wireguard-linux/net, branch jd/shorter-socket-lock

drop_monitor: work around gcc-10 stringop-overflow warning

2020-05-01T22:45:16Z

The current gcc-10 snapshot produces a false-positive warning: net/core/drop_monitor.c: In function 'trace_drop_common.constprop': cc1: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=] In file included from net/core/drop_monitor.c:23: include/uapi/linux/net_dropmon.h:36:8: note: at offset 0 to object 'entries' with size 4 declared here 36 | __u32 entries; | ^~~~~~~ I reported this in the gcc bugzilla, but in case it does not get fixed in the release, work around it by using a temporary variable. Fixes: 9a8afc8d3962 ("Network Drop Monitor: Adding drop monitor implementation & Netlink protocol") Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94881 Signed-off-by: Arnd Bergmann Acked-by: Neil Horman Signed-off-by: David S. Miller

devlink: fix return value after hitting end in region read

2020-05-01T22:25:35Z

Commit d5b90e99e1d5 ("devlink: report 0 after hitting end in region read") fixed region dump, but region read still returns a spurious error: $ devlink region read netdevsim/netdevsim1/dummy snapshot 0 addr 0 len 128 0000000000000000 a6 f4 c4 1c 21 35 95 a6 9d 34 c3 5b 87 5b 35 79 0000000000000010 f3 a0 d7 ee 4f 2f 82 7f c6 dd c4 f6 a5 c3 1b ae 0000000000000020 a4 fd c8 62 07 59 48 03 70 3b c7 09 86 88 7f 68 0000000000000030 6f 45 5d 6d 7d 0e 16 38 a9 d0 7a 4b 1e 1e 2e a6 0000000000000040 e6 1d ae 06 d6 18 00 85 ca 62 e8 7e 11 7e f6 0f 0000000000000050 79 7e f7 0f f3 94 68 bd e6 40 22 85 b6 be 6f b1 0000000000000060 af db ef 5e 34 f0 98 4b 62 9a e3 1b 8b 93 fc 17 devlink answers: Invalid argument 0000000000000070 61 e8 11 11 66 10 a5 f7 b1 ea 8d 40 60 53 ed 12 This is a minimal fix, I'll follow up with a restructuring so we don't have two checks for the same condition. Fixes: fdd41ec21e15 ("devlink: Return right error code in case of errors for region read") Signed-off-by: Jakub Kicinski Reviewed-by: Jacob Keller Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

ipv6: Use global sernum for dst validation with nexthop objects

2020-05-01T19:46:30Z

Nik reported a bug with pcpu dst cache when nexthop objects are used illustrated by the following: $ ip netns add foo $ ip -netns foo li set lo up $ ip -netns foo addr add 2001:db8:11::1/128 dev lo $ ip netns exec foo sysctl net.ipv6.conf.all.forwarding=1 $ ip li add veth1 type veth peer name veth2 $ ip li set veth1 up $ ip addr add 2001:db8:10::1/64 dev veth1 $ ip li set dev veth2 netns foo $ ip -netns foo li set veth2 up $ ip -netns foo addr add 2001:db8:10::2/64 dev veth2 $ ip -6 nexthop add id 100 via 2001:db8:10::2 dev veth1 $ ip -6 route add 2001:db8:11::1/128 nhid 100 Create a pcpu entry on cpu 0: $ taskset -a -c 0 ip -6 route get 2001:db8:11::1 Re-add the route entry: $ ip -6 ro del 2001:db8:11::1 $ ip -6 route add 2001:db8:11::1/128 nhid 100 Route get on cpu 0 returns the stale pcpu: $ taskset -a -c 0 ip -6 route get 2001:db8:11::1 RTNETLINK answers: Network is unreachable While cpu 1 works: $ taskset -a -c 1 ip -6 route get 2001:db8:11::1 2001:db8:11::1 from :: via 2001:db8:10::2 dev veth1 src 2001:db8:10::1 metric 1024 pref medium Conversion of FIB entries to work with external nexthop objects missed an important difference between IPv4 and IPv6 - how dst entries are invalidated when the FIB changes. IPv4 has a per-network namespace generation id (rt_genid) that is bumped on changes to the FIB. Checking if a dst_entry is still valid means comparing rt_genid in the rtable to the current value of rt_genid for the namespace. IPv6 also has a per network namespace counter, fib6_sernum, but the count is saved per fib6_node. With the per-node counter only dst_entries based on fib entries under the node are invalidated when changes are made to the routes - limiting the scope of invalidations. IPv6 uses a reference in the rt6_info, 'from', to track the corresponding fib entry used to create the dst_entry. When validating a dst_entry, the 'from' is used to backtrack to the fib6_node and check the sernum of it to the cookie passed to the dst_check operation. With the inline format (nexthop definition inline with the fib6_info), dst_entries cached in the fib6_nh have a 1:1 correlation between fib entries, nexthop data and dst_entries. With external nexthops, IPv6 looks more like IPv4 which means multiple fib entries across disparate fib6_nodes can all reference the same fib6_nh. That means validation of dst_entries based on external nexthops needs to use the IPv4 format - the per-network namespace counter. Add sernum to rt6_info and set it when creating a pcpu dst entry. Update rt6_get_cookie to return sernum if it is set and update dst_check for IPv6 to look for sernum set and based the check on it if so. Finally, rt6_get_pcpu_route needs to validate the cached entry before returning a pcpu entry (similar to the rt_cache_valid calls in __mkroute_input and __mkroute_output for IPv4). This problem only affects routes using the new, external nexthops. Thanks to the kbuild test robot for catching the IS_ENABLED needed around rt_genid_ipv6 before I sent this out. Fixes: 5b98324ebe29 ("ipv6: Allow routes to use nexthop objects") Reported-by: Nikolay Aleksandrov Signed-off-by: David Ahern Reviewed-by: Nikolay Aleksandrov Tested-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

