kernel/linux.git/net, branch linux-5.9.y

net: tipc: prevent possible null deref of link

2020-12-21T12:28:18+00:00

[ Upstream commit 0398ba9e5a4b5675aa571e0445689d3c2e499c2d ] `tipc_node_apply_property` does a null check on a `tipc_link_entry` pointer but also accesses the same pointer out of the null check block. This triggers a warning on Coverity Static Analyzer because we're implying that `e->link` can BE null. Move "Update MTU for node link entry" line into if block to make sure that we're not in a state that `e->link` is null. Signed-off-by: Cengiz Can Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: sched: Fix dump of MPLS_OPT_LSE_LABEL attribute in cls_flower

2020-12-21T12:28:18+00:00

[ Upstream commit 7fdd375e383097a785bb65c66802e468f398bf82 ] TCA_FLOWER_KEY_MPLS_OPT_LSE_LABEL is a u32 attribute (MPLS label is 20 bits long). Fixes the following bug: $ tc filter add dev ethX ingress protocol mpls_uc \ flower mpls lse depth 2 label 256 \ action drop $ tc filter show dev ethX ingress filter protocol mpls_uc pref 49152 flower chain 0 filter protocol mpls_uc pref 49152 flower chain 0 handle 0x1 eth_type 8847 mpls lse depth 2 label 0 <-- invalid label 0, should be 256 ... Fixes: 61aec25a6db5 ("cls_flower: Support filtering on multiple MPLS Label Stack Entries") Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: flow_offload: Fix memory leak for indirect flow block

2020-12-21T12:28:17+00:00

[ Upstream commit 5137d303659d8c324e67814b1cc2e1bc0c0d9836 ] The offending commit introduces a cleanup callback that is invoked when the driver module is removed to clean up the tunnel device flow block. But it returns on the first iteration of the for loop. The remaining indirect flow blocks will never be freed. Fixes: 1fac52da5942 ("net: flow_offload: consolidate indirect flow_block infrastructure") CC: Pablo Neira Ayuso Signed-off-by: Chris Mi Reviewed-by: Roi Dayan Signed-off-by: Greg Kroah-Hartman

tcp: fix cwnd-limited bug for TSO deferral where we send nothing

2020-12-21T12:28:17+00:00

[ Upstream commit 299bcb55ecd1412f6df606e9dc0912d55610029e ] When cwnd is not a multiple of the TSO skb size of N*MSS, we can get into persistent scenarios where we have the following sequence: (1) ACK for full-sized skb of N*MSS arrives -> tcp_write_xmit() transmit full-sized skb with N*MSS -> move pacing release time forward -> exit tcp_write_xmit() because pacing time is in the future (2) TSQ callback or TCP internal pacing timer fires -> try to transmit next skb, but TSO deferral finds remainder of available cwnd is not big enough to trigger an immediate send now, so we defer sending until the next ACK. (3) repeat... So we can get into a case where we never mark ourselves as cwnd-limited for many seconds at a time, even with bulk/infinite-backlog senders, because: o In case (1) above, every time in tcp_write_xmit() we have enough cwnd to send a full-sized skb, we are not fully using the cwnd (because cwnd is not a multiple of the TSO skb size). So every time we send data, we are not cwnd limited, and so in the cwnd-limited tracking code in tcp_cwnd_validate() we mark ourselves as not cwnd-limited. o In case (2) above, every time in tcp_write_xmit() that we try to transmit the "remainder" of the cwnd but defer, we set the local variable is_cwnd_limited to true, but we do not send any packets, so sent_pkts is zero, so we don't call the cwnd-limited logic to update tp->is_cwnd_limited. Fixes: ca8a22634381 ("tcp: make cwnd-limited checks measurement-based, and gentler") Reported-by: Ingemar Johansson Signed-off-by: Neal Cardwell Signed-off-by: Yuchung Cheng Acked-by: Soheil Hassas Yeganeh Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20201209035759.1225145-1-ncardwell.kernel@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

ethtool: fix stack overflow in ethnl_parse_bitset()

