kernel/include/net/nexthop.h, branch linux-5.11.y

ipv6: fix suspecious RCU usage warning

2021-03-30T12:30:18Z

[ Upstream commit 28259bac7f1dde06d8ba324e222bbec9d4e92f2b ] 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 Signed-off-by: Sasha Levin

nexthop: Pass extack to register_nexthop_notifier()

2020-11-06T19:28:49Z

This will be used by the next patch which extends the function to replay all the existing nexthops to the notifier block being registered. Device drivers will be able to pass extack to the function since it is passed to them upon reload from devlink. Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: Jakub Kicinski

nexthop: Emit a notification when a nexthop is added

2020-11-06T19:28:49Z

Emit a notification in the nexthop notification chain when a new nexthop is added (not replaced). The nexthop can either be a new group or a single nexthop. The notification is sent after the nexthop is inserted into the red-black tree, as listeners might need to callback into the nexthop code with the nexthop ID in order to mark the nexthop as offloaded. A 'REPLACE' notification is emitted instead of 'ADD' as the distinction between the two is not important for in-kernel listeners. In case the listener is not familiar with the encoded nexthop ID, it can simply treat it as a new one. This is also consistent with the route offload API. Changes since RFC: * Reword commit message Signed-off-by: Ido Schimmel Signed-off-by: Jakub Kicinski

nexthop: Allow setting "offload" and "trap" indications on nexthops

2020-11-06T19:28:49Z

Add a function that can be called by device drivers to set "offload" or "trap" indication on nexthops following nexthop notifications. Changes since RFC: * s/nexthop_hw_flags_set/nexthop_set_hw_flags/ Signed-off-by: Ido Schimmel Signed-off-by: Jakub Kicinski

nexthop: Add nexthop notification data structures

2020-11-06T19:28:48Z

Add data structures that will be used for nexthop replace and delete notifications in the previously introduced nexthop notification chain. New data structures are added instead of passing the existing nexthop code structures directly for several reasons. First, the existing structures encode a lot of bookkeeping information which is irrelevant for listeners of the notification chain. Second, the existing structures can be changed without worrying about introducing regressions in listeners since they are not accessed directly by them. Third, listeners of the notification chain do not need to each parse the relatively complex nexthop code structures. They are passing the required information in a simplified way. Note that a single 'has_encap' bit is added instead of the actual encapsulation information since current listeners do not support such nexthops. Changes since RFC: * s/is_encap/has_encap/ Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: Jakub Kicinski

nexthop: Remove NEXTHOP_EVENT_ADD

2020-09-15T23:31:11Z

Not used anywhere. Signed-off-by: Ido Schimmel Suggested-by: David Ahern Signed-off-by: David S. Miller

nexthop: Remove unused function declaration from header file

2020-09-15T23:31:03Z

Not used or implemented anywhere. Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller

vxlan: Remove access to nexthop group struct

2020-06-10T20:20:20Z

vxlan driver should be using helpers to access nexthop struct internals. Remove open check if whether nexthop is multipath in favor of the existing nexthop_is_multipath helper. Add a new helper, nexthop_has_v4, to cover the need to check has_v4 in a group. Fixes: 1274e1cc4226 ("vxlan: ecmp support for mac fdb entries") Cc: Roopa Prabhu Signed-off-by: David Ahern Signed-off-by: David S. Miller

nexthop: Fix fdb labeling for groups

2020-06-10T20:18:40Z

fdb nexthops are marked with a flag. For standalone nexthops, a flag was added to the nh_info struct. For groups that flag was added to struct nexthop when it should have been added to the group information. Fix by removing the flag from the nexthop struct and adding a flag to nh_group that mirrors nh_info and is really only a caching of the individual types. Add a helper, nexthop_is_fdb, for use by the vxlan code and fixup the internal code to use the flag from either nh_info or nh_group. v2 - propagate fdb_nh in remove_nh_grp_entry Fixes: 38428d68719c ("nexthop: support for fdb ecmp nexthops") Cc: Roopa Prabhu Signed-off-by: David Ahern Signed-off-by: David S. Miller

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

2020-06-01T00:48:46Z

xdp_umem.c had overlapping changes between the 64-bit math fix for the calculation of npgs and the removal of the zerocopy memory type which got rid of the chunk_size_nohdr member. The mlx5 Kconfig conflict is a case where we just take the net-next copy of the Kconfig entry dependency as it takes on the ESWITCH dependency by one level of indirection which is what the 'net' conflicting change is trying to ensure. Signed-off-by: David S. Miller