linux/net/ipv4, branch v4.8

ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route

2016-09-26T03:41:39Z

Since the commit below the ipmr/ip6mr rtnl_unicast() code uses the portid instead of the previous dst_pid which was copied from in_skb's portid. Since the skb is new the portid is 0 at that point so the packets are sent to the kernel and we get scheduling while atomic or a deadlock (depending on where it happens) by trying to acquire rtnl two times. Also since this is RTM_GETROUTE, it can be triggered by a normal user. Here's the sleeping while atomic trace: [ 7858.212557] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620 [ 7858.212748] in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/0 [ 7858.212881] 2 locks held by swapper/0/0: [ 7858.213013] #0: (((&mrt->ipmr_expire_timer))){+.-...}, at: [] call_timer_fn+0x5/0x350 [ 7858.213422] #1: (mfc_unres_lock){+.....}, at: [] ipmr_expire_process+0x25/0x130 [ 7858.213807] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.0-rc7+ #179 [ 7858.213934] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 7858.214108] 0000000000000000 ffff88005b403c50 ffffffff813a7804 0000000000000000 [ 7858.214412] ffffffff81a1338e ffff88005b403c78 ffffffff810a4a72 ffffffff81a1338e [ 7858.214716] 000000000000026c 0000000000000000 ffff88005b403ca8 ffffffff810a4b9f [ 7858.215251] Call Trace: [ 7858.215412] [] dump_stack+0x85/0xc1 [ 7858.215662] [] ___might_sleep+0x192/0x250 [ 7858.215868] [] __might_sleep+0x6f/0x100 [ 7858.216072] [] mutex_lock_nested+0x33/0x4d0 [ 7858.216279] [] ? netlink_lookup+0x25f/0x460 [ 7858.216487] [] rtnetlink_rcv+0x1b/0x40 [ 7858.216687] [] netlink_unicast+0x19c/0x260 [ 7858.216900] [] rtnl_unicast+0x20/0x30 [ 7858.217128] [] ipmr_destroy_unres+0xa9/0xf0 [ 7858.217351] [] ipmr_expire_process+0x8f/0x130 [ 7858.217581] [] ? ipmr_net_init+0x180/0x180 [ 7858.217785] [] ? ipmr_net_init+0x180/0x180 [ 7858.217990] [] call_timer_fn+0xa5/0x350 [ 7858.218192] [] ? call_timer_fn+0x5/0x350 [ 7858.218415] [] ? ipmr_net_init+0x180/0x180 [ 7858.218656] [] run_timer_softirq+0x260/0x640 [ 7858.218865] [] ? __do_softirq+0xbb/0x54f [ 7858.219068] [] __do_softirq+0xe8/0x54f [ 7858.219269] [] irq_exit+0xb8/0xc0 [ 7858.219463] [] smp_apic_timer_interrupt+0x42/0x50 [ 7858.219678] [] apic_timer_interrupt+0x8c/0xa0 [ 7858.219897] [] ? native_safe_halt+0x6/0x10 [ 7858.220165] [] ? trace_hardirqs_on+0xd/0x10 [ 7858.220373] [] default_idle+0x23/0x190 [ 7858.220574] [] arch_cpu_idle+0xf/0x20 [ 7858.220790] [] default_idle_call+0x4c/0x60 [ 7858.221016] [] cpu_startup_entry+0x39b/0x4d0 [ 7858.221257] [] rest_init+0x135/0x140 [ 7858.221469] [] start_kernel+0x50e/0x51b [ 7858.221670] [] ? early_idt_handler_array+0x120/0x120 [ 7858.221894] [] x86_64_start_reservations+0x2a/0x2c [ 7858.222113] [] x86_64_start_kernel+0x13b/0x14a Fixes: 2942e9005056 ("[RTNETLINK]: Use rtnl_unicast() for rtnetlink unicasts") Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

tcp: fix a compile error in DBGUNDO()

2016-09-23T12:26:32Z

If DBGUNDO() is enabled (FASTRETRANS_DEBUG > 1), a compile error will happen, since inet6_sk(sk)->daddr became sk->sk_v6_daddr Fixes: efe4208f47f9 ("ipv6: make lookups simpler and faster") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: fix wrong checksum calculation on MTU probing

2016-09-23T11:55:02Z

With TCP MTU probing enabled and offload TX checksumming disabled, tcp_mtu_probe() calculated the wrong checksum when a fragment being copied into the probe's SKB had an odd length. This was caused by the direct use of skb_copy_and_csum_bits() to calculate the checksum, as it pads the fragment being copied, if needed. When this fragment was not the last, a subsequent call used the previous checksum without considering this padding. The effect was a stale connection in one way, as even retransmissions wouldn't solve the problem, because the checksum was never recalculated for the full SKB length. Signed-off-by: Douglas Caetano dos Santos Signed-off-by: David S. Miller

tcp: properly account Fast Open SYN-ACK retrans

2016-09-22T07:33:01Z

Since the TFO socket is accepted right off SYN-data, the socket owner can call getsockopt(TCP_INFO) to collect ongoing SYN-ACK retransmission or timeout stats (i.e., tcpi_total_retrans, tcpi_retransmits). Currently those stats are only updated upon handshake completes. This patch fixes it. Signed-off-by: Yuchung Cheng Signed-off-by: Eric Dumazet Signed-off-by: Neal Cardwell Signed-off-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller

tcp: fix under-accounting retransmit SNMP counters

2016-09-22T07:33:01Z

This patch fixes these under-accounting SNMP rtx stats LINUX_MIB_TCPFORWARDRETRANS LINUX_MIB_TCPFASTRETRANS LINUX_MIB_TCPSLOWSTARTRETRANS when retransmitting TSO packets Fixes: 10d3be569243 ("tcp-tso: do not split TSO packets at retransmit time") Signed-off-by: Yuchung Cheng Acked-by: Eric Dumazet Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2016-09-22T06:56:23Z

Steffen Klassert says: ==================== pull request (net): ipsec 2016-09-21 1) Propagate errors on security context allocation. From Mathias Krause. 2) Fix inbound policy checks for inter address family tunnels. From Thomas Zeitlhofer. 3) Fix an old memory leak on aead algorithm usage. From Ilan Tayari. 4) A recent patch fixed a possible NULL pointer dereference but broke the vti6 input path. Fix from Nicolas Dichtel. ==================== Signed-off-by: David S. Miller

net: get rid of an signed integer overflow in ip_idents_reserve()

2016-09-22T06:41:17Z

Jiri Pirko reported an UBSAN warning happening in ip_idents_reserve() [] UBSAN: Undefined behaviour in ./arch/x86/include/asm/atomic.h:156:11 [] signed integer overflow: [] -2117905507 + -695755206 cannot be represented in type 'int' Since we do not have uatomic_add_return() yet, use atomic_cmpxchg() so that the arithmetics can be done using unsigned int. Fixes: 04ca6973f7c1 ("ip: make IP identifiers less predictable") Signed-off-by: Eric Dumazet Reported-by: Jiri Pirko Signed-off-by: David S. Miller

ipmr, ip6mr: return lastuse relative to now

2016-09-21T04:58:23Z

When I introduced the lastuse member I made a subtle error because it was returned as an absolute value but that is meaningless to user-space as it doesn't allow to see how old exactly an entry is. Let's make it similar to how the bridge returns such values and make it relative to "now" (jiffies). This allows us to show the actual age of the entries and is much more useful (e.g. user-space daemons can age out entries, iproute2 can display the lastuse properly). Fixes: 43b9e1274060 ("net: ipmr/ip6mr: add support for keeping an entry age") Reported-by: Satish Ashok Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

tcp: fix overflow in __tcp_retransmit_skb()

2016-09-17T13:59:30Z

If a TCP socket gets a large write queue, an overflow can happen in a test in __tcp_retransmit_skb() preventing all retransmits. The flow then stalls and resets after timeouts. Tested: sysctl -w net.core.wmem_max=1000000000 netperf -H dest -- -s 1000000000 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: VRF: Pass original iif to ip_route_input()

2016-09-16T08:24:07Z

The function ip_rcv_finish() calls l3mdev_ip_rcv(). On any VRF except the global VRF, this replaces skb->dev with the VRF master interface. When calling ip_route_input_noref() from here, the checks for forwarding look at this master device instead of the initial ingress interface. This will allow packets to be routed which normally would be dropped. For example, an interface that is not assigned an IP address should drop packets, but because the checking is against the master device, the packet will be forwarded. The fix here is to still call l3mdev_ip_rcv(), but remember the initial net_device. This is passed to the other functions within ip_rcv_finish, so they still see the original interface. Signed-off-by: Mark Tomlinson Acked-by: David Ahern Signed-off-by: David S. Miller