From 5d407b071dc369c26a38398326ee2be53651cfe4 Mon Sep 17 00:00:00 2001 From: Taehee Yoo Date: Mon, 10 Sep 2018 02:47:05 +0900 Subject: ip: frags: fix crash in ip_do_fragment() A kernel crash occurrs when defragmented packet is fragmented in ip_do_fragment(). In defragment routine, skb_orphan() is called and skb->ip_defrag_offset is set. but skb->sk and skb->ip_defrag_offset are same union member. so that frag->sk is not NULL. Hence crash occurrs in skb->sk check routine in ip_do_fragment() when defragmented packet is fragmented. test commands: %iptables -t nat -I POSTROUTING -j MASQUERADE %hping3 192.168.4.2 -s 1000 -p 2000 -d 60000 splat looks like: [ 261.069429] kernel BUG at net/ipv4/ip_output.c:636! [ 261.075753] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 261.083854] CPU: 1 PID: 1349 Comm: hping3 Not tainted 4.19.0-rc2+ #3 [ 261.100977] RIP: 0010:ip_do_fragment+0x1613/0x2600 [ 261.106945] Code: e8 e2 38 e3 fe 4c 8b 44 24 18 48 8b 74 24 08 e9 92 f6 ff ff 80 3c 02 00 0f 85 da 07 00 00 48 8b b5 d0 00 00 00 e9 25 f6 ff ff <0f> 0b 0f 0b 44 8b 54 24 58 4c 8b 4c 24 18 4c 8b 5c 24 60 4c 8b 6c [ 261.127015] RSP: 0018:ffff8801031cf2c0 EFLAGS: 00010202 [ 261.134156] RAX: 1ffff1002297537b RBX: ffffed0020639e6e RCX: 0000000000000004 [ 261.142156] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880114ba9bd8 [ 261.150157] RBP: ffff880114ba8a40 R08: ffffed0022975395 R09: ffffed0022975395 [ 261.158157] R10: 0000000000000001 R11: ffffed0022975394 R12: ffff880114ba9ca4 [ 261.166159] R13: 0000000000000010 R14: ffff880114ba9bc0 R15: dffffc0000000000 [ 261.174169] FS: 00007fbae2199700(0000) GS:ffff88011b400000(0000) knlGS:0000000000000000 [ 261.183012] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 261.189013] CR2: 00005579244fe000 CR3: 0000000119bf4000 CR4: 00000000001006e0 [ 261.198158] Call Trace: [ 261.199018] ? dst_output+0x180/0x180 [ 261.205011] ? save_trace+0x300/0x300 [ 261.209018] ? ip_copy_metadata+0xb00/0xb00 [ 261.213034] ? sched_clock_local+0xd4/0x140 [ 261.218158] ? kill_l4proto+0x120/0x120 [nf_conntrack] [ 261.223014] ? rt_cpu_seq_stop+0x10/0x10 [ 261.227014] ? find_held_lock+0x39/0x1c0 [ 261.233008] ip_finish_output+0x51d/0xb50 [ 261.237006] ? ip_fragment.constprop.56+0x220/0x220 [ 261.243011] ? nf_ct_l4proto_register_one+0x5b0/0x5b0 [nf_conntrack] [ 261.250152] ? rcu_is_watching+0x77/0x120 [ 261.255010] ? nf_nat_ipv4_out+0x1e/0x2b0 [nf_nat_ipv4] [ 261.261033] ? nf_hook_slow+0xb1/0x160 [ 261.265007] ip_output+0x1c7/0x710 [ 261.269005] ? ip_mc_output+0x13f0/0x13f0 [ 261.273002] ? __local_bh_enable_ip+0xe9/0x1b0 [ 261.278152] ? ip_fragment.constprop.56+0x220/0x220 [ 261.282996] ? nf_hook_slow+0xb1/0x160 [ 261.287007] raw_sendmsg+0x21f9/0x4420 [ 261.291008] ? dst_output+0x180/0x180 [ 261.297003] ? sched_clock_cpu+0x126/0x170 [ 261.301003] ? find_held_lock+0x39/0x1c0 [ 261.306155] ? stop_critical_timings+0x420/0x420 [ 261.311004] ? check_flags.part.36+0x450/0x450 [ 261.315005] ? _raw_spin_unlock_irq+0x29/0x40 [ 261.320995] ? _raw_spin_unlock_irq+0x29/0x40 [ 261.326142] ? cyc2ns_read_end+0x10/0x10 [ 261.330139] ? raw_bind+0x280/0x280 [ 261.334138] ? sched_clock_cpu+0x126/0x170 [ 261.338995] ? check_flags.part.36+0x450/0x450 [ 261.342991] ? __lock_acquire+0x4500/0x4500 [ 261.348994] ? inet_sendmsg+0x11c/0x500 [ 261.352989] ? dst_output+0x180/0x180 [ 261.357012] inet_sendmsg+0x11c/0x500 [ ... ] v2: - clear skb->sk at reassembly routine.(Eric Dumarzet) Fixes: fa0f527358bd ("ip: use rb trees for IP frag queue.") Suggested-by: Eric Dumazet Signed-off-by: Taehee Yoo Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv6/netfilter/nf_conntrack_reasm.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/ipv6') diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index 2a14d8b65924..8f68a518d9db 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -445,6 +445,7 @@ nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *prev, struct net_devic else if (head->ip_summed == CHECKSUM_COMPLETE) head->csum = csum_add(head->csum, fp->csum); head->truesize += fp->truesize; + fp->sk = NULL; } sub_frag_mem_limit(fq->q.net, head->truesize); -- cgit v1.2.3 From 22d0bd82cc7cec7d9ed4bd5913f3ab65643364be Mon Sep 17 00:00:00 2001 From: Xin Long Date: Tue, 11 Sep 2018 14:33:58 +0800 Subject: ipv6: use rt6_info members when dst is set in rt6_fill_node In inet6_rtm_getroute, since Commit 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes"), it has used rt->from to dump route info instead of rt. However for some route like cache, some of its information like flags or gateway is not the same as that of the 'from' one. It caused 'ip route get' to dump the wrong route information. In Jianlin's testing, the output information even lost the expiration time for a pmtu route cache due to the wrong fib6_flags. So change to use rt6_info members for dst addr, src addr, flags and gateway when it tries to dump a route entry without fibmatch set. v1->v2: - not use rt6i_prefsrc. - also fix the gw dump issue. Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes") Reported-by: Jianlin Shi Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/ipv6/route.c | 42 ++++++++++++++++++++++++++++++------------ 1 file changed, 30 insertions(+), 12 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 18e00ce1719a..3eed045c65a5 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -4670,20 +4670,31 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb, int iif, int type, u32 portid, u32 seq, unsigned int flags) { - struct rtmsg *rtm; + struct rt6_info *rt6 = (struct rt6_info *)dst; + struct rt6key *rt6_dst, *rt6_src; + u32 *pmetrics, table, rt6_flags; struct nlmsghdr *nlh; + struct rtmsg *rtm; long expires = 0; - u32 *pmetrics; - u32 table; nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags); if (!nlh) return -EMSGSIZE; + if (rt6) { + rt6_dst = &rt6->rt6i_dst; + rt6_src = &rt6->rt6i_src; + rt6_flags = rt6->rt6i_flags; + } else { + rt6_dst = &rt->fib6_dst; + rt6_src = &rt->fib6_src; + rt6_flags = rt->fib6_flags; + } + rtm = nlmsg_data(nlh); rtm->rtm_family = AF_INET6; - rtm->rtm_dst_len = rt->fib6_dst.plen; - rtm->rtm_src_len = rt->fib6_src.plen; + rtm->rtm_dst_len = rt6_dst->plen; + rtm->rtm_src_len = rt6_src->plen; rtm->rtm_tos = 0; if (rt->fib6_table) table = rt->fib6_table->tb6_id; @@ -4698,7 +4709,7 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb, rtm->rtm_scope = RT_SCOPE_UNIVERSE; rtm->rtm_protocol = rt->fib6_protocol; - if (rt->fib6_flags & RTF_CACHE) + if (rt6_flags & RTF_CACHE) rtm->rtm_flags |= RTM_F_CLONED; if (dest) { @@ -4706,7 +4717,7 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb, goto nla_put_failure; rtm->rtm_dst_len = 128; } else if (rtm->rtm_dst_len) - if (nla_put_in6_addr(skb, RTA_DST, &rt->fib6_dst.addr)) + if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr)) goto nla_put_failure; #ifdef CONFIG_IPV6_SUBTREES if (src) { @@ -4714,12 +4725,12 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb, goto nla_put_failure; rtm->rtm_src_len = 128; } else if (rtm->rtm_src_len && - nla_put_in6_addr(skb, RTA_SRC, &rt->fib6_src.addr)) + nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr)) goto nla_put_failure; #endif if (iif) { #ifdef CONFIG_IPV6_MROUTE - if (ipv6_addr_is_multicast(&rt->fib6_dst.addr)) { + if (ipv6_addr_is_multicast(&rt6_dst->addr)) { int err = ip6mr_get_route(net, skb, rtm, portid); if (err == 0) @@ -4754,7 +4765,14 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb, /* For multipath routes, walk the siblings list and add * each as a nexthop within RTA_MULTIPATH. */ - if (rt->fib6_nsiblings) { + if (rt6) { + if (rt6_flags & RTF_GATEWAY && + nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway)) + goto nla_put_failure; + + if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex)) + goto nla_put_failure; + } else if (rt->fib6_nsiblings) { struct fib6_info *sibling, *next_sibling; struct nlattr *mp; @@ -4777,7 +4795,7 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb, goto nla_put_failure; } - if (rt->fib6_flags & RTF_EXPIRES) { + if (rt6_flags & RTF_EXPIRES) { expires = dst ? dst->expires : rt->expires; expires -= jiffies; } @@ -4785,7 +4803,7 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb, if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0) goto nla_put_failure; - if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt->fib6_flags))) + if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags))) goto nla_put_failure; -- cgit v1.2.3 From c56cae23c6b167acc68043c683c4573b80cbcc2c Mon Sep 17 00:00:00 2001 From: Toke Høiland-Jørgensen Date: Thu, 13 Sep 2018 16:43:07 +0200 Subject: gso_segment: Reset skb->mac_len after modifying network header MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When splitting a GSO segment that consists of encapsulated packets, the skb->mac_len of the segments can end up being set wrong, causing packet drops in particular when using act_mirred and ifb interfaces in combination with a qdisc that splits GSO packets. This happens because at the time skb_segment() is called, network_header will point to the inner header, throwing off the calculation in skb_reset_mac_len(). The network_header is subsequently adjust by the outer IP gso_segment handlers, but they don't set the mac_len. Fix this by adding skb_reset_mac_len() calls to both the IPv4 and IPv6 gso_segment handlers, after they modify the network_header. Many thanks to Eric Dumazet for his help in identifying the cause of the bug. Acked-by: Dave Taht Reviewed-by: Eric Dumazet Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: David S. Miller --- net/ipv4/af_inet.c | 1 + net/ipv6/ip6_offload.c | 1 + 2 files changed, 2 insertions(+) (limited to 'net/ipv6') diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 20fda8fb8ffd..1fbe2f815474 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1377,6 +1377,7 @@ struct sk_buff *inet_gso_segment(struct sk_buff *skb, if (encap) skb_reset_inner_headers(skb); skb->network_header = (u8 *)iph - skb->head; + skb_reset_mac_len(skb); } while ((skb = skb->next)); out: diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c index 37ff4805b20c..c7e495f12011 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -115,6 +115,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, payload_len = skb->len - nhoff - sizeof(*ipv6h); ipv6h->payload_len = htons(payload_len); skb->network_header = (u8 *)ipv6h - skb->head; + skb_reset_mac_len(skb); if (udpfrag) { int err = ip6_find_1stfragopt(skb, &prevhdr); -- cgit v1.2.3 From eb63f2964dbe36f26deac77d3016791675821ded Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Thu, 13 Sep 2018 16:27:21 +0200 Subject: udp6: add missing checks on edumux packet processing Currently the UDPv6 early demux rx code path lacks some mandatory checks, already implemented into the normal RX code path - namely the checksum conversion and no_check6_rx check. Similar to the previous commit, we move the common processing to an UDPv6 specific helper and call it from both edemux code path and normal code path. In respect to the UDPv4, we need to add an explicit check for non zero csum according to no_check6_rx value. Reported-by: Jianlin Shi Suggested-by: Xin Long Fixes: c9f2c1ae123a ("udp6: fix socket leak on early demux") Fixes: 2abb7cdc0dc8 ("udp: Add support for doing checksum unnecessary conversion") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller --- net/ipv6/udp.c | 65 +++++++++++++++++++++++++++++++++------------------------- 1 file changed, 37 insertions(+), 28 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 83f4c77c79d8..28c4aa5078fc 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -752,6 +752,28 @@ static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) } } +/* wrapper for udp_queue_rcv_skb tacking care of csum conversion and + * return code conversion for ip layer consumption + */ +static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb, + struct udphdr *uh) +{ + int ret; + + if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) + skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check, + ip6_compute_pseudo); + + ret = udpv6_queue_rcv_skb(sk, skb); + + /* a return value > 0 means to resubmit the input, but + * it wants the return to be -protocol, or 0 + */ + if (ret > 0) + return -ret; + return 0; +} + int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, int proto) { @@ -803,13 +825,14 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, if (unlikely(sk->sk_rx_dst != dst)) udp6_sk_rx_dst_set(sk, dst); - ret = udpv6_queue_rcv_skb(sk, skb); - sock_put(sk); + if (!uh->check && !udp_sk(sk)->no_check6_rx) { + sock_put(sk); + goto report_csum_error; + } - /* a return value > 0 means to resubmit the input */ - if (ret > 0) - return ret; - return 0; + ret = udp6_unicast_rcv_skb(sk, skb, uh); + sock_put(sk); + return ret; } /* @@ -822,30 +845,13 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, /* Unicast */ sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable); if (sk) { - int ret; - - if (!uh->check && !udp_sk(sk)->no_check6_rx) { - udp6_csum_zero_error(skb); - goto csum_error; - } - - if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) - skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check, - ip6_compute_pseudo); - - ret = udpv6_queue_rcv_skb(sk, skb); - - /* a return value > 0 means to resubmit the input */ - if (ret > 0) - return ret; - - return 0; + if (!uh->check && !udp_sk(sk)->no_check6_rx) + goto report_csum_error; + return udp6_unicast_rcv_skb(sk, skb, uh); } - if (!uh->check) { - udp6_csum_zero_error(skb); - goto csum_error; - } + if (!uh->check) + goto report_csum_error; if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) goto discard; @@ -866,6 +872,9 @@ short_packet: ulen, skb->len, daddr, ntohs(uh->dest)); goto discard; + +report_csum_error: + udp6_csum_zero_error(skb); csum_error: __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); discard: -- cgit v1.2.3 From bbd6528d28c1b8e80832b3b018ec402b6f5c3215 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 14 Sep 2018 12:02:31 -0700 Subject: ipv6: fix possible use-after-free in ip6_xmit() In the unlikely case ip6_xmit() has to call skb_realloc_headroom(), we need to call skb_set_owner_w() before consuming original skb, otherwise we risk a use-after-free. Bring IPv6 in line with what we do in IPv4 to fix this. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller --- net/ipv6/ip6_output.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 16f200f06500..f9f8f554d141 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -219,12 +219,10 @@ int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, kfree_skb(skb); return -ENOBUFS; } + if (skb->sk) + skb_set_owner_w(skb2, skb->sk); consume_skb(skb); skb = skb2; - /* skb_set_owner_w() changes sk->sk_wmem_alloc atomically, - * it is safe to call in our context (socket lock not held) - */ - skb_set_owner_w(skb, (struct sock *)sk); } if (opt->opt_flen) ipv6_push_frag_opts(skb, opt, &proto); -- cgit v1.2.3 From 30bfd93062814d6767e452a8f5ddcd97f7e38c7e Mon Sep 17 00:00:00 2001 From: Peter Oskolkov Date: Mon, 17 Sep 2018 10:20:53 -0700 Subject: net/ipv6: do not copy dst flags on rt init DST_NOCOUNT in dst_entry::flags tracks whether the entry counts toward route cache size (net->ipv6.sysctl.ip6_rt_max_size). If the flag is NOT set, dst_ops::pcpuc_entries counter is incremented in dist_init() and decremented in dst_destroy(). This flag is tied to allocation/deallocation of dst_entry and should not be copied from another dst/route. Otherwise it can happen that dst_ops::pcpuc_entries counter grows until no new routes can be allocated because the counter reached ip6_rt_max_size due to DST_NOCOUNT not set and thus no counter decrements on gc-ed routes. Fixes: 3b6761d18bc1 ("net/ipv6: Move dst flags to booleans in fib entries") Cc: David Ahern Acked-by: Wei Wang Signed-off-by: Peter Oskolkov Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/route.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 3eed045c65a5..480a79f47c52 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -946,8 +946,6 @@ static void ip6_rt_init_dst_reject(struct rt6_info *rt, struct fib6_info *ort) static void ip6_rt_init_dst(struct rt6_info *rt, struct fib6_info *ort) { - rt->dst.flags |= fib6_info_dst_flags(ort); - if (ort->fib6_flags & RTF_REJECT) { ip6_rt_init_dst_reject(rt, ort); return; -- cgit v1.2.3 From 8675860592321a43bbb0b5aedc244a9b2321edc3 Mon Sep 17 00:00:00 2001 From: Wei Wang Date: Tue, 18 Sep 2018 13:44:59 -0700 Subject: Revert "ipv6: fix double refcount of fib6_metrics" This reverts commit e70a3aad44cc8b24986687ffc98c4a4f6ecf25ea. This change causes use-after-free on dst->_metrics. The crash trace looks like this: [ 97.763269] BUG: KASAN: use-after-free in ip6_mtu+0x116/0x140 [ 97.769038] Read of size 4 at addr ffff881781d2cf84 by task svw_NetThreadEv/8801 [ 97.777954] CPU: 76 PID: 8801 Comm: svw_NetThreadEv Not tainted 4.15.0-smp-DEV #11 [ 97.777956] Hardware name: Default string Default string/Indus_QC_02, BIOS 5.46.4 03/29/2018 [ 97.777957] Call Trace: [ 97.777971] [] dump_stack+0x4d/0x72 [ 97.777985] [] print_address_description+0x6f/0x260 [ 97.777997] [] kasan_report+0x257/0x370 [ 97.778001] [] ? ip6_mtu+0x116/0x140 [ 97.778004] [] __asan_report_load4_noabort+0x19/0x20 [ 97.778008] [] ip6_mtu+0x116/0x140 [ 97.778013] [] tcp_current_mss+0x12e/0x280 [ 97.778016] [] ? tcp_mtu_to_mss+0x2d0/0x2d0 [ 97.778022] [] ? depot_save_stack+0x138/0x4a0 [ 97.778037] [] ? __mmdrop+0x145/0x1f0 [ 97.778040] [] ? save_stack+0xb1/0xd0 [ 97.778046] [] tcp_send_mss+0x22/0x220 [ 97.778059] [] tcp_sendmsg_locked+0x4f9/0x39f0 [ 97.778062] [] ? kasan_check_write+0x14/0x20 [ 97.778066] [] ? tcp_sendpage+0x60/0x60 [ 97.778070] [] ? rw_copy_check_uvector+0x69/0x280 [ 97.778075] [] ? import_iovec+0x9f/0x430 [ 97.778078] [] ? kasan_slab_free+0x87/0xc0 [ 97.778082] [] ? memzero_page+0x140/0x140 [ 97.778085] [] ? kasan_check_write+0x14/0x20 [ 97.778088] [] tcp_sendmsg+0x2c/0x50 [ 97.778092] [] ? tcp_sendmsg+0x2c/0x50 [ 97.778098] [] inet_sendmsg+0x103/0x480 [ 97.778102] [] ? inet_gso_segment+0x15b0/0x15b0 [ 97.778105] [] sock_sendmsg+0xba/0xf0 [ 97.778108] [] ___sys_sendmsg+0x6ca/0x8e0 [ 97.778113] [] ? hrtimer_try_to_cancel+0x71/0x3b0 [ 97.778116] [] ? copy_msghdr_from_user+0x3d0/0x3d0 [ 97.778119] [] ? memset+0x31/0x40 [ 97.778123] [] ? schedule_hrtimeout_range_clock+0x165/0x380 [ 97.778127] [] ? hrtimer_nanosleep_restart+0x250/0x250 [ 97.778130] [] ? __hrtimer_init+0x180/0x180 [ 97.778133] [] ? ktime_get_ts64+0x172/0x200 [ 97.778137] [] ? __fget_light+0x8c/0x2f0 [ 97.778141] [] __sys_sendmsg+0xe6/0x190 [ 97.778144] [] ? __sys_sendmsg+0xe6/0x190 [ 97.778147] [] ? SyS_shutdown+0x20/0x20 [ 97.778152] [] ? wake_up_q+0xe0/0xe0 [ 97.778155] [] ? __sys_sendmsg+0x190/0x190 [ 97.778158] [] SyS_sendmsg+0x13/0x20 [ 97.778162] [] do_syscall_64+0x2ac/0x430 [ 97.778166] [] ? do_page_fault+0x35/0x3d0 [ 97.778171] [] ? page_fault+0x2f/0x50 [ 97.778174] [] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [ 97.778177] RIP: 0033:0x7f83fa36000d [ 97.778178] RSP: 002b:00007f83ef9229e0 EFLAGS: 00000293 ORIG_RAX: 000000000000002e [ 97.778180] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f83fa36000d [ 97.778182] RDX: 0000000000004000 RSI: 00007f83ef922f00 RDI: 0000000000000036 [ 97.778183] RBP: 00007f83ef923040 R08: 00007f83ef9231f8 R09: 00007f83ef923168 [ 97.778184] R10: 0000000000000000 R11: 0000000000000293 R12: 00007f83f69c5b40 [ 97.778185] R13: 000000000000001c R14: 0000000000000001 R15: 0000000000004000 [ 97.779684] Allocated by task 5919: [ 97.783185] save_stack+0x46/0xd0 [ 97.783187] kasan_kmalloc+0xad/0xe0 [ 97.783189] kmem_cache_alloc_trace+0xdf/0x580 [ 97.783190] ip6_convert_metrics.isra.79+0x7e/0x190 [ 97.783192] ip6_route_info_create+0x60a/0x2480 [ 97.783193] ip6_route_add+0x1d/0x80 [ 97.783195] inet6_rtm_newroute+0xdd/0xf0 [ 97.783198] rtnetlink_rcv_msg+0x641/0xb10 [ 97.783200] netlink_rcv_skb+0x27b/0x3e0 [ 97.783202] rtnetlink_rcv+0x15/0x20 [ 97.783203] netlink_unicast+0x4be/0x720 [ 97.783204] netlink_sendmsg+0x7bc/0xbf0 [ 97.783205] sock_sendmsg+0xba/0xf0 [ 97.783207] ___sys_sendmsg+0x6ca/0x8e0 [ 97.783208] __sys_sendmsg+0xe6/0x190 [ 97.783209] SyS_sendmsg+0x13/0x20 [ 97.783211] do_syscall_64+0x2ac/0x430 [ 97.783213] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [ 97.784709] Freed by task 0: [ 97.785056] knetbase: Error: /proc/sys/net/core/txcs_enable does not exist [ 97.794497] save_stack+0x46/0xd0 [ 97.794499] kasan_slab_free+0x71/0xc0 [ 97.794500] kfree+0x7c/0xf0 [ 97.794501] fib6_info_destroy_rcu+0x24f/0x310 [ 97.794504] rcu_process_callbacks+0x38b/0x1730 [ 97.794506] __do_softirq+0x1c8/0x5d0 Reported-by: John Sperbeck Signed-off-by: Wei Wang Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/route.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'net/ipv6') diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 480a79f47c52..b5d3e6b294ab 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -976,6 +976,10 @@ static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from) rt->rt6i_flags &= ~RTF_EXPIRES; rcu_assign_pointer(rt->from, from); dst_init_metrics(&rt->dst, from->fib6_metrics->metrics, true); + if (from->fib6_metrics != &dst_default_metrics) { + rt->dst._metrics |= DST_METRICS_REFCOUNTED; + refcount_inc(&from->fib6_metrics->refcnt); + } } /* Caller must already hold reference to @ort */ -- cgit v1.2.3 From ce7ea4af0838ffd4667ecad4eb5eec7a25342f1e Mon Sep 17 00:00:00 2001 From: Wei Wang Date: Tue, 18 Sep 2018 13:45:00 -0700 Subject: ipv6: fix memory leak on dst->_metrics When dst->_metrics and f6i->fib6_metrics share the same memory, both take reference count on the dst_metrics structure. However, when dst is destroyed, ip6_dst_destroy() only invokes dst_destroy_metrics_generic() which does not take care of READONLY metrics and does not release refcnt. This causes memory leak. Similar to ipv4 logic, the fix is to properly release refcnt and free the memory space pointed by dst->_metrics if refcnt becomes 0. Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes") Reported-by: Sabrina Dubroca Signed-off-by: Wei Wang Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/route.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'net/ipv6') diff --git a/net/ipv6/route.c b/net/ipv6/route.c index b5d3e6b294ab..826b14de7dbb 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -364,11 +364,14 @@ EXPORT_SYMBOL(ip6_dst_alloc); static void ip6_dst_destroy(struct dst_entry *dst) { + struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst); struct rt6_info *rt = (struct rt6_info *)dst; struct fib6_info *from; struct inet6_dev *idev; - dst_destroy_metrics_generic(dst); + if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt)) + kfree(p); + rt6_uncached_list_del(rt); idev = rt->rt6i_idev; -- cgit v1.2.3 From 76c0ddd8c3a683f6e2c6e60e11dc1a1558caf4bc Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Wed, 19 Sep 2018 15:02:07 +0200 Subject: ip6_tunnel: be careful when accessing the inner header the ip6 tunnel xmit ndo assumes that the processed skb always contains an ip[v6] header, but syzbot has found a way to send frames that fall short of this assumption, leading to the following splat: BUG: KMSAN: uninit-value in ip6ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1307 [inline] BUG: KMSAN: uninit-value in ip6_tnl_start_xmit+0x7d2/0x1ef0 net/ipv6/ip6_tunnel.c:1390 CPU: 0 PID: 4504 Comm: syz-executor558 Not tainted 4.16.0+ #87 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683 ip6ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1307 [inline] ip6_tnl_start_xmit+0x7d2/0x1ef0 net/ipv6/ip6_tunnel.c:1390 __netdev_start_xmit include/linux/netdevice.h:4066 [inline] netdev_start_xmit include/linux/netdevice.h:4075 [inline] xmit_one net/core/dev.c:3026 [inline] dev_hard_start_xmit+0x5f1/0xc70 net/core/dev.c:3042 __dev_queue_xmit+0x27ee/0x3520 net/core/dev.c:3557 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3590 packet_snd net/packet/af_packet.c:2944 [inline] packet_sendmsg+0x7c70/0x8a30 net/packet/af_packet.c:2969 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046 __sys_sendmmsg+0x42d/0x800 net/socket.c:2136 SYSC_sendmmsg+0xc4/0x110 net/socket.c:2167 SyS_sendmmsg+0x63/0x90 net/socket.c:2162 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x441819 RSP: 002b:00007ffe58ee8268 EFLAGS: 00000213 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441819 RDX: 0000000000000002 RSI: 0000000020000100 RDI: 0000000000000003 RBP: 00000000006cd018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000402510 R13: 00000000004025a0 R14: 0000000000000000 R15: 0000000000000000 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314 kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321 slab_post_alloc_hook mm/slab.h:445 [inline] slab_alloc_node mm/slub.c:2737 [inline] __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:984 [inline] alloc_skb_with_frags+0x1d4/0xb20 net/core/skbuff.c:5234 sock_alloc_send_pskb+0xb56/0x1190 net/core/sock.c:2085 packet_alloc_skb net/packet/af_packet.c:2803 [inline] packet_snd net/packet/af_packet.c:2894 [inline] packet_sendmsg+0x6454/0x8a30 net/packet/af_packet.c:2969 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046 __sys_sendmmsg+0x42d/0x800 net/socket.c:2136 SYSC_sendmmsg+0xc4/0x110 net/socket.c:2167 SyS_sendmmsg+0x63/0x90 net/socket.c:2162 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 This change addresses the issue adding the needed check before accessing the inner header. The ipv4 side of the issue is apparently there since the ipv4 over ipv6 initial support, and the ipv6 side predates git history. Fixes: c4d3efafcc93 ("[IPV6] IP6TUNNEL: Add support to IPv4 over IPv6 tunnel.") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+3fde91d4d394747d6db4@syzkaller.appspotmail.com Tested-by: Alexander Potapenko Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller --- net/ipv6/ip6_tunnel.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 419960b0ba16..a0b6932c3afd 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1234,7 +1234,7 @@ static inline int ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); - const struct iphdr *iph = ip_hdr(skb); + const struct iphdr *iph; int encap_limit = -1; struct flowi6 fl6; __u8 dsfield; @@ -1242,6 +1242,11 @@ ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) u8 tproto; int err; + /* ensure we can access the full inner ip header */ + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + return -1; + + iph = ip_hdr(skb); memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); tproto = READ_ONCE(t->parms.proto); @@ -1306,7 +1311,7 @@ static inline int ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); - struct ipv6hdr *ipv6h = ipv6_hdr(skb); + struct ipv6hdr *ipv6h; int encap_limit = -1; __u16 offset; struct flowi6 fl6; @@ -1315,6 +1320,10 @@ ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) u8 tproto; int err; + if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h)))) + return -1; + + ipv6h = ipv6_hdr(skb); tproto = READ_ONCE(t->parms.proto); if ((tproto != IPPROTO_IPV6 && tproto != 0) || ip6_tnl_addr_conflict(t, ipv6h)) -- cgit v1.2.3 From 86f9bd1ff61c413a2a251fa736463295e4e24733 Mon Sep 17 00:00:00 2001 From: Jeff Barnhill <0xeffeff@gmail.com> Date: Fri, 21 Sep 2018 00:45:27 +0000 Subject: net/ipv6: Display all addresses in output of /proc/net/if_inet6 The backend handling for /proc/net/if_inet6 in addrconf.c doesn't properly handle starting/stopping the iteration. The problem is that at some point during the iteration, an overflow is detected and the process is subsequently stopped. The item being shown via seq_printf() when the overflow occurs is not actually shown, though. When start() is subsequently called to resume iterating, it returns the next item, and thus the item that was being processed when the overflow occurred never gets printed. Alter the meaning of the private data member "offset". Currently, when it is not 0 (which only happens at the very beginning), "offset" represents the next hlist item to be printed. After this change, "offset" always represents the current item. This is also consistent with the private data member "bucket", which represents the current bucket, and also the use of "pos" as defined in seq_file.txt: The pos passed to start() will always be either zero, or the most recent pos used in the previous session. Signed-off-by: Jeff Barnhill <0xeffeff@gmail.com> Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index d51a8c0b3372..c63ccce6425f 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -4201,7 +4201,6 @@ static struct inet6_ifaddr *if6_get_first(struct seq_file *seq, loff_t pos) p++; continue; } - state->offset++; return ifa; } @@ -4225,13 +4224,12 @@ static struct inet6_ifaddr *if6_get_next(struct seq_file *seq, return ifa; } + state->offset = 0; while (++state->bucket < IN6_ADDR_HSIZE) { - state->offset = 0; hlist_for_each_entry_rcu(ifa, &inet6_addr_lst[state->bucket], addr_lst) { if (!net_eq(dev_net(ifa->idev->dev), net)) continue; - state->offset++; return ifa; } } -- cgit v1.2.3