2020-05-01T01:07:16Z

Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for net: 1) Do not update the UDP checksum when it's zero, from Guillaume Nault. 2) Fix return of local variable in nf_osf, from Arnd Bergmann. ==================== Signed-off-by: David S. Miller

net: bridge: vlan: Add a schedule point during VLAN processing

2020-05-01T00:45:41Z

User space can request to delete a range of VLANs from a bridge slave in one netlink request. For each deleted VLAN the FDB needs to be traversed in order to flush all the affected entries. If a large range of VLANs is deleted and the number of FDB entries is large or the FDB lock is contented, it is possible for the kernel to loop through the deleted VLANs for a long time. In case preemption is disabled, this can result in a soft lockup. Fix this by adding a schedule point after each VLAN is deleted to yield the CPU, if needed. This is safe because the VLANs are traversed in process context. Fixes: bdced7ef7838 ("bridge: support for multiple vlans and vlan ranges in setlink and dellink requests") Signed-off-by: Ido Schimmel Reported-by: Stefan Priebe - Profihost AG Tested-by: Stefan Priebe - Profihost AG Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

mptcp: fix uninitialized value access

2020-04-30T19:34:07Z

tcp_v{4,6}_syn_recv_sock() set 'own_req' only when returning a not NULL 'child', let's check 'own_req' only if child is available to avoid an - unharmful - UBSAN splat. v1 -> v2: - reference the correct hash Fixes: 4c8941de781c ("mptcp: avoid flipping mp_capable field in syn_recv_sock()") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

mptcp: initialize the data_fin field for mpc packets

2020-04-30T19:23:23Z

When parsing MPC+data packets we set the dss field, so we must also initialize the data_fin, or we can find stray value there. Fixes: 9a19371bf029 ("mptcp: fix data_fin handing in RX path") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

mptcp: fix 'use_ack' option access.

2020-04-30T19:23:22Z

The mentioned RX option field is initialized only for DSS packet, we must access it only if 'dss' is set too, or the subflow will end-up in a bad status, leading to RFC violations. Fixes: d22f4988ffec ("mptcp: process MP_CAPABLE data option") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

mptcp: avoid a WARN on bad input.

2020-04-30T19:23:22Z

Syzcaller has found a way to trigger the WARN_ON_ONCE condition in check_fully_established(). The root cause is a legit fallback to TCP scenario, so replace the WARN with a plain message on a more strict condition. Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

mptcp: move option parsing into mptcp_incoming_options()

