed-off-by: Eric Dumazet <edumazet@google.com> >> Cc: Alexander Aring <alex.aring@gmail.com> >> Cc: Stefan Schmidt <stefan@osg.samsung.com> >> Reported-by: syzbot <syzkaller@googlegroups.com> >> --- >> net/ieee802154/6lowpan/core.c | 12 ++++++++---- >> 1 file changed, 8 insertions(+), 4 deletions(-) >> >> diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c >> index 974765b7d92a..e9f0489e4229 100644 >> --- a/net/ieee802154/6lowpan/core.c >> +++ b/net/ieee802154/6lowpan/core.c >> @@ -206,9 +206,13 @@ static inline void lowpan_netlink_fini(void) >> static int lowpan_device_event(struct notifier_block *unused, >> unsigned long event, void *ptr) >> { >> - struct net_device *wdev = netdev_notifier_info_to_dev(ptr); >> + struct net_device *ndev = netdev_notifier_info_to_dev(ptr); > Not sure why you think there is a rename from wdev to ndev necessary. > I see this more of a rolled in cosmetic change, but its not a real problem from my side. > >> + struct wpan_dev *wpan_dev; >> >> - if (wdev->type != ARPHRD_IEEE802154) >> + if (ndev->type != ARPHRD_IEEE802154) >> + return NOTIFY_DONE; >> + wpan_dev = ndev->ieee802154_ptr; >> + if (!wpan_dev) >> return NOTIFY_DONE; >> >> switch (event) { >> @@ -217,8 +221,8 @@ static int lowpan_device_event(struct notifier_block *unused, >> * also delete possible lowpan interfaces which belongs >> * to the wpan interface. >> */ >> - if (wdev->ieee802154_ptr->lowpan_dev) >> - lowpan_dellink(wdev->ieee802154_ptr->lowpan_dev, NULL); >> + if (wpan_dev->lowpan_dev) >> + lowpan_dellink(wpan_dev->lowpan_dev, NULL); >> break; >> default: >> return NOTIFY_DONE; >> > Thanks a lot for fixing this and syzbot for finding it. > > > Acked-by: Stefan Schmidt <stefan@osg.samsung.com> > > Dave, could you take this one directly? I have no other patches pending for your net tree (only net-next) and having a pull request for just > this patch does not make much sense. > Did you miss this or would you prefer if I do a pull request for this single patch? Either way would be fine with me. regards Stefan Schmidt
From: Stefan Schmidt <stefan@osg.samsung.com> Date: Thu, 8 Mar 2018 17:21:49 +0100 > Did you miss this or would you prefer if I do a pull request for > this single patch? Either way would be fine with me. Sorry, this escaped me. Applied and queued up for -stable, thanks.
diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c index 974765b7d92a..e9f0489e4229 100644 --- a/net/ieee802154/6lowpan/core.c +++ b/net/ieee802154/6lowpan/core.c @@ -206,9 +206,13 @@ static inline void lowpan_netlink_fini(void) static int lowpan_device_event(struct notifier_block *unused, unsigned long event, void *ptr) { - struct net_device *wdev = netdev_notifier_info_to_dev(ptr); + struct net_device *ndev = netdev_notifier_info_to_dev(ptr); + struct wpan_dev *wpan_dev; - if (wdev->type != ARPHRD_IEEE802154) + if (ndev->type != ARPHRD_IEEE802154) + return NOTIFY_DONE; + wpan_dev = ndev->ieee802154_ptr; + if (!wpan_dev) return NOTIFY_DONE; switch (event) { @@ -217,8 +221,8 @@ static int lowpan_device_event(struct notifier_block *unused, * also delete possible lowpan interfaces which belongs * to the wpan interface. */ - if (wdev->ieee802154_ptr->lowpan_dev) - lowpan_dellink(wdev->ieee802154_ptr->lowpan_dev, NULL); + if (wpan_dev->lowpan_dev) + lowpan_dellink(wpan_dev->lowpan_dev, NULL); break; default: return NOTIFY_DONE;