kernel.git/net/ipv6/route.c, branch linux-5.17.y

ipv6: make ip6_rt_gc_expire an atomic_t

2022-04-27T12:41:01Z

[ Upstream commit 9cb7c013420f98fa6fd12fc6a5dc055170c108db ] Reads and Writes to ip6_rt_gc_expire always have been racy, as syzbot reported lately [1] There is a possible risk of under-flow, leading to unexpected high value passed to fib6_run_gc(), although I have not observed this in the field. Hosts hitting ip6_dst_gc() very hard are under pretty bad state anyway. [1] BUG: KCSAN: data-race in ip6_dst_gc / ip6_dst_gc read-write to 0xffff888102110744 of 4 bytes by task 13165 on cpu 1: ip6_dst_gc+0x1f3/0x220 net/ipv6/route.c:3311 dst_alloc+0x9b/0x160 net/core/dst.c:86 ip6_dst_alloc net/ipv6/route.c:344 [inline] icmp6_dst_alloc+0xb2/0x360 net/ipv6/route.c:3261 mld_sendpack+0x2b9/0x580 net/ipv6/mcast.c:1807 mld_send_cr net/ipv6/mcast.c:2119 [inline] mld_ifc_work+0x576/0x800 net/ipv6/mcast.c:2651 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289 worker_thread+0x618/0xa70 kernel/workqueue.c:2436 kthread+0x1a9/0x1e0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 read-write to 0xffff888102110744 of 4 bytes by task 11607 on cpu 0: ip6_dst_gc+0x1f3/0x220 net/ipv6/route.c:3311 dst_alloc+0x9b/0x160 net/core/dst.c:86 ip6_dst_alloc net/ipv6/route.c:344 [inline] icmp6_dst_alloc+0xb2/0x360 net/ipv6/route.c:3261 mld_sendpack+0x2b9/0x580 net/ipv6/mcast.c:1807 mld_send_cr net/ipv6/mcast.c:2119 [inline] mld_ifc_work+0x576/0x800 net/ipv6/mcast.c:2651 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289 worker_thread+0x618/0xa70 kernel/workqueue.c:2436 kthread+0x1a9/0x1e0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 value changed: 0x00000bb3 -> 0x00000ba9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 11607 Comm: kworker/0:21 Not tainted 5.18.0-rc1-syzkaller-00037-g42e7a03d3bad-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: mld mld_ifc_work Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: syzbot Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20220413181333.649424-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ipv6: Fix stats accounting in ip6_pkt_drop

2022-04-13T17:27:31Z

[ Upstream commit 1158f79f82d437093aeed87d57df0548bdd68146 ] VRF devices are the loopbacks for VRFs, and a loopback can not be assigned to a VRF. Accordingly, the condition in ip6_pkt_drop should be '||' not '&&'. Fixes: 1d3fd8a10bed ("vrf: Use orig netdev to count Ip6InNoRoutes and a fresh route lookup when sending dest unreach") Reported-by: Pudak, Filip Reported-by: Xiao, Jiguang Signed-off-by: David Ahern Link: https://lore.kernel.org/r/20220404150908.2937-1-dsahern@kernel.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

ipv6: fix data-race in fib6_info_hw_flags_set / fib6_purge_rt

2022-02-17T17:48:24Z

Because fib6_info_hw_flags_set() is called without any synchronization, all accesses to gi6->offload, fi->trap and fi->offload_failed need some basic protection like READ_ONCE()/WRITE_ONCE(). BUG: KCSAN: data-race in fib6_info_hw_flags_set / fib6_purge_rt read to 0xffff8881087d5886 of 1 bytes by task 13953 on cpu 0: fib6_drop_pcpu_from net/ipv6/ip6_fib.c:1007 [inline] fib6_purge_rt+0x4f/0x580 net/ipv6/ip6_fib.c:1033 fib6_del_route net/ipv6/ip6_fib.c:1983 [inline] fib6_del+0x696/0x890 net/ipv6/ip6_fib.c:2028 __ip6_del_rt net/ipv6/route.c:3876 [inline] ip6_del_rt+0x83/0x140 net/ipv6/route.c:3891 __ipv6_dev_ac_dec+0x2b5/0x370 net/ipv6/anycast.c:374 ipv6_dev_ac_dec net/ipv6/anycast.c:387 [inline] __ipv6_sock_ac_close+0x141/0x200 net/ipv6/anycast.c:207 ipv6_sock_ac_close+0x79/0x90 net/ipv6/anycast.c:220 inet6_release+0x32/0x50 net/ipv6/af_inet6.c:476 __sock_release net/socket.c:650 [inline] sock_close+0x6c/0x150 net/socket.c:1318 __fput+0x295/0x520 fs/file_table.c:280 ____fput+0x11/0x20 fs/file_table.c:313 task_work_run+0x8e/0x110 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x160/0x190 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:300 do_syscall_64+0x50/0xd0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae write to 0xffff8881087d5886 of 1 bytes by task 1912 on cpu 1: fib6_info_hw_flags_set+0x155/0x3b0 net/ipv6/route.c:6230 nsim_fib6_rt_hw_flags_set drivers/net/netdevsim/fib.c:668 [inline] nsim_fib6_rt_add drivers/net/netdevsim/fib.c:691 [inline] nsim_fib6_rt_insert drivers/net/netdevsim/fib.c:756 [inline] nsim_fib6_event drivers/net/netdevsim/fib.c:853 [inline] nsim_fib_event drivers/net/netdevsim/fib.c:886 [inline] nsim_fib_event_work+0x284f/0x2cf0 drivers/net/netdevsim/fib.c:1477 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307 worker_thread+0x616/0xa70 kernel/workqueue.c:2454 kthread+0x2c7/0x2e0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 value changed: 0x22 -> 0x2a Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 1912 Comm: kworker/1:3 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events nsim_fib_event_work Fixes: 0c5fcf9e249e ("IPv6: Add "offload failed" indication to routes") Fixes: bb3c4ab93e44 ("ipv6: Add "offload" and "trap" indications to routes") Signed-off-by: Eric Dumazet Cc: Amit Cohen Cc: Ido Schimmel Reported-by: syzbot Link: https://lore.kernel.org/r/20220216173217.3792411-2-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski

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

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

2022-01-05T22:36:10Z

No conflicts. Signed-off-by: Jakub Kicinski

ipv6: Do cleanup if attribute validation fails in multipath route

2022-01-03T18:04:42Z

As Nicolas noted, if gateway validation fails walking the multipath attribute the code should jump to the cleanup to free previously allocated memory. Fixes: 1ff15a710a86 ("ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route") Signed-off-by: David Ahern Acked-by: Nicolas Dichtel Link: https://lore.kernel.org/r/20220103170555.94638-1-dsahern@kernel.org Signed-off-by: Jakub Kicinski

ipv6: Continue processing multipath route even if gateway attribute is invalid

2022-01-03T18:02:00Z

ip6_route_multipath_del loop continues processing the multipath attribute even if delete of a nexthop path fails. For consistency, do the same if the gateway attribute is invalid. Fixes: 1ff15a710a86 ("ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route") Signed-off-by: David Ahern Acked-by: Nicolas Dichtel Link: https://lore.kernel.org/r/20220103171911.94739-1-dsahern@kernel.org Signed-off-by: Jakub Kicinski

lwtunnel: Validate RTA_ENCAP_TYPE attribute length

2021-12-31T14:31:59Z

lwtunnel_valid_encap_type_attr is used to validate encap attributes within a multipath route. Add length validation checking to the type. lwtunnel_valid_encap_type_attr is called converting attributes to fib{6,}_config struct which means it is used before fib_get_nhs, ip6_route_multipath_add, and ip6_route_multipath_del - other locations that use rtnh_ok and then nla_get_u16 on RTA_ENCAP_TYPE attribute. Fixes: 9ed59592e3e3 ("lwtunnel: fix autoload of lwt modules") Signed-off-by: David Ahern Signed-off-by: David S. Miller

ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route

2021-12-31T14:31:59Z

Make sure RTA_GATEWAY for IPv6 multipath route has enough bytes to hold an IPv6 address. Fixes: 6b9ea5a64ed5 ("ipv6: fix multipath route replace error recovery") Signed-off-by: David Ahern Cc: Roopa Prabhu Signed-off-by: David S. Miller

ipv6: Check attribute length for RTA_GATEWAY in multipath route

2021-12-31T14:31:59Z

Commit referenced in the Fixes tag used nla_memcpy for RTA_GATEWAY as does the current nla_get_in6_addr. nla_memcpy protects against accessing memory greater than what is in the attribute, but there is no check requiring the attribute to have an IPv6 address. Add it. Fixes: 51ebd3181572 ("ipv6: add support of equal cost multipath (ECMP)") Signed-off-by: David Ahern Cc: Nicolas Dichtel Signed-off-by: David S. Miller