2020-12-21T12:28:17+00:00

[ Upstream commit a770bf515613c6e12ae904c3593e26016de99448 ] Syzbot reported a stack overflow in bitmap_from_arr32() called from ethnl_parse_bitset() when bitset from netlink message is longer than target bitmap length. While ethnl_compact_sanity_checks() makes sure that trailing part is all zeros (i.e. the request does not try to touch bits kernel does not recognize), we also need to cap change_bits to nbits so that we don't try to write past the prepared bitmaps. Fixes: 88db6d1e4f62 ("ethtool: add ethnl_parse_bitset() helper") Reported-by: syzbot+9d39fa49d4df294aab93@syzkaller.appspotmail.com Signed-off-by: Michal Kubecek Link: https://lore.kernel.org/r/3487ee3a98e14cd526f55b6caaa959d2dcbcad9f.1607465316.git.mkubecek@suse.cz Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

tcp: select sane initial rcvq_space.space for big MSS

2020-12-21T12:28:17+00:00

[ Upstream commit 72d05c00d7ecda85df29abd046da7e41cc071c17 ] Before commit a337531b942b ("tcp: up initial rmem to 128KB and SYN rwin to around 64KB") small tcp_rmem[1] values were overridden by tcp_fixup_rcvbuf() to accommodate various MSS. This is no longer the case, and Hazem Mohamed Abuelfotoh reported that DRS would not work for MTU 9000 endpoints receiving regular (1500 bytes) frames. Root cause is that tcp_init_buffer_space() uses tp->rcv_wnd for upper limit of rcvq_space.space computation, while it can select later a smaller value for tp->rcv_ssthresh and tp->window_clamp. ss -temoi on receiver would show : skmem:(r0,rb131072,t0,tb46080,f0,w0,o0,bl0,d0) rcv_space:62496 rcv_ssthresh:56596 This means that TCP can not increase its window in tcp_grow_window(), and that DRS can never kick. Fix this by making sure that rcvq_space.space is not bigger than number of bytes that can be held in TCP receive queue. People unable/unwilling to change their kernel can work around this issue by selecting a bigger tcp_rmem[1] value as in : echo "4096 196608 6291456" >/proc/sys/net/ipv4/tcp_rmem Based on an initial report and patch from Hazem Mohamed Abuelfotoh https://lore.kernel.org/netdev/20201204180622.14285-1-abuehaze@amazon.com/ Fixes: a337531b942b ("tcp: up initial rmem to 128KB and SYN rwin to around 64KB") Fixes: 041a14d26715 ("tcp: start receiver buffer autotuning sooner") Reported-by: Hazem Mohamed Abuelfotoh Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

mptcp: print new line in mptcp_seq_show() if mptcp isn't in use

2020-12-21T12:28:16+00:00

[ Upstream commit f55628b3e7648198e9c072b52080c5dea8678adf ] When do cat /proc/net/netstat, the output isn't append with a new line, it looks like this: [root@localhost ~]# cat /proc/net/netstat ... MPTcpExt: 0 0 0 0 0 0 0 0 0 0 0 0 0[root@localhost ~]# This is because in mptcp_seq_show(), if mptcp isn't in use, net->mib.mptcp_statistics is NULL, so it just puts all 0 after "MPTcpExt:", and return, forgot the '\n'. After this patch: [root@localhost ~]# cat /proc/net/netstat ... MPTcpExt: 0 0 0 0 0 0 0 0 0 0 0 0 0 [root@localhost ~]# Fixes: fc518953bc9c8d7d ("mptcp: add and use MIB counter infrastructure") Signed-off-by: Jianguo Wu Acked-by: Florian Westphal Link: https://lore.kernel.org/r/142e2fd9-58d9-bb13-fb75-951cccc2331e@163.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

bridge: Fix a deadlock when enabling multicast snooping

2020-12-21T12:28:16+00:00

[ Upstream commit 851d0a73c90e6c8c63fef106c6c1e73df7e05d9d ] When enabling multicast snooping, bridge module deadlocks on multicast_lock if 1) IPv6 is enabled, and 2) there is an existing querier on the same L2 network. The deadlock was caused by the following sequence: While holding the lock, br_multicast_open calls br_multicast_join_snoopers, which eventually causes IP stack to (attempt to) send out a Listener Report (in igmp6_join_group). Since the destination Ethernet address is a multicast address, br_dev_xmit feeds the packet back to the bridge via br_multicast_rcv, which in turn calls br_multicast_add_group, which then deadlocks on multicast_lock. The fix is to move the call br_multicast_join_snoopers outside of the critical section. This works since br_multicast_join_snoopers only deals with IP and does not modify any multicast data structures of the bridge, so there's no need to hold the lock. Steps to reproduce: 1. sysctl net.ipv6.conf.all.force_mld_version=1 2. have another querier 3. ip link set dev bridge type bridge mcast_snooping 0 && \ ip link set dev bridge type bridge mcast_snooping 1 < deadlock > A typical call trace looks like the following: [ 936.251495] _raw_spin_lock+0x5c/0x68 [ 936.255221] br_multicast_add_group+0x40/0x170 [bridge] [ 936.260491] br_multicast_rcv+0x7ac/0xe30 [bridge] [ 936.265322] br_dev_xmit+0x140/0x368 [bridge] [ 936.269689] dev_hard_start_xmit+0x94/0x158 [ 936.273876] __dev_queue_xmit+0x5ac/0x7f8 [ 936.277890] dev_queue_xmit+0x10/0x18 [ 936.281563] neigh_resolve_output+0xec/0x198 [ 936.285845] ip6_finish_output2+0x240/0x710 [ 936.290039] __ip6_finish_output+0x130/0x170 [ 936.294318] ip6_output+0x6c/0x1c8 [ 936.297731] NF_HOOK.constprop.0+0xd8/0xe8 [ 936.301834] igmp6_send+0x358/0x558 [ 936.305326] igmp6_join_group.part.0+0x30/0xf0 [ 936.309774] igmp6_group_added+0xfc/0x110 [ 936.313787] __ipv6_dev_mc_inc+0x1a4/0x290 [ 936.317885] ipv6_dev_mc_inc+0x10/0x18 [ 936.321677] br_multicast_open+0xbc/0x110 [bridge] [ 936.326506] br_multicast_toggle+0xec/0x140 [bridge] Fixes: 4effd28c1245 ("bridge: join all-snoopers multicast address") Signed-off-by: Joseph Huang Acked-by: Nikolay Aleksandrov Link: https://lore.kernel.org/r/20201204235628.50653-1-Joseph.Huang@garmin.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

udp: fix the proto value passed to ip_protocol_deliver_rcu for the segments

2020-12-21T12:28:15+00:00

[ Upstream commit 10c678bd0a035ac2c64a9b26b222f20556227a53 ] Guillaume noticed that: for segments udp_queue_rcv_one_skb() returns the proto, and it should pass "ret" unmodified to ip_protocol_deliver_rcu(). Otherwize, with a negtive value passed, it will underflow inet_protos. This can be reproduced with IPIP FOU: # ip fou add port 5555 ipproto 4 # ethtool -K eth1 rx-gro-list on Fixes: cf329aa42b66 ("udp: cope with UDP GRO packet misdirection") Reported-by: Guillaume Nault Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: bridge: vlan: fix error return code in __vlan_add()

2020-12-21T12:28:15+00:00

[ Upstream commit ee4f52a8de2c6f78b01f10b4c330867d88c1653a ] Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Fixes: f8ed289fab84 ("bridge: vlan: use br_vlan_(get|put)_master to deal with refcounts") Reported-by: Hulk Robot Signed-off-by: Zhang Changzhong Acked-by: Nikolay Aleksandrov Link: https://lore.kernel.org/r/1607071737-33875-1-git-send-email-zhangchangzhong@huawei.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman