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2021-12-14udp: using datalen to cap max gso segmentsJianguo Wu1-1/+1
commit 158390e45612ef0fde160af0826f1740c36daf21 upstream. The max number of UDP gso segments is intended to cap to UDP_MAX_SEGMENTS, this is checked in udp_send_skb(): if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) { kfree_skb(skb); return -EINVAL; } skb->len contains network and transport header len here, we should use only data len instead. Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT") Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/900742e5-81fb-30dc-6e0b-375c6cdd7982@163.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08ipv4: convert fib_num_tclassid_users to atomic_tEric Dumazet3-5/+5
commit 213f5f8f31f10aa1e83187ae20fb7fa4e626b724 upstream. Before commit faa041a40b9f ("ipv4: Create cleanup helper for fib_nh") changes to net->ipv4.fib_num_tclassid_users were protected by RTNL. After the change, this is no longer the case, as free_fib_info_rcu() runs after rcu grace period, without rtnl being held. Fixes: faa041a40b9f ("ipv4: Create cleanup helper for fib_nh") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: David Ahern <dsahern@kernel.org> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08ipv6: fix memory leak in fib6_rule_suppressmsizanoen11-0/+1
commit cdef485217d30382f3bf6448c54b4401648fe3f1 upstream. The kernel leaks memory when a `fib` rule is present in IPv6 nftables firewall rules and a suppress_prefix rule is present in the IPv6 routing rules (used by certain tools such as wg-quick). In such scenarios, every incoming packet will leak an allocation in `ip6_dst_cache` slab cache. After some hours of `bpftrace`-ing and source code reading, I tracked down the issue to ca7a03c41753 ("ipv6: do not free rt if FIB_LOOKUP_NOREF is set on suppress rule"). The problem with that change is that the generic `args->flags` always have `FIB_LOOKUP_NOREF` set[1][2] but the IPv6-specific flag `RT6_LOOKUP_F_DST_NOREF` might not be, leading to `fib6_rule_suppress` not decreasing the refcount when needed. How to reproduce: - Add the following nftables rule to a prerouting chain: meta nfproto ipv6 fib saddr . mark . iif oif missing drop This can be done with: sudo nft create table inet test sudo nft create chain inet test test_chain '{ type filter hook prerouting priority filter + 10; policy accept; }' sudo nft add rule inet test test_chain meta nfproto ipv6 fib saddr . mark . iif oif missing drop - Run: sudo ip -6 rule add table main suppress_prefixlength 0 - Watch `sudo slabtop -o | grep ip6_dst_cache` to see memory usage increase with every incoming ipv6 packet. This patch exposes the protocol-specific flags to the protocol specific `suppress` function, and check the protocol-specific `flags` argument for RT6_LOOKUP_F_DST_NOREF instead of the generic FIB_LOOKUP_NOREF when decreasing the refcount, like this. [1]: https://github.com/torvalds/linux/blob/ca7a03c4175366a92cee0ccc4fec0038c3266e26/net/ipv6/fib6_rules.c#L71 [2]: https://github.com/torvalds/linux/blob/ca7a03c4175366a92cee0ccc4fec0038c3266e26/net/ipv6/fib6_rules.c#L99 Link: https://bugzilla.kernel.org/show_bug.cgi?id=215105 Fixes: ca7a03c41753 ("ipv6: do not free rt if FIB_LOOKUP_NOREF is set on suppress rule") Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08net: return correct error codeliuguoqiang1-1/+1
[ Upstream commit 6def480181f15f6d9ec812bca8cbc62451ba314c ] When kmemdup called failed and register_net_sysctl return NULL, should return ENOMEM instead of ENOBUFS Signed-off-by: liuguoqiang <liuguoqiang@uniontech.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01tcp: correctly handle increased zerocopy args struct sizeArjun Roy1-2/+2
[ Upstream commit e0fecb289ad3fd2245cdc50bf450b97fcca39884 ] A prior patch increased the size of struct tcp_zerocopy_receive but did not update do_tcp_getsockopt() handling to properly account for this. This patch simply reintroduces content erroneously cut from the referenced prior patch that handles the new struct size. Fixes: 18fb76ed5386 ("net-zerocopy: Copy straggler unaligned data for TCP Rx. zerocopy.") Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01tcp_cubic: fix spurious Hystart ACK train detections for not-cwnd-limited flowsEric Dumazet1-2/+3
[ Upstream commit 4e1fddc98d2585ddd4792b5e44433dcee7ece001 ] While testing BIG TCP patch series, I was expecting that TCP_RR workloads with 80KB requests/answers would send one 80KB TSO packet, then being received as a single GRO packet. It turns out this was not happening, and the root cause was that cubic Hystart ACK train was triggering after a few (2 or 3) rounds of RPC. Hystart was wrongly setting CWND/SSTHRESH to 30, while my RPC needed a budget of ~20 segments. Ideally these TCP_RR flows should not exit slow start. Cubic Hystart should reset itself at each round, instead of assuming every TCP flow is a bulk one. Note that even after this patch, Hystart can still trigger, depending on scheduling artifacts, but at a higher CWND/SSTHRESH threshold, keeping optimal TSO packet sizes. Tested: ip link set dev eth0 gro_ipv6_max_size 131072 gso_ipv6_max_size 131072 nstat -n; netperf -H ... -t TCP_RR -l 5 -- -r 80000,80000 -K cubic; nstat|egrep "Ip6InReceives|Hystart|Ip6OutRequests" Before: 8605 Ip6InReceives 87541 0.0 Ip6OutRequests 129496 0.0 TcpExtTCPHystartTrainDetect 1 0.0 TcpExtTCPHystartTrainCwnd 30 0.0 After: 8760 Ip6InReceives 88514 0.0 Ip6OutRequests 87975 0.0 Fixes: ae27e98a5152 ("[TCP] CUBIC v2.3") Co-developed-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Yuchung Cheng <ycheng@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Link: https://lore.kernel.org/r/20211123202535.1843771-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01net: nexthop: release IPv6 per-cpu dsts when replacing a nexthop groupNikolay Aleksandrov1-2/+23
[ Upstream commit 1005f19b9357b81aa64e1decd08d6e332caaa284 ] When replacing a nexthop group, we must release the IPv6 per-cpu dsts of the removed nexthop entries after an RCU grace period because they contain references to the nexthop's net device and to the fib6 info. With specific series of events[1] we can reach net device refcount imbalance which is unrecoverable. IPv4 is not affected because dsts don't take a refcount on the route. [1] $ ip nexthop list id 200 via 2002:db8::2 dev bridge.10 scope link onlink id 201 via 2002:db8::3 dev bridge scope link onlink id 203 group 201/200 $ ip -6 route 2001:db8::10 nhid 203 metric 1024 pref medium nexthop via 2002:db8::3 dev bridge weight 1 onlink nexthop via 2002:db8::2 dev bridge.10 weight 1 onlink Create rt6_info through one of the multipath legs, e.g.: $ taskset -a -c 1 ./pkt_inj 24 bridge.10 2001:db8::10 (pkt_inj is just a custom packet generator, nothing special) Then remove that leg from the group by replace (let's assume it is id 200 in this case): $ ip nexthop replace id 203 group 201 Now remove the IPv6 route: $ ip -6 route del 2001:db8::10/128 The route won't be really deleted due to the stale rt6_info holding 1 refcnt in nexthop id 200. At this point we have the following reference count dependency: (deleted) IPv6 route holds 1 reference over nhid 203 nh 203 holds 1 ref over id 201 nh 200 holds 1 ref over the net device and the route due to the stale rt6_info Now to create circular dependency between nh 200 and the IPv6 route, and also to get a reference over nh 200, restore nhid 200 in the group: $ ip nexthop replace id 203 group 201/200 And now we have a permanent circular dependncy because nhid 203 holds a reference over nh 200 and 201, but the route holds a ref over nh 203 and is deleted. To trigger the bug just delete the group (nhid 203): $ ip nexthop del id 203 It won't really be deleted due to the IPv6 route dependency, and now we have 2 unlinked and deleted objects that reference each other: the group and the IPv6 route. Since the group drops the reference it holds over its entries at free time (i.e. its own refcount needs to drop to 0) that will never happen and we get a permanent ref on them, since one of the entries holds a reference over the IPv6 route it will also never be released. At this point the dependencies are: (deleted, only unlinked) IPv6 route holds reference over group nh 203 (deleted, only unlinked) group nh 203 holds reference over nh 201 and 200 nh 200 holds 1 ref over the net device and the route due to the stale rt6_info This is the last point where it can be fixed by running traffic through nh 200, and specifically through the same CPU so the rt6_info (dst) will get released due to the IPv6 genid, that in turn will free the IPv6 route, which in turn will free the ref count over the group nh 203. If nh 200 is deleted at this point, it will never be released due to the ref from the unlinked group 203, it will only be unlinked: $ ip nexthop del id 200 $ ip nexthop $ Now we can never release that stale rt6_info, we have IPv6 route with ref over group nh 203, group nh 203 with ref over nh 200 and 201, nh 200 with rt6_info (dst) with ref over the net device and the IPv6 route. All of these objects are only unlinked, and cannot be released, thus they can't release their ref counts. Message from syslogd@dev at Nov 19 14:04:10 ... kernel:[73501.828730] unregister_netdevice: waiting for bridge.10 to become free. Usage count = 3 Message from syslogd@dev at Nov 19 14:04:20 ... kernel:[73512.068811] unregister_netdevice: waiting for bridge.10 to become free. Usage count = 3 Fixes: 7bf4796dd099 ("nexthops: add support for replace") Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01net: nexthop: fix null pointer dereference when IPv6 is not enabledNikolay Aleksandrov1-3/+7
commit 1c743127cc54b112b155f434756bd4b5fa565a99 upstream. When we try to add an IPv6 nexthop and IPv6 is not enabled (!CONFIG_IPV6) we'll hit a NULL pointer dereference[1] in the error path of nh_create_ipv6() due to calling ipv6_stub->fib6_nh_release. The bug has been present since the beginning of IPv6 nexthop gateway support. Commit 1aefd3de7bc6 ("ipv6: Add fib6_nh_init and release to stubs") tells us that only fib6_nh_init has a dummy stub because fib6_nh_release should not be called if fib6_nh_init returns an error, but the commit below added a call to ipv6_stub->fib6_nh_release in its error path. To fix it return the dummy stub's -EAFNOSUPPORT error directly without calling ipv6_stub->fib6_nh_release in nh_create_ipv6()'s error path. [1] Output is a bit truncated, but it clearly shows the error. BUG: kernel NULL pointer dereference, address: 000000000000000000 #PF: supervisor instruction fetch in kernel modede #PF: error_code(0x0010) - not-present pagege PGD 0 P4D 0 Oops: 0010 [#1] PREEMPT SMP NOPTI CPU: 4 PID: 638 Comm: ip Kdump: loaded Not tainted 5.16.0-rc1+ #446 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014 RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffff888109f5b8f0 EFLAGS: 00010286^Ac RAX: 0000000000000000 RBX: ffff888109f5ba28 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881008a2860 RBP: ffff888109f5b9d8 R08: 0000000000000000 R09: 0000000000000000 R10: ffff888109f5b978 R11: ffff888109f5b948 R12: 00000000ffffff9f R13: ffff8881008a2a80 R14: ffff8881008a2860 R15: ffff8881008a2840 FS: 00007f98de70f100(0000) GS:ffff88822bf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000100efc000 CR4: 00000000000006e0 Call Trace: <TASK> nh_create_ipv6+0xed/0x10c rtm_new_nexthop+0x6d7/0x13f3 ? check_preemption_disabled+0x3d/0xf2 ? lock_is_held_type+0xbe/0xfd rtnetlink_rcv_msg+0x23f/0x26a ? check_preemption_disabled+0x3d/0xf2 ? rtnl_calcit.isra.0+0x147/0x147 netlink_rcv_skb+0x61/0xb2 netlink_unicast+0x100/0x187 netlink_sendmsg+0x37f/0x3a0 ? netlink_unicast+0x187/0x187 sock_sendmsg_nosec+0x67/0x9b ____sys_sendmsg+0x19d/0x1f9 ? copy_msghdr_from_user+0x4c/0x5e ? rcu_read_lock_any_held+0x2a/0x78 ___sys_sendmsg+0x6c/0x8c ? asm_sysvec_apic_timer_interrupt+0x12/0x20 ? lockdep_hardirqs_on+0xd9/0x102 ? sockfd_lookup_light+0x69/0x99 __sys_sendmsg+0x50/0x6e do_syscall_64+0xcb/0xf2 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f98dea28914 Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b5 0f 1f 80 00 00 00 00 48 8d 05 e9 5d 0c 00 8b 00 85 c0 75 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 41 54 41 89 d4 55 48 89 f5 53 RSP: 002b:00007fff859f5e68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e2e RAX: ffffffffffffffda RBX: 00000000619cb810 RCX: 00007f98dea28914 RDX: 0000000000000000 RSI: 00007fff859f5ed0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000008 R10: fffffffffffffce6 R11: 0000000000000246 R12: 0000000000000001 R13: 000055c0097ae520 R14: 000055c0097957fd R15: 00007fff859f63a0 </TASK> Modules linked in: bridge stp llc bonding virtio_net Cc: stable@vger.kernel.org Fixes: 53010f991a9f ("nexthop: Add support for IPv6 gateways") Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26tcp: Fix uninitialized access in skb frags array for Rx 0cp.Arjun Roy1-0/+3
[ Upstream commit 70701b83e208767f2720d8cd3e6a62cddafb3a30 ] TCP Receive zerocopy iterates through the SKB queue via tcp_recv_skb(), acquiring a pointer to an SKB and an offset within that SKB to read from. From there, it iterates the SKB frags array to determine which offset to start remapping pages from. However, this is built on the assumption that the offset read so far within the SKB is smaller than the SKB length. If this assumption is violated, we can attempt to read an invalid frags array element, which would cause a fault. tcp_recv_skb() can cause such an SKB to be returned when the TCP FIN flag is set. Therefore, we must guard against this occurrence inside skb_advance_frag(). One way that we can reproduce this error follows: 1) In a receiver program, call getsockopt(TCP_ZEROCOPY_RECEIVE) with: char some_array[32 * 1024]; struct tcp_zerocopy_receive zc = { .copybuf_address = (__u64) &some_array[0], .copybuf_len = 32 * 1024, }; 2) In a sender program, after a TCP handshake, send the following sequence of packets: i) Seq = [X, X+4000] ii) Seq = [X+4000, X+5000] iii) Seq = [X+4000, X+5000], Flags = FIN | URG, urgptr=1000 (This can happen without URG, if we have a signal pending, but URG is a convenient way to reproduce the behaviour). In this case, the following event sequence will occur on the receiver: tcp_zerocopy_receive(): -> receive_fallback_to_copy() // copybuf_len >= inq -> tcp_recvmsg_locked() // reads 5000 bytes, then breaks due to URG -> tcp_recv_skb() // yields skb with skb->len == offset -> tcp_zerocopy_set_hint_for_skb() -> skb_advance_to_frag() // will returns a frags ptr. >= nr_frags -> find_next_mappable_frag() // will dereference this bad frags ptr. With this patch, skb_advance_to_frag() will no longer return an invalid frags pointer, and will return NULL instead, fixing the issue. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: 05255b823a61 ("tcp: add TCP_ZEROCOPY_RECEIVE support for zerocopy receive") Link: https://lore.kernel.org/r/20211111235215.2605384-1-arjunroy.kdev@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-26net-zerocopy: Refactor skb frag fast-forward op.Arjun Roy1-9/+26
[ Upstream commit 7fba5309efe24e4f0284ef4b8663cdf401035e72 ] Refactor skb frag fast-forwarding for tcp receive zerocopy. This is part of a patch set that introduces short-circuited hybrid copies for small receive operations, which results in roughly 33% fewer syscalls for small RPC scenarios. skb_advance_to_frag(), given a skb and an offset into the skb, iterates from the first frag for the skb until we're at the frag specified by the offset. Assuming the offset provided refers to how many bytes in the skb are already read, the returned frag points to the next frag we may read from, while offset_frag is set to the number of bytes from this frag that we have already read. If frag is not null and offset_frag is equal to 0, then we may be able to map this frag's page into the process address space with vm_insert_page(). However, if offset_frag is not equal to 0, then we cannot do so. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-26net-zerocopy: Copy straggler unaligned data for TCP Rx. zerocopy.Arjun Roy1-16/+68
[ Upstream commit 18fb76ed53865c1b5d5f0157b1b825704590beb5 ] When TCP receive zerocopy does not successfully map the entire requested space, it outputs a 'hint' that the caller should recvmsg(). Augment zerocopy to accept a user buffer that it tries to copy this hint into - if it is possible to copy the entire hint, it will do so. This elides a recvmsg() call for received traffic that isn't exactly page-aligned in size. This was tested with RPC-style traffic of arbitrary sizes. Normally, each received message required at least one getsockopt() call, and one recvmsg() call for the remaining unaligned data. With this change, almost all of the recvmsg() calls are eliminated, leading to a savings of about 25%-50% in number of system calls for RPC-style workloads. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18bpf, sockmap: Remove unhash handler for BPF sockmap usageJohn Fastabend1-1/+0
[ Upstream commit b8b8315e39ffaca82e79d86dde26e9144addf66b ] We do not need to handle unhash from BPF side we can simply wait for the close to happen. The original concern was a socket could transition from ESTABLISHED state to a new state while the BPF hook was still attached. But, we convinced ourself this is no longer possible and we also improved BPF sockmap to handle listen sockets so this is no longer a problem. More importantly though there are cases where unhash is called when data is in the receive queue. The BPF unhash logic will flush this data which is wrong. To be correct it should keep the data in the receive queue and allow a receiving application to continue reading the data. This may happen when tcp_abort() is received for example. Instead of complicating the logic in unhash simply moving all this to tcp_close() hook solves this. Fixes: 51199405f9672 ("bpf: skb_verdict, support SK_PASS on RX BPF path") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Jussi Maki <joamaki@gmail.com> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/20211103204736.248403-3-john.fastabend@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18tcp: don't free a FIN sk_buff in tcp_remove_empty_skb()Jon Maxwell1-1/+1
[ Upstream commit cf12e6f9124629b18a6182deefc0315f0a73a199 ] v1: Implement a more general statement as recommended by Eric Dumazet. The sequence number will be advanced, so this check will fix the FIN case and other cases. A customer reported sockets stuck in the CLOSING state. A Vmcore revealed that the write_queue was not empty as determined by tcp_write_queue_empty() but the sk_buff containing the FIN flag had been freed and the socket was zombied in that state. Corresponding pcaps show no FIN from the Linux kernel on the wire. Some instrumentation was added to the kernel and it was found that there is a timing window where tcp_sendmsg() can run after tcp_send_fin(). tcp_sendmsg() will hit an error, for example: 1269 ▹ if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))↩ 1270 ▹ ▹ goto do_error;↩ tcp_remove_empty_skb() will then free the FIN sk_buff as "skb->len == 0". The TCP socket is now wedged in the FIN-WAIT-1 state because the FIN is never sent. If the other side sends a FIN packet the socket will transition to CLOSING and remain that way until the system is rebooted. Fix this by checking for the FIN flag in the sk_buff and don't free it if that is the case. Testing confirmed that fixed the issue. Fixes: fdfc5c8594c2 ("tcp: remove empty skb from write queue in error cases") Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com> Reported-by: Monir Zouaoui <Monir.Zouaoui@mail.schwarz> Reported-by: Simon Stier <simon.stier@mail.schwarz> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18tcp: switch orphan_count to bare per-cpu countersEric Dumazet4-9/+37
[ Upstream commit 19757cebf0c5016a1f36f7fe9810a9f0b33c0832 ] Use of percpu_counter structure to track count of orphaned sockets is causing problems on modern hosts with 256 cpus or more. Stefan Bach reported a serious spinlock contention in real workloads, that I was able to reproduce with a netfilter rule dropping incoming FIN packets. 53.56% server [kernel.kallsyms] [k] queued_spin_lock_slowpath | ---queued_spin_lock_slowpath | --53.51%--_raw_spin_lock_irqsave | --53.51%--__percpu_counter_sum tcp_check_oom | |--39.03%--__tcp_close | tcp_close | inet_release | inet6_release | sock_close | __fput | ____fput | task_work_run | exit_to_usermode_loop | do_syscall_64 | entry_SYSCALL_64_after_hwframe | __GI___libc_close | --14.48%--tcp_out_of_resources tcp_write_timeout tcp_retransmit_timer tcp_write_timer_handler tcp_write_timer call_timer_fn expire_timers __run_timers run_timer_softirq __softirqentry_text_start As explained in commit cf86a086a180 ("net/dst: use a smaller percpu_counter batch for dst entries accounting"), default batch size is too big for the default value of tcp_max_orphans (262144). But even if we reduce batch sizes, there would still be cases where the estimated count of orphans is beyond the limit, and where tcp_too_many_orphans() has to call the expensive percpu_counter_sum_positive(). One solution is to use plain per-cpu counters, and have a timer to periodically refresh this cache. Updating this cache every 100ms seems about right, tcp pressure state is not radically changing over shorter periods. percpu_counter was nice 15 years ago while hosts had less than 16 cpus, not anymore by current standards. v2: Fix the build issue for CONFIG_CRYPTO_DEV_CHELSIO_TLS=m, reported by kernel test robot <lkp@intel.com> Remove unused socket argument from tcp_too_many_orphans() Fixes: dd24c00191d5 ("net: Use a percpu_counter for orphan_count") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Stefan Bach <sfb@google.com> Cc: Neal Cardwell <ncardwell@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-02tcp_bpf: Fix one concurrency problem in the tcp_bpf_send_verdict functionLiu Jian1-0/+12
commit cd9733f5d75c94a32544d6ce5be47e14194cf137 upstream. With two Msgs, msgA and msgB and a user doing nonblocking sendmsg calls (or multiple cores) on a single socket 'sk' we could get the following flow. msgA, sk msgB, sk ----------- --------------- tcp_bpf_sendmsg() lock(sk) psock = sk->psock tcp_bpf_sendmsg() lock(sk) ... blocking tcp_bpf_send_verdict if (psock->eval == NONE) psock->eval = sk_psock_msg_verdict .. < handle SK_REDIRECT case > release_sock(sk) < lock dropped so grab here > ret = tcp_bpf_sendmsg_redir psock = sk->psock tcp_bpf_send_verdict lock_sock(sk) ... blocking on B if (psock->eval == NONE) <- boom. psock->eval will have msgA state The problem here is we dropped the lock on msgA and grabbed it with msgB. Now we have old state in psock and importantly psock->eval has not been cleared. So msgB will run whatever action was done on A and the verdict program may never see it. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: Liu Jian <liujian56@huawei.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20211012052019.184398-1-liujian56@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-27tcp: md5: Fix overlap between vrf and non-vrf keysLeonard Crestez1-3/+16
[ Upstream commit 86f1e3a8489f6a0232c1f3bc2bdb379f5ccdecec ] With net.ipv4.tcp_l3mdev_accept=1 it is possible for a listen socket to accept connection from the same client address in different VRFs. It is also possible to set different MD5 keys for these clients which differ only in the tcpm_l3index field. This appears to work when distinguishing between different VRFs but not between non-VRF and VRF connections. In particular: * tcp_md5_do_lookup_exact will match a non-vrf key against a vrf key. This means that adding a key with l3index != 0 after a key with l3index == 0 will cause the earlier key to be deleted. Both keys can be present if the non-vrf key is added later. * _tcp_md5_do_lookup can match a non-vrf key before a vrf key. This casues failures if the passwords differ. Fix this by making tcp_md5_do_lookup_exact perform an actual exact comparison on l3index and by making __tcp_md5_do_lookup perfer vrf-bound keys above other considerations like prefixlen. Fixes: dea53bb80e07 ("tcp: Add l3index to tcp_md5sig_key and md5 functions") Signed-off-by: Leonard Crestez <cdleonard@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-13net: prefer socket bound to interface when not in VRFMike Manning2-2/+5
[ Upstream commit 8d6c414cd2fb74aa6812e9bfec6178f8246c4f3a ] The commit 6da5b0f027a8 ("net: ensure unbound datagram socket to be chosen when not in a VRF") modified compute_score() so that a device match is always made, not just in the case of an l3mdev skb, then increments the score also for unbound sockets. This ensures that sockets bound to an l3mdev are never selected when not in a VRF. But as unbound and bound sockets are now scored equally, this results in the last opened socket being selected if there are matches in the default VRF for an unbound socket and a socket bound to a dev that is not an l3mdev. However, handling prior to this commit was to always select the bound socket in this case. Reinstate this handling by incrementing the score only for bound sockets. The required isolation due to choosing between an unbound socket and a socket bound to an l3mdev remains in place due to the device match always being made. The same approach is taken for compute_score() for stream sockets. Fixes: 6da5b0f027a8 ("net: ensure unbound datagram socket to be chosen when not in a VRF") Fixes: e78190581aff ("net: ensure unbound stream socket to be chosen when not in a VRF") Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/cf0a8523-b362-1edf-ee78-eef63cbbb428@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-06net: udp: annotate data race around udp_sk(sk)->corkflagEric Dumazet1-5/+5
commit a9f5970767d11eadc805d5283f202612c7ba1f59 upstream. up->corkflag field can be read or written without any lock. Annotate accesses to avoid possible syzbot/KCSAN reports. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06net: ipv4: Fix rtnexthop len when RTA_FLOW is presentXiao Liang1-7/+9
[ Upstream commit 597aa16c782496bf74c5dc3b45ff472ade6cee64 ] Multipath RTA_FLOW is embedded in nexthop. Dump it in fib_add_nexthop() to get the length of rtnexthop correct. Fixes: b0f60193632e ("ipv4: Refactor nexthop attributes in fib_dump_info") Signed-off-by: Xiao Liang <shaw.leon@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22ip_gre: validate csum_start only on pullWillem de Bruijn1-3/+6
[ Upstream commit 8a0ed250f911da31a2aef52101bc707846a800ff ] The GRE tunnel device can pull existing outer headers in ipge_xmit. This is a rare path, apparently unique to this device. The below commit ensured that pulling does not move skb->data beyond csum_start. But it has a false positive if ip_summed is not CHECKSUM_PARTIAL and thus csum_start is irrelevant. Refine to exclude this. At the same time simplify and strengthen the test. Simplify, by moving the check next to the offending pull, making it more self documenting and removing an unnecessary branch from other code paths. Strengthen, by also ensuring that the transport header is correct and therefore the inner headers will be after skb_reset_inner_headers. The transport header is set to csum_start in skb_partial_csum_set. Link: https://lore.kernel.org/netdev/YS+h%2FtqCJJiQei+W@shredder/ Fixes: 1d011c4803c7 ("ip_gre: add validation for csum_start") Reported-by: Ido Schimmel <idosch@idosch.org> Suggested-by: Alexander Duyck <alexander.duyck@gmail.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22Set fc_nlinfo in nh_create_ipv4, nh_create_ipv6Ryoga Saito1-0/+2
[ Upstream commit 9aca491e0dccf8a9d84a5b478e5eee3c6ea7803b ] This patch fixes kernel NULL pointer dereference when creating nexthop which is bound with SRv6 decapsulation. In the creation of nexthop, __seg6_end_dt_vrf_build is called. __seg6_end_dt_vrf_build expects fc_lninfo in fib6_config is set correctly, but it isn't set in nh_create_ipv6, which causes kernel crash. Here is steps to reproduce kernel crash: 1. modprobe vrf 2. ip -6 nexthop add encap seg6local action End.DT4 vrftable 1 dev eth0 We got the following message: [ 901.370336] BUG: kernel NULL pointer dereference, address: 0000000000000ba0 [ 901.371658] #PF: supervisor read access in kernel mode [ 901.372672] #PF: error_code(0x0000) - not-present page [ 901.373672] PGD 0 P4D 0 [ 901.374248] Oops: 0000 [#1] SMP PTI [ 901.374944] CPU: 0 PID: 8593 Comm: ip Not tainted 5.14-051400-generic #202108310811-Ubuntu [ 901.376404] Hardware name: Red Hat KVM, BIOS 1.11.1-4.module_el8.2.0+320+13f867d7 04/01/2014 [ 901.377907] RIP: 0010:vrf_ifindex_lookup_by_table_id+0x19/0x90 [vrf] [ 901.379182] Code: c1 e9 72 ff ff ff e8 96 49 01 c2 66 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 89 f5 41 54 53 8b 05 47 4c 00 00 <48> 8b 97 a0 0b 00 00 48 8b 1c c2 e8 57 27 53 c1 4c 8d a3 88 00 00 [ 901.382652] RSP: 0018:ffffbf2d02043590 EFLAGS: 00010282 [ 901.383746] RAX: 000000000000000b RBX: ffff990808255e70 RCX: ffffbf2d02043aa8 [ 901.385436] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000000 [ 901.386924] RBP: ffffbf2d020435b0 R08: 00000000000000c0 R09: ffff990808255e40 [ 901.388537] R10: ffffffff83b08c90 R11: 0000000000000009 R12: 0000000000000000 [ 901.389937] R13: 0000000000000001 R14: 0000000000000000 R15: 000000000000000b [ 901.391226] FS: 00007fe49381f740(0000) GS:ffff99087dc00000(0000) knlGS:0000000000000000 [ 901.392737] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 901.393803] CR2: 0000000000000ba0 CR3: 000000000e3e8003 CR4: 0000000000770ef0 [ 901.395122] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 901.396496] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 901.397833] PKRU: 55555554 [ 901.398578] Call Trace: [ 901.399144] l3mdev_ifindex_lookup_by_table_id+0x3b/0x70 [ 901.400179] __seg6_end_dt_vrf_build+0x34/0xd0 [ 901.401067] seg6_end_dt4_build+0x16/0x20 [ 901.401904] seg6_local_build_state+0x271/0x430 [ 901.402797] lwtunnel_build_state+0x81/0x130 [ 901.403645] fib_nh_common_init+0x82/0x100 [ 901.404465] ? sock_def_readable+0x4b/0x80 [ 901.405285] fib6_nh_init+0x115/0x7c0 [ 901.406033] nh_create_ipv6.isra.0+0xe1/0x140 [ 901.406932] rtm_new_nexthop+0x3b7/0xeb0 [ 901.407828] rtnetlink_rcv_msg+0x152/0x3a0 [ 901.408663] ? rtnl_calcit.isra.0+0x130/0x130 [ 901.409535] netlink_rcv_skb+0x55/0x100 [ 901.410319] rtnetlink_rcv+0x15/0x20 [ 901.411026] netlink_unicast+0x1a8/0x250 [ 901.411813] netlink_sendmsg+0x238/0x470 [ 901.412602] ? _copy_from_user+0x2b/0x60 [ 901.413394] sock_sendmsg+0x65/0x70 [ 901.414112] ____sys_sendmsg+0x218/0x290 [ 901.414929] ? copy_msghdr_from_user+0x5c/0x90 [ 901.415814] ___sys_sendmsg+0x81/0xc0 [ 901.416559] ? fsnotify_destroy_marks+0x27/0xf0 [ 901.417447] ? call_rcu+0xa4/0x230 [ 901.418153] ? kmem_cache_free+0x23f/0x410 [ 901.418972] ? dentry_free+0x37/0x70 [ 901.419705] ? mntput_no_expire+0x4c/0x260 [ 901.420574] __sys_sendmsg+0x62/0xb0 [ 901.421297] __x64_sys_sendmsg+0x1f/0x30 [ 901.422057] do_syscall_64+0x5c/0xc0 [ 901.422756] ? syscall_exit_to_user_mode+0x27/0x50 [ 901.423675] ? __x64_sys_close+0x12/0x40 [ 901.424462] ? do_syscall_64+0x69/0xc0 [ 901.425219] ? irqentry_exit_to_user_mode+0x9/0x20 [ 901.426149] ? irqentry_exit+0x19/0x30 [ 901.426901] ? exc_page_fault+0x89/0x160 [ 901.427709] ? asm_exc_page_fault+0x8/0x30 [ 901.428536] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 901.429514] RIP: 0033:0x7fe493945747 [ 901.430248] Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10 [ 901.433549] RSP: 002b:00007ffe9932cf68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 901.434981] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe493945747 [ 901.436303] RDX: 0000000000000000 RSI: 00007ffe9932cfe0 RDI: 0000000000000003 [ 901.437607] RBP: 00000000613053f7 R08: 0000000000000001 R09: 00007ffe9932d07c [ 901.438990] R10: 000055f4a903a010 R11: 0000000000000246 R12: 0000000000000001 [ 901.440340] R13: 0000000000000001 R14: 000055f4a802b163 R15: 000055f4a8042020 [ 901.441630] Modules linked in: vrf nls_utf8 isofs nls_iso8859_1 dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua intel_rapl_msr intel_rapl_common isst_if_mbox_msr isst_if_common nfit rapl input_leds joydev serio_raw qemu_fw_cfg mac_hid sch_fq_codel drm virtio_rng ip_tables x_tables autofs4 btrfs blake2b_generic zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel crypto_simd virtio_net net_failover cryptd psmouse virtio_blk failover i2c_piix4 pata_acpi floppy [ 901.450808] CR2: 0000000000000ba0 [ 901.451514] ---[ end trace c27b934b99ade304 ]--- [ 901.452403] RIP: 0010:vrf_ifindex_lookup_by_table_id+0x19/0x90 [vrf] [ 901.453626] Code: c1 e9 72 ff ff ff e8 96 49 01 c2 66 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 89 f5 41 54 53 8b 05 47 4c 00 00 <48> 8b 97 a0 0b 00 00 48 8b 1c c2 e8 57 27 53 c1 4c 8d a3 88 00 00 [ 901.456910] RSP: 0018:ffffbf2d02043590 EFLAGS: 00010282 [ 901.457912] RAX: 000000000000000b RBX: ffff990808255e70 RCX: ffffbf2d02043aa8 [ 901.459238] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000000 [ 901.460552] RBP: ffffbf2d020435b0 R08: 00000000000000c0 R09: ffff990808255e40 [ 901.461882] R10: ffffffff83b08c90 R11: 0000000000000009 R12: 0000000000000000 [ 901.463208] R13: 0000000000000001 R14: 0000000000000000 R15: 000000000000000b [ 901.464529] FS: 00007fe49381f740(0000) GS:ffff99087dc00000(0000) knlGS:0000000000000000 [ 901.466058] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 901.467189] CR2: 0000000000000ba0 CR3: 000000000e3e8003 CR4: 0000000000770ef0 [ 901.468515] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 901.469858] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 901.471139] PKRU: 55555554 Signed-off-by: Ryoga Saito <contact@proelbtn.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22udp_tunnel: Fix udp_tunnel_nic work-queue typeAya Levin1-1/+1
commit e50e711351bdc656a8e6ca1022b4293cae8dcd59 upstream. Turn udp_tunnel_nic work-queue to an ordered work-queue. This queue holds the UDP-tunnel configuration commands of the different netdevs. When the netdevs are functions of the same NIC the order of execution may be crucial. Problem example: NIC with 2 PFs, both PFs declare offload quota of up to 3 UDP-ports. $ifconfig eth2 1.1.1.1/16 up $ip link add eth2_19503 type vxlan id 5049 remote 1.1.1.2 dev eth2 dstport 19053 $ip link set dev eth2_19503 up $ip link add eth2_19504 type vxlan id 5049 remote 1.1.1.3 dev eth2 dstport 19054 $ip link set dev eth2_19504 up $ip link add eth2_19505 type vxlan id 5049 remote 1.1.1.4 dev eth2 dstport 19055 $ip link set dev eth2_19505 up $ip link add eth2_19506 type vxlan id 5049 remote 1.1.1.5 dev eth2 dstport 19056 $ip link set dev eth2_19506 up NIC RX port offload infrastructure offloads the first 3 UDP-ports (on all devices which sets NETIF_F_RX_UDP_TUNNEL_PORT feature) and not UDP-port 19056. So both PFs gets this offload configuration. $ip link set dev eth2_19504 down This triggers udp-tunnel-core to remove the UDP-port 19504 from offload-ports-list and offload UDP-port 19056 instead. In this scenario it is important that the UDP-port of 19504 will be removed from both PFs before trying to add UDP-port 19056. The NIC can stop offloading a UDP-port only when all references are removed. Otherwise the NIC may report exceeding of the offload quota. Fixes: cc4e3835eff4 ("udp_tunnel: add central NIC RX port offload infrastructure") Signed-off-by: Aya Levin <ayal@nvidia.com> Reviewed-by: Tariq Toukan <tariqt@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22tcp: fix tp->undo_retrans accounting in tcp_sacktag_one()zhenggy1-1/+1
commit 4f884f3962767877d7aabbc1ec124d2c307a4257 upstream. Commit 10d3be569243 ("tcp-tso: do not split TSO packets at retransmit time") may directly retrans a multiple segments TSO/GSO packet without split, Since this commit, we can no longer assume that a retransmitted packet is a single segment. This patch fixes the tp->undo_retrans accounting in tcp_sacktag_one() that use the actual segments(pcount) of the retransmitted packet. Before that commit (10d3be569243), the assumption underlying the tp->undo_retrans-- seems correct. Fixes: 10d3be569243 ("tcp-tso: do not split TSO packets at retransmit time") Signed-off-by: zhenggy <zhenggy@chinatelecom.cn> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-18tcp: enable data-less, empty-cookie SYN with TFO_SERVER_COOKIE_NOT_REQDLuke Hsiao1-2/+1
[ Upstream commit e3faa49bcecdfcc80e94dd75709d6acb1a5d89f6 ] Since the original TFO server code was implemented in commit 168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef ("tcp: TCP Fast Open Server - main code path") the TFO server code has supported the sysctl bit flag TFO_SERVER_COOKIE_NOT_REQD. Currently, when the TFO_SERVER_ENABLE and TFO_SERVER_COOKIE_NOT_REQD sysctl bit flags are set, a server connection will accept a SYN with N bytes of data (N > 0) that has no TFO cookie, create a new fast open connection, process the incoming data in the SYN, and make the connection ready for accepting. After accepting, the connection is ready for read()/recvmsg() to read the N bytes of data in the SYN, ready for write()/sendmsg() calls and data transmissions to transmit data. This commit changes an edge case in this feature by changing this behavior to apply to (N >= 0) bytes of data in the SYN rather than only (N > 0) bytes of data in the SYN. Now, a server will accept a data-less SYN without a TFO cookie if TFO_SERVER_COOKIE_NOT_REQD is set. Caveat! While this enables a new kind of TFO (data-less empty-cookie SYN), some firewall rules setup may not work if they assume such packets are not legit TFOs and will filter them. Signed-off-by: Luke Hsiao <lukehsiao@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20210816205105.2533289-1-luke.w.hsiao@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-18ipv4: ip_output.c: Fix out-of-bounds warning in ip_copy_addrs()Gustavo A. R. Silva1-2/+3
[ Upstream commit 6321c7acb82872ef6576c520b0e178eaad3a25c0 ] Fix the following out-of-bounds warning: In function 'ip_copy_addrs', inlined from '__ip_queue_xmit' at net/ipv4/ip_output.c:517:2: net/ipv4/ip_output.c:449:2: warning: 'memcpy' offset [40, 43] from the object at 'fl' is out of the bounds of referenced subobject 'saddr' with type 'unsigned int' at offset 36 [-Warray-bounds] 449 | memcpy(&iph->saddr, &fl4->saddr, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 450 | sizeof(fl4->saddr) + sizeof(fl4->daddr)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The problem is that the original code is trying to copy data into a couple of struct members adjacent to each other in a single call to memcpy(). This causes a legitimate compiler warning because memcpy() overruns the length of &iph->saddr and &fl4->saddr. As these are just a couple of struct members, fix this by using direct assignments, instead of memcpy(). This helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy(). Link: https://github.com/KSPP/linux/issues/109 Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/lkml/d5ae2e65-1f18-2577-246f-bada7eee6ccd@intel.com/ Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15ipv4: fix endianness issue in inet_rtm_getroute_build_skb()Eric Dumazet1-1/+1
[ Upstream commit 92548b0ee220e000d81c27ac9a80e0ede895a881 ] The UDP length field should be in network order. This removes the following sparse error: net/ipv4/route.c:3173:27: warning: incorrect type in assignment (different base types) net/ipv4/route.c:3173:27: expected restricted __be16 [usertype] len net/ipv4/route.c:3173:27: got unsigned long Fixes: 404eb77ea766 ("ipv4: support sport, dport and ip_proto in RTM_GETROUTE") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Roopa Prabhu <roopa@nvidia.com> Cc: David Ahern <dsahern@kernel.org> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15ipv4: make exception cache less predictibleEric Dumazet1-16/+30
[ Upstream commit 67d6d681e15b578c1725bad8ad079e05d1c48a8e ] Even after commit 6457378fe796 ("ipv4: use siphash instead of Jenkins in fnhe_hashfun()"), an attacker can still use brute force to learn some secrets from a victim linux host. One way to defeat these attacks is to make the max depth of the hash table bucket a random value. Before this patch, each bucket of the hash table used to store exceptions could contain 6 items under attack. After the patch, each bucket would contains a random number of items, between 6 and 10. The attacker can no longer infer secrets. This is slightly increasing memory size used by the hash table, by 50% in average, we do not expect this to be a problem. This patch is more complex than the prior one (IPv6 equivalent), because IPv4 was reusing the oldest entry. Since we need to be able to evict more than one entry per update_or_create_fnhe() call, I had to replace fnhe_oldest() with fnhe_remove_oldest(). Also note that we will queue extra kfree_rcu() calls under stress, which hopefully wont be a too big issue. Fixes: 4895c771c7f0 ("ipv4: Add FIB nexthop exceptions.") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Keyu Man <kman001@ucr.edu> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: David Ahern <dsahern@kernel.org> Tested-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15tcp: seq_file: Avoid skipping sk during tcp_seek_last_posMartin KaFai Lau1-2/+3
[ Upstream commit 525e2f9fd0229eb10cb460a9e6d978257f24804e ] st->bucket stores the current bucket number. st->offset stores the offset within this bucket that is the sk to be seq_show(). Thus, st->offset only makes sense within the same st->bucket. These two variables are an optimization for the common no-lseek case. When resuming the seq_file iteration (i.e. seq_start()), tcp_seek_last_pos() tries to continue from the st->offset at bucket st->bucket. However, it is possible that the bucket pointed by st->bucket has changed and st->offset may end up skipping the whole st->bucket without finding a sk. In this case, tcp_seek_last_pos() currently continues to satisfy the offset condition in the next (and incorrect) bucket. Instead, regardless of the offset value, the first sk of the next bucket should be returned. Thus, "bucket == st->bucket" check is added to tcp_seek_last_pos(). The chance of hitting this is small and the issue is a decade old, so targeting for the next tree. Fixes: a8b690f98baf ("tcp: Fix slowness in read /proc/net/tcp") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210701200541.1033917-1-kafai@fb.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-12igmp: Add ip_mc_list lock in ip_check_mc_rcuLiu Jian1-0/+2
commit 23d2b94043ca8835bd1e67749020e839f396a1c2 upstream. I got belo