2020-04-30T19:23:22Z

The mptcp_options_received structure carries several per packet flags (mp_capable, mp_join, etc.). Such fields must be cleared on each packet, even on dropped ones or packet not carrying any MPTCP options, but the current mptcp code clears them only on TCP option reset. On several races/corner cases we end-up with stray bits in incoming options, leading to WARN_ON splats. e.g.: [ 171.164906] Bad mapping: ssn=32714 map_seq=1 map_data_len=32713 [ 171.165006] WARNING: CPU: 1 PID: 5026 at net/mptcp/subflow.c:533 warn_bad_map (linux-mptcp/net/mptcp/subflow.c:533 linux-mptcp/net/mptcp/subflow.c:531) [ 171.167632] Modules linked in: ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel geneve ip6_udp_tunnel udp_tunnel macsec macvtap tap ipvlan macvlan 8021q garp mrp xfrm_interface veth netdevsim nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun binfmt_misc intel_rapl_msr intel_rapl_common rfkill kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel joydev virtio_balloon pcspkr i2c_piix4 sunrpc ip_tables xfs libcrc32c crc32c_intel serio_raw virtio_console ata_generic virtio_blk virtio_net net_failover failover ata_piix libata [ 171.199464] CPU: 1 PID: 5026 Comm: repro Not tainted 5.7.0-rc1.mptcp_f227fdf5d388+ #95 [ 171.200886] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014 [ 171.202546] RIP: 0010:warn_bad_map (linux-mptcp/net/mptcp/subflow.c:533 linux-mptcp/net/mptcp/subflow.c:531) [ 171.206537] Code: c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1d 8b 55 3c 44 89 e6 48 c7 c7 20 51 13 95 e8 37 8b 22 fe <0f> 0b 48 83 c4 08 5b 5d 41 5c c3 89 4c 24 04 e8 db d6 94 fe 8b 4c [ 171.220473] RSP: 0018:ffffc90000150560 EFLAGS: 00010282 [ 171.221639] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 171.223108] RDX: 0000000000000000 RSI: 0000000000000008 RDI: fffff5200002a09e [ 171.224388] RBP: ffff8880aa6e3c00 R08: 0000000000000001 R09: fffffbfff2ec9955 [ 171.225706] R10: ffffffff9764caa7 R11: fffffbfff2ec9954 R12: 0000000000007fca [ 171.227211] R13: ffff8881066f4a7f R14: ffff8880aa6e3c00 R15: 0000000000000020 [ 171.228460] FS: 00007f8623719740(0000) GS:ffff88810be00000(0000) knlGS:0000000000000000 [ 171.230065] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 171.231303] CR2: 00007ffdab190a50 CR3: 00000001038ea006 CR4: 0000000000160ee0 [ 171.232586] Call Trace: [ 171.233109] [ 171.233531] get_mapping_status (linux-mptcp/net/mptcp/subflow.c:691) [ 171.234371] mptcp_subflow_data_available (linux-mptcp/net/mptcp/subflow.c:736 linux-mptcp/net/mptcp/subflow.c:832) [ 171.238181] subflow_state_change (linux-mptcp/net/mptcp/subflow.c:1085 (discriminator 1)) [ 171.239066] tcp_fin (linux-mptcp/net/ipv4/tcp_input.c:4217) [ 171.240123] tcp_data_queue (linux-mptcp/./include/linux/compiler.h:199 linux-mptcp/net/ipv4/tcp_input.c:4822) [ 171.245083] tcp_rcv_established (linux-mptcp/./include/linux/skbuff.h:1785 linux-mptcp/./include/net/tcp.h:1774 linux-mptcp/./include/net/tcp.h:1847 linux-mptcp/net/ipv4/tcp_input.c:5238 linux-mptcp/net/ipv4/tcp_input.c:5730) [ 171.254089] tcp_v4_rcv (linux-mptcp/./include/linux/spinlock.h:393 linux-mptcp/net/ipv4/tcp_ipv4.c:2009) [ 171.258969] ip_protocol_deliver_rcu (linux-mptcp/net/ipv4/ip_input.c:204 (discriminator 1)) [ 171.260214] ip_local_deliver_finish (linux-mptcp/./include/linux/rcupdate.h:651 linux-mptcp/net/ipv4/ip_input.c:232) [ 171.261389] ip_local_deliver (linux-mptcp/./include/linux/netfilter.h:307 linux-mptcp/./include/linux/netfilter.h:301 linux-mptcp/net/ipv4/ip_input.c:252) [ 171.265884] ip_rcv (linux-mptcp/./include/linux/netfilter.h:307 linux-mptcp/./include/linux/netfilter.h:301 linux-mptcp/net/ipv4/ip_input.c:539) [ 171.273666] process_backlog (linux-mptcp/./include/linux/rcupdate.h:651 linux-mptcp/net/core/dev.c:6135) [ 171.275328] net_rx_action (linux-mptcp/net/core/dev.c:6572 linux-mptcp/net/core/dev.c:6640) [ 171.280472] __do_softirq (linux-mptcp/./arch/x86/include/asm/jump_label.h:25 linux-mptcp/./include/linux/jump_label.h:200 linux-mptcp/./include/trace/events/irq.h:142 linux-mptcp/kernel/softirq.c:293) [ 171.281379] do_softirq_own_stack (linux-mptcp/arch/x86/entry/entry_64.S:1083) [ 171.282358] We could address the issue clearing explicitly the relevant fields in several places - tcp_parse_option, tcp_fast_parse_options, possibly others. Instead we move the MPTCP option parsing into the already existing mptcp ingress hook, so that we need to clear the fields in a single place. This allows us dropping an MPTCP hook from the TCP code and removing the quite large mptcp_options_received from the tcp_sock struct. On the flip side, the MPTCP sockets will traverse the option space twice (in tcp_parse_option() and in mptcp_incoming_options(). That looks acceptable: we already do that for syn and 3rd ack packets, plain TCP socket will benefit from it, and even MPTCP sockets will experience better code locality, reducing the jumps between TCP and MPTCP code. v1 -> v2: - rebased on current '-net' tree Fixes: 648ef4b88673 ("mptcp: Implement MPTCP receive path") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller