kernel/net/ipv6/ip6_fib.c, branch linux-6.2.y

ipv6: fib6_new_sernum() optimization

2022-11-16T12:42:00Z

Adopt atomic_try_cmpxchg() which is slightly more efficient. Signed-off-by: Eric Dumazet Cc: David Ahern Signed-off-by: David S. Miller

ipv6: annotate accesses to fn->fn_sernum

2022-01-21T04:18:37Z

struct fib6_node's fn_sernum field can be read while other threads change it. Add READ_ONCE()/WRITE_ONCE() annotations. Do not change existing smp barriers in fib6_get_cookie_safe() and __fib6_update_sernum_upto_root() syzbot reported: BUG: KCSAN: data-race in fib6_clean_node / inet6_csk_route_socket write to 0xffff88813df62e2c of 4 bytes by task 1920 on cpu 1: fib6_clean_node+0xc2/0x260 net/ipv6/ip6_fib.c:2178 fib6_walk_continue+0x38e/0x430 net/ipv6/ip6_fib.c:2112 fib6_walk net/ipv6/ip6_fib.c:2160 [inline] fib6_clean_tree net/ipv6/ip6_fib.c:2240 [inline] __fib6_clean_all+0x1a9/0x2e0 net/ipv6/ip6_fib.c:2256 fib6_flush_trees+0x6c/0x80 net/ipv6/ip6_fib.c:2281 rt_genid_bump_ipv6 include/net/net_namespace.h:488 [inline] addrconf_dad_completed+0x57f/0x870 net/ipv6/addrconf.c:4230 addrconf_dad_work+0x908/0x1170 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307 worker_thread+0x616/0xa70 kernel/workqueue.c:2454 kthread+0x1bf/0x1e0 kernel/kthread.c:359 ret_from_fork+0x1f/0x30 read to 0xffff88813df62e2c of 4 bytes by task 15701 on cpu 0: fib6_get_cookie_safe include/net/ip6_fib.h:285 [inline] rt6_get_cookie include/net/ip6_fib.h:306 [inline] ip6_dst_store include/net/ip6_route.h:234 [inline] inet6_csk_route_socket+0x352/0x3c0 net/ipv6/inet6_connection_sock.c:109 inet6_csk_xmit+0x91/0x1e0 net/ipv6/inet6_connection_sock.c:121 __tcp_transmit_skb+0x1323/0x1840 net/ipv4/tcp_output.c:1402 tcp_transmit_skb net/ipv4/tcp_output.c:1420 [inline] tcp_write_xmit+0x1450/0x4460 net/ipv4/tcp_output.c:2680 __tcp_push_pending_frames+0x68/0x1c0 net/ipv4/tcp_output.c:2864 tcp_push+0x2d9/0x2f0 net/ipv4/tcp.c:725 mptcp_push_release net/mptcp/protocol.c:1491 [inline] __mptcp_push_pending+0x46c/0x490 net/mptcp/protocol.c:1578 mptcp_sendmsg+0x9ec/0xa50 net/mptcp/protocol.c:1764 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:643 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] kernel_sendmsg+0x97/0xd0 net/socket.c:745 sock_no_sendpage+0x84/0xb0 net/core/sock.c:3086 inet_sendpage+0x9d/0xc0 net/ipv4/af_inet.c:834 kernel_sendpage+0x187/0x200 net/socket.c:3492 sock_sendpage+0x5a/0x70 net/socket.c:1007 pipe_to_sendpage+0x128/0x160 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x207/0x500 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0x94/0xd0 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:936 splice_direct_to_actor+0x345/0x650 fs/splice.c:891 do_splice_direct+0x106/0x190 fs/splice.c:979 do_sendfile+0x675/0xc40 fs/read_write.c:1245 __do_sys_sendfile64 fs/read_write.c:1310 [inline] __se_sys_sendfile64 fs/read_write.c:1296 [inline] __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000026f -> 0x00000271 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 15701 Comm: syz-executor.2 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 The Fixes tag I chose is probably arbitrary, I do not think we need to backport this patch to older kernels. Fixes: c5cff8561d2d ("ipv6: add rcu grace period before freeing fib6_node") Signed-off-by: Eric Dumazet Reported-by: syzbot Link: https://lore.kernel.org/r/20220120174112.1126644-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski

net: Don't include filter.h from net/sock.h

2021-12-29T16:48:14Z

sock.h is pretty heavily used (5k objects rebuilt on x86 after it's touched). We can drop the include of filter.h from it and add a forward declaration of struct sk_filter instead. This decreases the number of rebuilt objects when bpf.h is touched from ~5k to ~1k. There's a lot of missing includes this was masking. Primarily in networking tho, this time. Signed-off-by: Jakub Kicinski Signed-off-by: Alexei Starovoitov Acked-by: Marc Kleine-Budde Acked-by: Florian Fainelli Acked-by: Nikolay Aleksandrov Acked-by: Stefano Garzarella Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org

ipv6: delay fib6_sernum increase in fib6_add

2021-09-13T12:00:53Z

only increase fib6_sernum in net namespace after add fib6_info successfully. Signed-off-by: zhang kai Reviewed-by: David Ahern Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-08-27T00:57:57Z

drivers/net/wwan/mhi_wwan_mbim.c - drop the extra arg. Signed-off-by: Jakub Kicinski

ipv6: correct comments about fib6_node sernum

2021-08-24T08:59:01Z

correct comments in set and get fn_sernum Signed-off-by: zhang kai Reviewed-by: David Ahern Signed-off-by: David S. Miller

memcg: enable accounting for IP address and routing-related objects

2021-07-20T13:00:38Z

An netadmin inside container can use 'ip a a' and 'ip r a' to assign a large number of ipv4/ipv6 addresses and routing entries and force kernel to allocate megabytes of unaccounted memory for long-lived per-netdevice related kernel objects: 'struct in_ifaddr', 'struct inet6_ifaddr', 'struct fib6_node', 'struct rt6_info', 'struct fib_rules' and ip_fib caches. These objects can be manually removed, though usually they lives in memory till destroy of its net namespace. It makes sense to account for them to restrict the host's memory consumption from inside the memcg-limited container. One of such objects is the 'struct fib6_node' mostly allocated in net/ipv6/route.c::__ip6_ins_rt() inside the lock_bh()/unlock_bh() section: write_lock_bh(&table->tb6_lock); err = fib6_add(&table->tb6_root, rt, info, mxc); write_unlock_bh(&table->tb6_lock); In this case it is not enough to simply add SLAB_ACCOUNT to corresponding kmem cache. The proper memory cgroup still cannot be found due to the incorrect 'in_interrupt()' check used in memcg_kmem_bypass(). Obsoleted in_interrupt() does not describe real execution context properly. >From include/linux/preempt.h: The following macros are deprecated and should not be used in new code: in_interrupt() - We're in NMI,IRQ,SoftIRQ context or have BH disabled To verify the current execution context new macro should be used instead: in_task() - We're in task context Signed-off-by: Vasily Averin Signed-off-by: David S. Miller

ipv6: Add a sysctl to control multipath hash fields

2021-05-18T20:27:32Z

A subsequent patch will add a new multipath hash policy where the packet fields used for multipath hash calculation are determined by user space. This patch adds a sysctl that allows user space to set these fields. The packet fields are represented using a bitmask and are common between IPv4 and IPv6 to allow user space to use the same numbering across both protocols. For example, to hash based on standard 5-tuple: # sysctl -w net.ipv6.fib_multipath_hash_fields=0x0037 net.ipv6.fib_multipath_hash_fields = 0x0037 To avoid introducing holes in 'struct netns_sysctl_ipv6', move the 'bindv6only' field after the multipath hash fields. The kernel rejects unknown fields, for example: # sysctl -w net.ipv6.fib_multipath_hash_fields=0x1000 sysctl: setting key "net.ipv6.fib_multipath_hash_fields": Invalid argument Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller

ipv6: Use a more suitable label name

2021-05-18T20:27:32Z

The 'out_timer' label was added in commit 63152fc0de4d ("[NETNS][IPV6] ip6_fib - gc timer per namespace") when the timer was allocated on the heap. Commit 417f28bb3407 ("netns: dont alloc ipv6 fib timer list") removed the allocation, but kept the label name. Rename it to a more suitable name. Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller

ipv6: fix suspecious RCU usage warning

2021-03-10T20:35:23Z

Syzbot reported the suspecious RCU usage in nexthop_fib6_nh() when called from ipv6_route_seq_show(). The reason is ipv6_route_seq_start() calls rcu_read_lock_bh(), while nexthop_fib6_nh() calls rcu_dereference_rtnl(). The fix proposed is to add a variant of nexthop_fib6_nh() to use rcu_dereference_bh_rtnl() for ipv6_route_seq_show(). The reported trace is as follows: ./include/net/nexthop.h:416 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by syz-executor.0/17895: at: seq_read+0x71/0x12a0 fs/seq_file.c:169 at: seq_file_net include/linux/seq_file_net.h:19 [inline] at: ipv6_route_seq_start+0xaf/0x300 net/ipv6/ip6_fib.c:2616 stack backtrace: CPU: 1 PID: 17895 Comm: syz-executor.0 Not tainted 4.15.0-syzkaller #0 Call Trace: [] __dump_stack lib/dump_stack.c:17 [inline] [] dump_stack+0xd8/0x147 lib/dump_stack.c:53 [] lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5745 [] nexthop_fib6_nh include/net/nexthop.h:416 [inline] [] ipv6_route_native_seq_show net/ipv6/ip6_fib.c:2488 [inline] [] ipv6_route_seq_show+0x436/0x7a0 net/ipv6/ip6_fib.c:2673 [] seq_read+0xccf/0x12a0 fs/seq_file.c:276 [] proc_reg_read+0x10c/0x1d0 fs/proc/inode.c:231 [] do_loop_readv_writev fs/read_write.c:714 [inline] [] do_loop_readv_writev fs/read_write.c:701 [inline] [] do_iter_read+0x49e/0x660 fs/read_write.c:935 [] vfs_readv+0xfb/0x170 fs/read_write.c:997 [] kernel_readv fs/splice.c:361 [inline] [] default_file_splice_read+0x487/0x9c0 fs/splice.c:416 [] do_splice_to+0x129/0x190 fs/splice.c:879 [] splice_direct_to_actor+0x256/0x890 fs/splice.c:951 [] do_splice_direct+0x1dd/0x2b0 fs/splice.c:1060 [] do_sendfile+0x597/0xce0 fs/read_write.c:1459 [] SYSC_sendfile64 fs/read_write.c:1520 [inline] [] SyS_sendfile64+0x155/0x170 fs/read_write.c:1506 [] do_syscall_64+0x1ff/0x310 arch/x86/entry/common.c:305 [] entry_SYSCALL_64_after_hwframe+0x42/0xb7 Fixes: f88d8ea67fbdb ("ipv6: Plumb support for nexthop object in a fib6_info") Reported-by: syzbot Signed-off-by: Wei Wang Cc: David Ahern Cc: Ido Schimmel Cc: Petr Machata Cc: Eric Dumazet Reviewed-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller