user/sven/linux.git/net/core, branch v3.18.67

net: avoid skb_warn_bad_offload false positives on UFO

2017-08-13T02:24:19Z

[ Upstream commit 8d63bee643f1fb53e472f0e135cae4eb99d62d19 ] skb_warn_bad_offload triggers a warning when an skb enters the GSO stack at __skb_gso_segment that does not have CHECKSUM_PARTIAL checksum offload set. Commit b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise") observed that SKB_GSO_DODGY producers can trigger the check and that passing those packets through the GSO handlers will fix it up. But, the software UFO handler will set ip_summed to CHECKSUM_NONE. When __skb_gso_segment is called from the receive path, this triggers the warning again. Make UFO set CHECKSUM_UNNECESSARY instead of CHECKSUM_NONE. On Tx these two are equivalent. On Rx, this better matches the skb state (checksum computed), as CHECKSUM_NONE here means no checksum computed. See also this thread for context: http://patchwork.ozlabs.org/patch/799015/ Fixes: b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise") Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

rtnetlink: allocate more memory for dev_set_mac_address()

2017-08-11T16:30:14Z

[ Upstream commit 153711f9421be5dbc973dc57a4109dc9d54c89b1 ] virtnet_set_mac_address() interprets mac address as struct sockaddr, but upper layer only allocates dev->addr_len which is ETH_ALEN + sizeof(sa_family_t) in this case. We lack a unified definition for mac address, so just fix the upper layer, this also allows drivers to interpret it to struct sockaddr freely. Reported-by: David Ahern Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: Zero terminate ifr_name in dev_ifname().

2017-08-11T16:30:14Z

[ Upstream commit 63679112c536289826fec61c917621de95ba2ade ] The ifr.ifr_name is passed around and assumed to be NULL terminated. Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: skb_needs_check() accepts CHECKSUM_NONE for tx

2017-08-11T16:30:11Z

commit 6e7bc478c9a006c701c14476ec9d389a484b4864 upstream. My recent change missed fact that UFO would perform a complete UDP checksum before segmenting in frags. In this case skb->ip_summed is set to CHECKSUM_NONE. We need to add this valid case to skb_needs_check() Fixes: b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise") Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: reduce skb_warn_bad_offload() noise

2017-08-11T16:30:08Z

commit b2504a5dbef3305ef41988ad270b0e8ec289331c upstream. Dmitry reported warnings occurring in __skb_gso_segment() [1] All SKB_GSO_DODGY producers can allow user space to feed packets that trigger the current check. We could prevent them from doing so, rejecting packets, but this might add regressions to existing programs. It turns out our SKB_GSO_DODGY handlers properly set up checksum information that is needed anyway when packets needs to be segmented. By checking again skb_needs_check() after skb_mac_gso_segment(), we should remove these pesky warnings, at a very minor cost. With help from Willem de Bruijn [1] WARNING: CPU: 1 PID: 6768 at net/core/dev.c:2439 skb_warn_bad_offload+0x2af/0x390 net/core/dev.c:2434 lo: caps=(0x000000a2803b7c69, 0x0000000000000000) len=138 data_len=0 gso_size=15883 gso_type=4 ip_summed=0 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 6768 Comm: syz-executor1 Not tainted 4.9.0 #5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801c063ecd8 ffffffff82346bdf ffffffff00000001 1ffff100380c7d2e ffffed00380c7d26 0000000041b58ab3 ffffffff84b37e38 ffffffff823468f1 ffffffff84820740 ffffffff84f289c0 dffffc0000000000 ffff8801c063ee20 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0x2ee/0x3ef lib/dump_stack.c:51 [] panic+0x1fb/0x412 kernel/panic.c:179 [] __warn+0x1c4/0x1e0 kernel/panic.c:542 [] warn_slowpath_fmt+0xc5/0x100 kernel/panic.c:565 [] skb_warn_bad_offload+0x2af/0x390 net/core/dev.c:2434 [] __skb_gso_segment+0x482/0x780 net/core/dev.c:2706 [] skb_gso_segment include/linux/netdevice.h:3985 [inline] [] validate_xmit_skb+0x5c9/0xc20 net/core/dev.c:2969 [] __dev_queue_xmit+0xe6b/0x1e70 net/core/dev.c:3383 [] dev_queue_xmit+0x17/0x20 net/core/dev.c:3424 [] packet_snd net/packet/af_packet.c:2930 [inline] [] packet_sendmsg+0x32ed/0x4d30 net/packet/af_packet.c:2955 [] sock_sendmsg_nosec net/socket.c:621 [inline] [] sock_sendmsg+0xca/0x110 net/socket.c:631 [] ___sys_sendmsg+0x8fa/0x9f0 net/socket.c:1954 [] __sys_sendmsg+0x138/0x300 net/socket.c:1988 [] SYSC_sendmsg net/socket.c:1999 [inline] [] SyS_sendmsg+0x2d/0x50 net/socket.c:1995 [] entry_SYSCALL_64_fastpath+0x1f/0xc2 Signed-off-by: Eric Dumazet Reported-by: Dmitry Vyukov Cc: Willem de Bruijn Signed-off-by: David S. Miller Cc: Mark Salyzyn Signed-off-by: Greg Kroah-Hartman

net: prevent sign extension in dev_get_stats()

2017-07-21T06:12:21Z

commit 6f64ec74515925cced6df4571638b5a099a49aae upstream. Similar to the fix provided by Dominik Heidler in commit 9b3dc0a17d73 ("l2tp: cast l2tp traffic counter to unsigned") we need to take care of 32bit kernels in dev_get_stats(). When using atomic_long_read(), we add a 'long' to u64 and might misinterpret high order bit, unless we cast to unsigned. Fixes: caf586e5f23ce ("net: add a core netdev->rx_dropped counter") Fixes: 015f0688f57ca ("net: net: add a core netdev->tx_dropped counter") Fixes: 6e7333d315a76 ("net: add rx_nohandler stat counter") Signed-off-by: Eric Dumazet Cc: Jarod Wilson Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

Fix an intermittent pr_emerg warning about lo becoming free.

2017-07-05T12:35:12Z

[ Upstream commit f186ce61bb8235d80068c390dc2aad7ca427a4c2 ] It looks like this: Message from syslogd@flamingo at Apr 26 00:45:00 ... kernel:unregister_netdevice: waiting for lo to become free. Usage count = 4 They seem to coincide with net namespace teardown. The message is emitted by netdev_wait_allrefs(). Forced a kdump in netdev_run_todo, but found that the refcount on the lo device was already 0 at the time we got to the panic. Used bcc to check the blocking in netdev_run_todo. The only places where we're off cpu there are in the rcu_barrier() and msleep() calls. That behavior is expected. The msleep time coincides with the amount of time we spend waiting for the refcount to reach zero; the rcu_barrier() wait times are not excessive. After looking through the list of callbacks that the netdevice notifiers invoke in this path, it appears that the dst_dev_event is the most interesting. The dst_ifdown path places a hold on the loopback_dev as part of releasing the dev associated with the original dst cache entry. Most of our notifier callbacks are straight-forward, but this one a) looks complex, and b) places a hold on the network interface in question. I constructed a new bcc script that watches various events in the liftime of a dst cache entry. Note that dst_ifdown will take a hold on the loopback device until the invalidated dst entry gets freed. [ __dst_free] on DST: ffff883ccabb7900 IF tap1008300eth0 invoked at 1282115677036183 __dst_free rcu_nocb_kthread kthread ret_from_fork Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: don't call strlen on non-terminated string in dev_set_alias()

2017-07-05T12:35:12Z

[ Upstream commit c28294b941232931fbd714099798eb7aa7e865d7 ] KMSAN reported a use of uninitialized memory in dev_set_alias(), which was caused by calling strlcpy() (which in turn called strlen()) on the user-supplied non-terminated string. Signed-off-by: Alexander Potapenko Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

netem: fix skb_orphan_partial()

2017-06-07T10:01:50Z

commit f6ba8d33cfbb46df569972e64dbb5bb7e929bfd9 upstream. I should have known that lowering skb->truesize was dangerous :/ In case packets are not leaving the host via a standard Ethernet device, but looped back to local sockets, bad things can happen, as reported by Michael Madsen ( https://bugzilla.kernel.org/show_bug.cgi?id=195713 ) So instead of tweaking skb->truesize, lets change skb->destructor and keep a reference on the owner socket via its sk_refcnt. Fixes: f2f872f9272a ("netem: Introduce skb_orphan_partial() helper") Signed-off-by: Eric Dumazet Reported-by: Michael Madsen Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: avoid signed overflows for SO_{SND|RCV}BUFFORCE

2017-05-08T05:44:10Z

commit b98b0bc8c431e3ceb4b26b0dfc8db509518fb290 upstream. CAP_NET_ADMIN users should not be allowed to set negative sk_sndbuf or sk_rcvbuf values, as it can lead to various memory corruptions, crashes, OOM... Note that before commit 82981930125a ("net: cleanups in sock_setsockopt()"), the bug was even more serious, since SO_SNDBUF and SO_RCVBUF were vulnerable. This needs to be backported to all known linux kernels. Again, many thanks to syzkaller team for discovering this gem. Signed-off-by: Eric Dumazet Reported-by: Andrey Konovalov Signed-off-by: David S. Miller Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman