From 2fe664f1fcf7c4da6891f95708a7a56d3c024354 Mon Sep 17 00:00:00 2001 From: Douglas Caetano dos Santos Date: Thu, 22 Sep 2016 15:52:04 -0300 Subject: tcp: fix wrong checksum calculation on MTU probing 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 --- net/ipv4/tcp_output.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 5288cec..d48d557 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1966,12 +1966,14 @@ static int tcp_mtu_probe(struct sock *sk) len = 0; tcp_for_write_queue_from_safe(skb, next, sk) { copy = min_t(int, skb->len, probe_size - len); - if (nskb->ip_summed) + if (nskb->ip_summed) { skb_copy_bits(skb, 0, skb_put(nskb, copy), copy); - else - nskb->csum = skb_copy_and_csum_bits(skb, 0, - skb_put(nskb, copy), - copy, nskb->csum); + } else { + __wsum csum = skb_copy_and_csum_bits(skb, 0, + skb_put(nskb, copy), + copy, 0); + nskb->csum = csum_block_add(nskb->csum, csum, len); + } if (skb->len <= copy) { /* We've eaten all the data from this skb. -- cgit v1.1 From 019b1c9fe32a2a32c1153e31375f87ec3e591273 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 22 Sep 2016 17:54:00 -0700 Subject: tcp: fix a compile error in DBGUNDO() 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 --- net/ipv4/tcp_input.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 08323bd..a756b87 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2329,10 +2329,9 @@ static void DBGUNDO(struct sock *sk, const char *msg) } #if IS_ENABLED(CONFIG_IPV6) else if (sk->sk_family == AF_INET6) { - struct ipv6_pinfo *np = inet6_sk(sk); pr_debug("Undo %s %pI6/%u c%u l%u ss%u/%u p%u\n", msg, - &np->daddr, ntohs(inet->inet_dport), + &sk->sk_v6_daddr, ntohs(inet->inet_dport), tp->snd_cwnd, tcp_left_out(tp), tp->snd_ssthresh, tp->prior_ssthresh, tp->packets_out); -- cgit v1.1 From 2cf750704bb6d7ed8c7d732e071dd1bc890ea5e8 Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Sun, 25 Sep 2016 23:08:31 +0200 Subject: ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route 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 --- net/ipv4/ipmr.c | 3 ++- net/ipv4/route.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index a87bcd2..5f006e1 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -2123,7 +2123,7 @@ static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, int ipmr_get_route(struct net *net, struct sk_buff *skb, __be32 saddr, __be32 daddr, - struct rtmsg *rtm, int nowait) + struct rtmsg *rtm, int nowait, u32 portid) { struct mfc_cache *cache; struct mr_table *mrt; @@ -2168,6 +2168,7 @@ int ipmr_get_route(struct net *net, struct sk_buff *skb, return -ENOMEM; } + NETLINK_CB(skb2).portid = portid; skb_push(skb2, sizeof(struct iphdr)); skb_reset_network_header(skb2); iph = ip_hdr(skb2); diff --git a/net/ipv4/route.c b/net/ipv4/route.c index b5b47a2..62c3ed0 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2503,7 +2503,8 @@ static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 table_id, IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { int err = ipmr_get_route(net, skb, fl4->saddr, fl4->daddr, - r, nowait); + r, nowait, portid); + if (err <= 0) { if (!nowait) { if (err == 0) -- cgit v1.1