The cited commit refactored the flow action initialization sequence to
use an interface method when translating tc action instances to flow
offload objects. The refactored version skips the initialization of the
generic flow action attributes for tc actions, such as pedit, that allocate
more than one offload entry. This can cause potential issues for drivers
mapping flow action ids.

Populate the generic flow action fields for all the flow action entries.

Fixes: c54e1d92 ("flow_offload: add ops to tc_action_ops for flow action setup")
Signed-off-by: NOz Shlomo <ozsh@nvidia.com>
Reviewed-by: NRoi Dayan <roid@nvidia.com>

----
v1 -> v2:
 - coalese the generic flow action fields initialization to a single loop
Reviewed-by: NBaowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, when inserting a new filter that needs to sit at the head
of chain 0, it will first update the heads pointer on all devices using
the (shared) block, and only then complete the initialization of the new
element so that it has a "next" element.

This can lead to a situation that the chain 0 head is propagated to
another CPU before the "next" initialization is done. When this race
condition is triggered, packets being matched on that CPU will simply
miss all other filters, and will flow through the stack as if there were
no other filters installed. If the system is using OVS + TC, such
packets will get handled by vswitchd via upcall, which results in much
higher latency and reordering. For other applications it may result in
packet drops.

This is reproducible with a tc only setup, but it varies from system to
system. It could be reproduced with a shared block amongst 10 veth
tunnels, and an ingress filter mirroring packets to another veth.
That's because using the last added veth tunnel to the shared block to
do the actual traffic, it makes the race window bigger and easier to
trigger.

The fix is rather simple, to just initialize the next pointer of the new
filter instance (tp) before propagating the head change.

The fixes tag is pointing to the original code though this issue should
only be observed when using it unlocked.

Fixes: 2190d1d0 ("net: sched: introduce helpers to work with filter chains")
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Reviewed-by: NDavide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/b97d5f4eaffeeb9d058155bcab63347527261abf.1649341369.git.marcelo.leitner@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

For better error reporting to user space, add an extack message when the
requested action does not support offload.

Example:

 # echo 1 > /sys/kernel/tracing/events/netlink/netlink_extack/enable

 # tc filter add dev dummy0 ingress pref 1 proto all matchall skip_sw action nat ingress 192.0.2.1 198.51.100.1
 Error: cls_matchall: Failed to setup flow action.
 We have an error talking to the kernel

 # cat /sys/kernel/tracing/trace_pipe
       tc-181     [000] b..1.    88.406093: netlink_extack: msg=Action does not support offload
       tc-181     [000] .....    88.406108: netlink_extack: msg=cls_matchall: Failed to setup flow action
Signed-off-by: NIdo Schimmel <idosch@nvidia.com>
Reviewed-by: NPetr Machata <petrm@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The callback is used by various actions to populate the flow action
structure prior to offload. Pass extack to this callback so that the
various actions will be able to report accurate error messages to user
space.
Signed-off-by: NIdo Schimmel <idosch@nvidia.com>
Reviewed-by: NPetr Machata <petrm@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

syzbot found a data-race [1] which lead me to add __rcu
annotations to netdev->qdisc, and proper accessors
to get LOCKDEP support.

[1]
BUG: KCSAN: data-race in dev_activate / qdisc_lookup_rcu

write to 0xffff888168ad6410 of 8 bytes by task 13559 on cpu 1:
 attach_default_qdiscs net/sched/sch_generic.c:1167 [inline]
 dev_activate+0x2ed/0x8f0 net/sched/sch_generic.c:1221
 __dev_open+0x2e9/0x3a0 net/core/dev.c:1416
 __dev_change_flags+0x167/0x3f0 net/core/dev.c:8139
 rtnl_configure_link+0xc2/0x150 net/core/rtnetlink.c:3150
 __rtnl_newlink net/core/rtnetlink.c:3489 [inline]
 rtnl_newlink+0xf4d/0x13e0 net/core/rtnetlink.c:3529
 rtnetlink_rcv_msg+0x745/0x7e0 net/core/rtnetlink.c:5594
 netlink_rcv_skb+0x14e/0x250 net/netlink/af_netlink.c:2494
 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5612
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x602/0x6d0 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x728/0x850 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2413
 ___sys_sendmsg net/socket.c:2467 [inline]
 __sys_sendmsg+0x195/0x230 net/socket.c:2496
 __do_sys_sendmsg net/socket.c:2505 [inline]
 __se_sys_sendmsg net/socket.c:2503 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2503
 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

read to 0xffff888168ad6410 of 8 bytes by task 13560 on cpu 0:
 qdisc_lookup_rcu+0x30/0x2e0 net/sched/sch_api.c:323
 __tcf_qdisc_find+0x74/0x3a0 net/sched/cls_api.c:1050
 tc_del_tfilter+0x1c7/0x1350 net/sched/cls_api.c:2211
 rtnetlink_rcv_msg+0x5ba/0x7e0 net/core/rtnetlink.c:5585
 netlink_rcv_skb+0x14e/0x250 net/netlink/af_netlink.c:2494
 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5612
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x602/0x6d0 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x728/0x850 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2413
 ___sys_sendmsg net/socket.c:2467 [inline]
 __sys_sendmsg+0x195/0x230 net/socket.c:2496
 __do_sys_sendmsg net/socket.c:2505 [inline]
 __se_sys_sendmsg net/socket.c:2503 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2503
 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: 0xffffffff85dee080 -> 0xffff88815d96ec00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13560 Comm: syz-executor.2 Not tainted 5.17.0-rc3-syzkaller-00116-gf1baf68e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 470502de ("net: sched: unlock rules update API")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently tc skb extension is used to send miss info from
tc to ovs datapath module, and driver to tc. For the tc to ovs
miss it is currently always allocated even if it will not
be used by ovs datapath (as it depends on a requested feature).

Export the static key which is used by openvswitch module to
guard this code path as well, so it will be skipped if ovs
datapath doesn't need it. Enable this code path once
ovs datapath needs it.
Signed-off-by: NPaul Blakey <paulb@nvidia.com>
Reviewed-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Whenever tc_new_tfilter() jumps back to replay: label,
we need to make sure @q and @chain local variables are cleared again,
or risk use-after-free as in [1]

For consistency, apply the same fix in tc_ctl_chain()

BUG: KASAN: use-after-free in mini_qdisc_pair_swap+0x1b9/0x1f0 net/sched/sch_generic.c:1581
Write of size 8 at addr ffff8880985c4b08 by task syz-executor.4/1945

CPU: 0 PID: 1945 Comm: syz-executor.4 Not tainted 5.17.0-rc1-syzkaller-00495-gff58831f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0x8d/0x336 mm/kasan/report.c:255
 __kasan_report mm/kasan/report.c:442 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
 mini_qdisc_pair_swap+0x1b9/0x1f0 net/sched/sch_generic.c:1581
 tcf_chain_head_change_item net/sched/cls_api.c:372 [inline]
 tcf_chain0_head_change.isra.0+0xb9/0x120 net/sched/cls_api.c:386
 tcf_chain_tp_insert net/sched/cls_api.c:1657 [inline]
 tcf_chain_tp_insert_unique net/sched/cls_api.c:1707 [inline]
 tc_new_tfilter+0x1e67/0x2350 net/sched/cls_api.c:2086
 rtnetlink_rcv_msg+0x80d/0xb80 net/core/rtnetlink.c:5583
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 ____sys_sendmsg+0x331/0x810 net/socket.c:2413
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
 __sys_sendmmsg+0x195/0x470 net/socket.c:2553
 __do_sys_sendmmsg net/socket.c:2582 [inline]
 __se_sys_sendmmsg net/socket.c:2579 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2579
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f2647172059
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2645aa5168 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f2647285100 RCX: 00007f2647172059
RDX: 040000000000009f RSI: 00000000200002c0 RDI: 0000000000000006
RBP: 00007f26471cc08d R08: 0000000000000000 R09: 0000000000000000
R10: 9e00000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffb3f7f02f R14: 00007f2645aa5300 R15: 0000000000022000
 </TASK>

Allocated by task 1944:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:436 [inline]
 ____kasan_kmalloc mm/kasan/common.c:515 [inline]
 ____kasan_kmalloc mm/kasan/common.c:474 [inline]
 __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524
 kmalloc_node include/linux/slab.h:604 [inline]
 kzalloc_node include/linux/slab.h:726 [inline]
 qdisc_alloc+0xac/0xa10 net/sched/sch_generic.c:941
 qdisc_create.constprop.0+0xce/0x10f0 net/sched/sch_api.c:1211
 tc_modify_qdisc+0x4c5/0x1980 net/sched/sch_api.c:1660
 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5592
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 ____sys_sendmsg+0x331/0x810 net/socket.c:2413
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
 __sys_sendmmsg+0x195/0x470 net/socket.c:2553
 __do_sys_sendmmsg net/socket.c:2582 [inline]
 __se_sys_sendmmsg net/socket.c:2579 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2579
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 3609:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:45
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free+0x130/0x160 mm/kasan/common.c:328
 kasan_slab_free include/linux/kasan.h:236 [inline]
 slab_free_hook mm/slub.c:1728 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754
 slab_free mm/slub.c:3509 [inline]
 kfree+0xcb/0x280 mm/slub.c:4562
 rcu_do_batch kernel/rcu/tree.c:2527 [inline]
 rcu_core+0x7b8/0x1540 kernel/rcu/tree.c:2778
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558

Last potentially related work creation:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348
 __call_rcu kernel/rcu/tree.c:3026 [inline]
 call_rcu+0xb1/0x740 kernel/rcu/tree.c:3106
 qdisc_put_unlocked+0x6f/0x90 net/sched/sch_generic.c:1109
 tcf_block_release+0x86/0x90 net/sched/cls_api.c:1238
 tc_new_tfilter+0xc0d/0x2350 net/sched/cls_api.c:2148
 rtnetlink_rcv_msg+0x80d/0xb80 net/core/rtnetlink.c:5583
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 ____sys_sendmsg+0x331/0x810 net/socket.c:2413
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
 __sys_sendmmsg+0x195/0x470 net/socket.c:2553
 __do_sys_sendmmsg net/socket.c:2582 [inline]
 __se_sys_sendmmsg net/socket.c:2579 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2579
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff8880985c4800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 776 bytes inside of
 1024-byte region [ffff8880985c4800, ffff8880985c4c00)
The buggy address belongs to the page:
page:ffffea0002617000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x985c0
head:ffffea0002617000 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888010c41dc0
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 1941, ts 1038999441284, free_ts 1033444432829
 prep_new_page mm/page_alloc.c:2434 [inline]
 get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389
 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2271
 alloc_slab_page mm/slub.c:1799 [inline]
 allocate_slab mm/slub.c:1944 [inline]
 new_slab+0x28a/0x3b0 mm/slub.c:2004
 ___slab_alloc+0x87c/0xe90 mm/slub.c:3018
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3105
 slab_alloc_node mm/slub.c:3196 [inline]
 slab_alloc mm/slub.c:3238 [inline]
 __kmalloc+0x2fb/0x340 mm/slub.c:4420
 kmalloc include/linux/slab.h:586 [inline]
 kzalloc include/linux/slab.h:715 [inline]
 __register_sysctl_table+0x112/0x1090 fs/proc/proc_sysctl.c:1335
 neigh_sysctl_register+0x2c8/0x5e0 net/core/neighbour.c:3787
 devinet_sysctl_register+0xb1/0x230 net/ipv4/devinet.c:2618
 inetdev_init+0x286/0x580 net/ipv4/devinet.c:278
 inetdev_event+0xa8a/0x15d0 net/ipv4/devinet.c:1532
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:84
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1919
 call_netdevice_notifiers_extack net/core/dev.c:1931 [inline]
 call_netdevice_notifiers net/core/dev.c:1945 [inline]
 register_netdevice+0x1073/0x1500 net/core/dev.c:9698
 veth_newlink+0x59c/0xa90 drivers/net/veth.c:1722
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1352 [inline]
 free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1404
 free_unref_page_prepare mm/page_alloc.c:3325 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3404
 release_pages+0x748/0x1220 mm/swap.c:956
 tlb_batch_pages_flush mm/mmu_gather.c:50 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:243 [inline]
 tlb_flush_mmu+0xe9/0x6b0 mm/mmu_gather.c:250
 zap_pte_range mm/memory.c:1441 [inline]
 zap_pmd_range mm/memory.c:1490 [inline]
 zap_pud_range mm/memory.c:1519 [inline]
 zap_p4d_range mm/memory.c:1540 [inline]
 unmap_page_range+0x1d1d/0x2a30 mm/memory.c:1561
 unmap_single_vma+0x198/0x310 mm/memory.c:1606
 unmap_vmas+0x16b/0x2f0 mm/memory.c:1638
 exit_mmap+0x201/0x670 mm/mmap.c:3178
 __mmput+0x122/0x4b0 kernel/fork.c:1114
 mmput+0x56/0x60 kernel/fork.c:1135
 exit_mm kernel/exit.c:507 [inline]
 do_exit+0xa3c/0x2a30 kernel/exit.c:793
 do_group_exit+0xd2/0x2f0 kernel/exit.c:935
 __do_sys_exit_group kernel/exit.c:946 [inline]
 __se_sys_exit_group kernel/exit.c:944 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:944
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Memory state around the buggy address:
 ffff8880985c4a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880985c4a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880985c4b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff8880985c4b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880985c4c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: 470502de ("net: sched: unlock rules update API")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20220131172018.3704490-1-eric.dumazet@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Netfilter conntrack maintains NAT flags per connection indicating
whether NAT was configured for the connection. Openvswitch maintains
NAT flags on the per packet flow key ct_state field, indicating
whether NAT was actually executed on the packet.

When a packet misses from tc to ovs the conntrack NAT flags are set.
However, NAT was not necessarily executed on the packet because the
connection's state might still be in NEW state. As such, openvswitch
wrongly assumes that NAT was executed and sets an incorrect flow key
NAT flags.

Fix this, by flagging to openvswitch which NAT was actually done in
act_ct via tc_skb_ext and tc_skb_cb to the openvswitch module, so
the packet flow key NAT flags will be correctly set.

Fixes: b57dc7c1 ("net/sched: Introduce action ct")
Signed-off-by: NPaul Blakey <paulb@nvidia.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20220106153804.26451-1-paulb@nvidia.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Fix following coccicheck warnings:
./net/sched/cls_api.c:3333:17-18: WARNING opportunity for min()
./net/sched/cls_api.c:3389:17-18: WARNING opportunity for min()
./net/sched/cls_api.c:3427:17-18: WARNING opportunity for min()
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NYang Li <yang.lee@linux.alibaba.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add process to validate flags of filter and actions when adding
a tc filter.

We need to prevent adding filter with flags conflicts with its actions.
Signed-off-by: NBaowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: NLouis Peens <louis.peens@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use flow_indr_dev_register/flow_indr_dev_setup_offload to
offload tc action.

We need to call tc_cleanup_flow_action to clean up tc action entry since
in tc_setup_action, some actions may hold dev refcnt, especially the mirror
action.
Signed-off-by: NBaowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: NLouis Peens <louis.peens@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a new ops to tc_action_ops for flow action setup.

Refactor function tc_setup_flow_action to use this new ops.

We make this change to facilitate to add standalone action module.

We will also use this ops to offload action independent of filter
in following patch.
Signed-off-by: NBaowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To improves readability, we rename offload functions with offload instead
of flow.

The term flow is related to exact matches, so we rename these functions
with offload.

We make this change to facilitate single action offload functions naming.
Signed-off-by: NBaowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add index to flow_action_entry structure and delete index from police and
gate child structure.

We make this change to offload tc action for driver to identify a tc
action.
Signed-off-by: NBaowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Zone id is not restored if we passed ct and ct rejected the connection,
as there is no ct info on the skb.

Save the zone from tc skb cb to tc skb extension and pass it on to
ovs, use that info to restore the zone id for invalid connections.

Fixes: d29334c1 ("net/sched: act_api: fix miss set post_ct for ovs after do conntrack in act_ct")
Signed-off-by: NPaul Blakey <paulb@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

BPF layer extends the qdisc control block via struct bpf_skb_data_end
and because of that there is no more room to add variables to the
qdisc layer control block without going over the skb->cb size.

Extend the qdisc control block with a tc control block,
and move all tc related variables to there as a pre-step for
extending the tc control block with additional members.
Signed-off-by: NPaul Blakey <paulb@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

We need to return EOPNOTSUPP for the unsupported mpls action type when
setup the flow action.

In the original implement, we will return 0 for the unsupported mpls
action type, actually we do not setup it and the following actions
to the flow action entry.

Fixes: 9838b20a ("net: sched: take rtnl lock in tc_setup_flow_action()")
Signed-off-by: NBaowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, when creating an ingress qdisc on an indirect device before
the driver registered for callbacks, the driver will not have a chance
to register its filter configuration callbacks.

To fix that, modify the code such that it keeps track of all the ingress
qdiscs that call flow_indr_dev_setup_offload(). When a driver calls
flow_indr_dev_register(),  go through the list of tracked ingress qdiscs
and call the driver callback entry point so as to give it a chance to
register its callback.
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NEli Cohen <elic@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tc_new_tfilter() can replay a request if it got EAGAIN. The cited commit
didn't account for this when it converted TC action ->init() API
to use flags instead of parameters. This can lead to passing stale flags
down the call chain which results in trying to lock rtnl when it's
already locked, deadlocking the entire system.

Fix by making sure to reset flags on each replay.

============================================
WARNING: possible recursive locking detected
5.14.0-rc3-custom-49011-g3d2bbb4f104d #447 Not tainted
--------------------------------------------
tc/37605 is trying to acquire lock:
ffffffff841df2f0 (rtnl_mutex){+.+.}-{3:3}, at: tc_setup_cb_add+0x14b/0x4d0

but task is already holding lock:
ffffffff841df2f0 (rtnl_mutex){+.+.}-{3:3}, at: tc_new_tfilter+0xb12/0x22e0

other info that might help us debug this:
 Possible unsafe locking scenario:
       CPU0
       ----
  lock(rtnl_mutex);
  lock(rtnl_mutex);

 *** DEADLOCK ***
 May be due to missing lock nesting notation
1 lock held by tc/37605:
 #0: ffffffff841df2f0 (rtnl_mutex){+.+.}-{3:3}, at: tc_new_tfilter+0xb12/0x22e0

stack backtrace:
CPU: 0 PID: 37605 Comm: tc Not tainted 5.14.0-rc3-custom-49011-g3d2bbb4f104d #447
Hardware name: Mellanox Technologies Ltd. MSN2010/SA002610, BIOS 5.6.5 08/24/2017
Call Trace:
 dump_stack_lvl+0x8b/0xb3
 __lock_acquire.cold+0x175/0x3cb
 lock_acquire+0x1a4/0x4f0
 __mutex_lock+0x136/0x10d0
 fl_hw_replace_filter+0x458/0x630 [cls_flower]
 fl_change+0x25f2/0x4a64 [cls_flower]
 tc_new_tfilter+0xa65/0x22e0
 rtnetlink_rcv_msg+0x86c/0xc60
 netlink_rcv_skb+0x14d/0x430
 netlink_unicast+0x539/0x7e0
 netlink_sendmsg+0x84d/0xd80
 ____sys_sendmsg+0x7ff/0x970
 ___sys_sendmsg+0xf8/0x170
 __sys_sendmsg+0xea/0x1b0
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f7b93b6c0a7
Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 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>
RSP: 002b:00007ffe365b3818 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7b93b6c0a7
RDX: 0000000000000000 RSI: 00007ffe365b3880 RDI: 0000000000000003
RBP: 00000000610a75f6 R08: 0000000000000001 R09: 0000000000000000
R10: fffffffffffff3a9 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007ffe365b7b58 R15: 00000000004822c0

Fixes: 695176bf ("net_sched: refactor TC action init API")
Signed-off-by: NMark Bloch <mbloch@nvidia.com>
Reviewed-by: NVlad Buslov <vladbu@nvidia.com>
Reviewed-by: NIdo Schimmel <idosch@nvidia.com>
Tested-by: NIdo Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20210810034305.63997-1-mbloch@nvidia.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

TC action ->init() API has 10 parameters, it becomes harder
to read. Some of them are just boolean and can be replaced
by flags. Similarly for the internal API tcf_action_init()
and tcf_exts_validate().

This patch converts them to flags and fold them into
the upper 16 bits of "flags", whose lower 16 bits are still
reserved for user-space. More specifically, the following
kernel flags are introduced:

TCA_ACT_FLAGS_POLICE replace 'name' in a few contexts, to
distinguish whether it is compatible with policer.

TCA_ACT_FLAGS_BIND replaces 'bind', to indicate whether
this action is bound to a filter.

TCA_ACT_FLAGS_REPLACE  replaces 'ovr' in most contexts,
means we are replacing an existing action.

TCA_ACT_FLAGS_NO_RTNL replaces 'rtnl_held' but has the
opposite meaning, because we still hold RTNL in most
cases.

The only user-space flag TCA_ACT_FLAGS_NO_PERCPU_STATS is
untouched and still stored as before.

I have tested this patch with tdc and I do not see any
failure related to this patch.
Tested-by: NVlad Buslov <vladbu@nvidia.com>
Acked-by: Jamal Hadi Salim<jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <cong.wang@bytedance.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

currently, only 'ingress' and 'clsact ingress' qdiscs store the tc 'chain
id' in the skb extension. However, userspace programs (like ovs) are able
to setup egress rules, and datapath gets confused in case it doesn't find
the 'chain id' for a packet that's "recirculated" by tc.
Change tcf_classify() to have the same semantic as tcf_classify_ingress()
so that a single function can be called in ingress / egress, using the tc
ingress / egress block respectively.
Suggested-by: NAlaa Hleilel <alaa@nvidia.com>
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Reviewed-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The 4th parameter in tc_chain_notify() should be flags rather than seq.
Let's change it back correctly.

Fixes: 32a4f5ec ("net: sched: introduce chain object to uapi")
Signed-off-by: NYajun Deng <yajun.deng@linux.dev>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It has been deal with the 'if (err' statement in rtnetlink_send()
and rtnl_unicast(). so remove unnecessary if statement.

v2: use the raw name rtnetlink_send().
Signed-off-by: NYajun Deng <yajun.deng@linux.dev>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Function skb_ext_add() doesn't initialize created skb extension with any
value and leaves it up to the user. However, since extension of type
TC_SKB_EXT originally contained only single value tc_skb_ext->chain its
users used to just assign the chain value without setting whole extension
memory to zero first. This assumption changed when TC_SKB_EXT extension was
extended with additional fields but not all users were updated to
initialize the new fields which leads to use of uninitialized memory
afterwards. UBSAN log:

[  778.299821] UBSAN: invalid-load in net/openvswitch/flow.c:899:28
[  778.301495] load of value 107 is not a valid value for type '_Bool'
[  778.303215] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc7+ #2
[  778.304933] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[  778.307901] Call Trace:
[  778.308680]  <IRQ>
[  778.309358]  dump_stack+0xbb/0x107
[  778.310307]  ubsan_epilogue+0x5/0x40
[  778.311167]  __ubsan_handle_load_invalid_value.cold+0x43/0x48
[  778.312454]  ? memset+0x20/0x40
[  778.313230]  ovs_flow_key_extract.cold+0xf/0x14 [openvswitch]
[  778.314532]  ovs_vport_receive+0x19e/0x2e0 [openvswitch]
[  778.315749]  ? ovs_vport_find_upcall_portid+0x330/0x330 [openvswitch]
[  778.317188]  ? create_prof_cpu_mask+0x20/0x20
[  778.318220]  ? arch_stack_walk+0x82/0xf0
[  778.319153]  ? secondary_startup_64_no_verify+0xb0/0xbb
[  778.320399]  ? stack_trace_save+0x91/0xc0
[  778.321362]  ? stack_trace_consume_entry+0x160/0x160
[  778.322517]  ? lock_release+0x52e/0x760
[  778.323444]  netdev_frame_hook+0x323/0x610 [openvswitch]
[  778.324668]  ? ovs_netdev_get_vport+0xe0/0xe0 [openvswitch]
[  778.325950]  __netif_receive_skb_core+0x771/0x2db0
[  778.327067]  ? lock_downgrade+0x6e0/0x6f0
[  778.328021]  ? lock_acquire+0x565/0x720
[  778.328940]  ? generic_xdp_tx+0x4f0/0x4f0
[  778.329902]  ? inet_gro_receive+0x2a7/0x10a0
[  778.330914]  ? lock_downgrade+0x6f0/0x6f0
[  778.331867]  ? udp4_gro_receive+0x4c4/0x13e0
[  778.332876]  ? lock_release+0x52e/0x760
[  778.333808]  ? dev_gro_receive+0xcc8/0x2380
[  778.334810]  ? lock_downgrade+0x6f0/0x6f0
[  778.335769]  __netif_receive_skb_list_core+0x295/0x820
[  778.336955]  ? process_backlog+0x780/0x780
[  778.337941]  ? mlx5e_rep_tc_netdevice_event_unregister+0x20/0x20 [mlx5_core]
[  778.339613]  ? seqcount_lockdep_reader_access.constprop.0+0xa7/0xc0
[  778.341033]  ? kvm_clock_get_cycles+0x14/0x20
[  778.342072]  netif_receive_skb_list_internal+0x5f5/0xcb0
[  778.343288]  ? __kasan_kmalloc+0x7a/0x90
[  778.344234]  ? mlx5e_handle_rx_cqe_mpwrq+0x9e0/0x9e0 [mlx5_core]
[  778.345676]  ? mlx5e_xmit_xdp_frame_mpwqe+0x14d0/0x14d0 [mlx5_core]
[  778.347140]  ? __netif_receive_skb_list_core+0x820/0x820
[  778.348351]  ? mlx5e_post_rx_mpwqes+0xa6/0x25d0 [mlx5_core]
[  778.349688]  ? napi_gro_flush+0x26c/0x3c0
[  778.350641]  napi_complete_done+0x188/0x6b0
[  778.351627]  mlx5e_napi_poll+0x373/0x1b80 [mlx5_core]
[  778.352853]  __napi_poll+0x9f/0x510
[  778.353704]  ? mlx5_flow_namespace_set_mode+0x260/0x260 [mlx5_core]
[  778.355158]  net_rx_action+0x34c/0xa40
[  778.356060]  ? napi_threaded_poll+0x3d0/0x3d0
[  778.357083]  ? sched_clock_cpu+0x18/0x190
[  778.358041]  ? __common_interrupt+0x8e/0x1a0
[  778.359045]  __do_softirq+0x1ce/0x984
[  778.359938]  __irq_exit_rcu+0x137/0x1d0
[  778.360865]  irq_exit_rcu+0xa/0x20
[  778.361708]  common_interrupt+0x80/0xa0
[  778.362640]  </IRQ>
[  778.363212]  asm_common_interrupt+0x1e/0x40
[  778.364204] RIP: 0010:native_safe_halt+0xe/0x10
[  778.365273] Code: 4f ff ff ff 4c 89 e7 e8 50 3f 40 fe e9 dc fe ff ff 48 89 df e8 43 3f 40 fe eb 90 cc e9 07 00 00 00 0f 00 2d 74 05 62 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d 64 05 62 00 f4 c3 cc cc 0f 1f 44 00
[  778.369355] RSP: 0018:ffffffff84407e48 EFLAGS: 00000246
[  778.370570] RAX: ffff88842de46a80 RBX: ffffffff84425840 RCX: ffffffff83418468
[  778.372143] RDX: 000000000026f1da RSI: 0000000000000004 RDI: ffffffff8343af5e
[  778.373722] RBP: fffffbfff0884b08 R08: 0000000000000000 R09: ffff88842de46bcb
[  778.375292] R10: ffffed1085bc8d79 R11: 0000000000000001 R12: 0000000000000000
[  778.376860] R13: ffffffff851124a0 R14: 0000000000000000 R15: dffffc0000000000
[  778.378491]  ? rcu_eqs_enter.constprop.0+0xb8/0xe0
[  778.379606]  ? default_idle_call+0x5e/0xe0
[  778.380578]  default_idle+0xa/0x10
[  778.381406]  default_idle_call+0x96/0xe0
[  778.382350]  do_idle+0x3d4/0x550
[  778.383153]  ? arch_cpu_idle_exit+0x40/0x40
[  778.384143]  cpu_startup_entry+0x19/0x20
[  778.385078]  start_kernel+0x3c7/0x3e5
[  778.385978]  secondary_startup_64_no_verify+0xb0/0xbb

Fix the issue by providing new function tc_skb_ext_alloc() that allocates
tc skb extension and initializes its memory to 0 before returning it to the
caller. Change all existing users to use new API instead of calling
skb_ext_add() directly.

Fixes: 038ebb1a ("net/sched: act_ct: fix miss set mru for ovs after defrag in act_ct")
Fixes: d29334c1 ("net/sched: act_api: fix miss set post_ct for ovs after do conntrack in act_ct")
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Acked-by: NCong Wang <cong.wang@bytedance.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

modern userspace applications, like OVN, can configure the TC datapath to
"recirculate" packets several times. If more than 4 "recirculation" rules
are configured, packets can be dropped by __tcf_classify().
Changing the maximum number of reclassifications (from 4 to 16) should be
sufficient to prevent drops in most use cases, and guard against loops at
the same time.
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With recent changes that separated action module load from action
initialization tcf_action_init() function error handling code was modified
to manually release the loaded modules if loading/initialization of any
further action in same batch failed. For the case when all modules
successfully loaded and some of the actions were initialized before one of
them failed in init handler. In this case for all previous actions the
module will be released twice by the error handler: First time by the loop
that manually calls module_put() for all ops, and second time by the action
destroy code that puts the module after destroying the action.

Reproduction:

$ sudo tc actions add action simple sdata \"2\" index 2
$ sudo tc actions add action simple sdata \"1\" index 1 \
                      action simple sdata \"2\" index 2
RTNETLINK answers: File exists
We have an error talking to the kernel
$ sudo tc actions ls action simple
total acts 1

        action order 0: Simple <"2">
         index 2 ref 1 bind 0
$ sudo tc actions flush action simple
$ sudo tc actions ls action simple
$ sudo tc actions add action simple sdata \"2\" index 2
Error: Failed to load TC action module.
We have an error talking to the kernel
$ lsmod | grep simple
act_simple             20480  -1

Fix the issue by modifying module reference counting handling in action
initialization code:

- Get module reference in tcf_idr_create() and put it in tcf_idr_release()
instead of taking over the reference held by the caller.

- Modify users of tcf_action_init_1() to always release the module
reference which they obtain before calling init function instead of
assuming that created action takes over the reference.

- Finally, modify tcf_action_init_1() to not release the module reference
when overwriting existing action as this is no longer necessary since both
upper and lower layers obtain and manage their own module references
independently.

Fixes: d349f997 ("net_sched: fix RTNL deadlock again caused by request_module()")
Suggested-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Action init code increments reference counter when it changes an action.
This is the desired behavior for cls API which needs to obtain action
reference for every classifier that points to action. However, act API just
needs to change the action and releases the reference before returning.
This sequence breaks when the requested action doesn't exist, which causes
act API init code to create new action with specified index, but action is
still released before returning and is deleted (unless it was referenced
concurrently by cls API).

Reproduction:

$ sudo tc actions ls action gact
$ sudo tc actions change action gact drop index 1
$ sudo tc actions ls action gact

Extend tcf_action_init() to accept 'init_res' array and initialize it with
action->ops->init() result. In tcf_action_add() remove pointers to created
actions from actions array before passing it to tcf_action_put_many().

Fixes: cae422f3 ("net: sched: use reference counting action init")
Reported-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The 'unlocked_driver_cb' struct field in 'bo' is not being initialized
in tcf_block_offload_init(). The uninitialized 'unlocked_driver_cb'
will be used when calling unlocked_driver_cb(). So initialize 'bo' to
zero to avoid the issue.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: 0fdcf78d ("net: use flow_indr_dev_setup_offload()")
Signed-off-by: NYunjian Wang <wangyunjian@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When openvswitch conntrack offload with act_ct action. The first rule
do conntrack in the act_ct in tc subsystem. And miss the next rule in
the tc and fallback to the ovs datapath but miss set post_ct flag
which will lead the ct_state_key with -trk flag.

Fixes: 7baf2429 ("net/sched: cls_flower add CT_FLAGS_INVALID flag support")
Signed-off-by: Nwenxu <wenxu@ucloud.cn>
Reviewed-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow flow_offload API to configure packet-per-second policing using rate
and burst parameters.

Dummy implementations of tcf_police_rate_pkt_ps() and
tcf_police_burst_pkt() are supplied which return 0, the unconfigured state.
This is to facilitate splitting the offload, driver, and TC code portion of
this feature into separate patches with the aim of providing a logical flow
for review. And the implementation of these helpers will be filled out by a
follow-up patch.
Signed-off-by: NXingfeng Hu <xingfeng.hu@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NLouis Peens <louis.peens@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When police action is created by cls API tcf_exts_validate() first
conditional that calls tcf_action_init_1() directly, the action idr is not
updated according to latest changes in action API that require caller to
commit newly created action to idr with tcf_idr_insert_many(). This results
such action not being accessible through act API and causes crash reported
by syzbot:

==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:71 [inline]
BUG: KASAN: null-ptr-deref in atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
BUG: KASAN: null-ptr-deref in __tcf_idr_release net/sched/act_api.c:178 [inline]
BUG: KASAN: null-ptr-deref in tcf_idrinfo_destroy+0x129/0x1d0 net/sched/act_api.c:598
Read of size 4 at addr 0000000000000010 by task kworker/u4:5/204

CPU: 0 PID: 204 Comm: kworker/u4:5 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 __kasan_report mm/kasan/report.c:400 [inline]
 kasan_report.cold+0x5f/0xd5 mm/kasan/report.c:413
 check_memory_region_inline mm/kasan/generic.c:179 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:185
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
 __tcf_idr_release net/sched/act_api.c:178 [inline]
 tcf_idrinfo_destroy+0x129/0x1d0 net/sched/act_api.c:598
 tc_action_net_exit include/net/act_api.h:151 [inline]
 police_exit_net+0x168/0x360 net/sched/act_police.c:390
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:190
 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:604
 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 204 Comm: kworker/u4:5 Tainted: G    B             5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 panic+0x306/0x73d kernel/panic.c:231
 end_report+0x58/0x5e mm/kasan/report.c:100
 __kasan_report mm/kasan/report.c:403 [inline]
 kasan_report.cold+0x67/0xd5 mm/kasan/report.c:413
 check_memory_region_inline mm/kasan/generic.c:179 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:185
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
 __tcf_idr_release net/sched/act_api.c:178 [inline]
 tcf_idrinfo_destroy+0x129/0x1d0 net/sched/act_api.c:598
 tc_action_net_exit include/net/act_api.h:151 [inline]
 police_exit_net+0x168/0x360 net/sched/act_police.c:390
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:190
 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:604
 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Kernel Offset: disabled

Fix the issue by calling tcf_idr_insert_many() after successful action
initialization.

Fixes: 0fedc63f ("net_sched: commit action insertions together")
Reported-by: syzbot+151e3e714d34ae4ce7e8@syzkaller.appspotmail.com
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Reviewed-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcf_action_init_1() loads tc action modules automatically with
request_module() after parsing the tc action names, and it drops RTNL
lock and re-holds it before and after request_module(). This causes a
lot of troubles, as discovered by syzbot, because we can be in the
middle of batch initializations when we create an array of tc actions.

One of the problem is deadlock:

CPU 0					CPU 1
rtnl_lock();
for (...) {
  tcf_action_init_1();
    -> rtnl_unlock();
    -> request_module();
				rtnl_lock();
				for (...) {
				  tcf_action_init_1();
				    -> tcf_idr_check_alloc();
				   // Insert one action into idr,
				   // but it is not committed until
				   // tcf_idr_insert_many(), then drop
				   // the RTNL lock in the _next_
				   // iteration
				   -> rtnl_unlock();
    -> rtnl_lock();
    -> a_o->init();
      -> tcf_idr_check_alloc();
      // Now waiting for the same index
      // to be committed
				    -> request_module();
				    -> rtnl_lock()
				    // Now waiting for RTNL lock
				}
				rtnl_unlock();
}
rtnl_unlock();

This is not easy to solve, we can move the request_module() before
this loop and pre-load all the modules we need for this netlink
message and then do the rest initializations. So the loop breaks down
to two now:

        for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
                struct tc_action_ops *a_o;

                a_o = tc_action_load_ops(name, tb[i]...);
                ops[i - 1] = a_o;
        }

        for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
                act = tcf_action_init_1(ops[i - 1]...);
        }

Although this looks serious, it only has been reported by syzbot, so it
seems hard to trigger this by humans. And given the size of this patch,
I'd suggest to make it to net-next and not to backport to stable.

This patch has been tested by syzbot and tested with tdc.py by me.

Fixes: 0fedc63f ("net_sched: commit action insertions together")
Reported-and-tested-by: syzbot+82752bc5331601cf4899@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+b3b63b6bff456bd95294@syzkaller.appspotmail.com
Reported-by: syzbot+ba67b12b1ca729912834@syzkaller.appspotmail.com
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <cong.wang@bytedance.com>
Tested-by: NJamal Hadi Salim <jhs@mojatatu.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20210117005657.14810-1-xiyou.wangcong@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Functions tfilter_notify_chain() and tcf_get_next_proto() are always called
with rtnl lock held in current implementation. Moreover, attempting to call
them without rtnl lock would cause a warning down the call chain in
function __tcf_get_next_proto() that requires the lock to be held by
callers. Remove the 'rtnl_held' argument in order to simplify the code and
make rtnl lock requirement explicit.
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Link: https://lore.kernel.org/r/20201127151205.23492-1-vladbu@nvidia.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Calls to nla_strlcpy are now replaced by calls to nla_strscpy which is the new
name of this function.
Signed-off-by: NFrancis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

nla_strlcpy now returns -E2BIG if src was truncated when written to dst.
It also returns this error value if dstsize is 0 or higher than INT_MAX.

For example, if src is "foo\0" and dst is 3 bytes long, the result will be:
1. "foG" after memcpy (G means garbage).
2. "fo\0" after memset.
3. -E2BIG is returned because src was not completely written into dst.

The callers of nla_strlcpy were modified to take into account this modification.
Signed-off-by: NFrancis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

make clang-analyzer on x86_64 defconfig caught my attention with:

net/sched/cls_api.c:2964:3: warning: Value stored to 'parent' is never read
  [clang-analyzer-deadcode.DeadStores]
                parent = 0;
                ^

net/sched/cls_api.c:2977:4: warning: Value stored to 'parent' is never read
  [clang-analyzer-deadcode.DeadStores]
                        parent = q->handle;
                        ^

Commit 32a4f5ec ("net: sched: introduce chain object to uapi")
introduced tc_dump_chain() and this initial implementation already
contained these unneeded dead stores.

Simplify the code to make clang-analyzer happy.

As compilers will detect these unneeded assignments and optimize this
anyway, the resulting binary is identical before and after this change.

No functional change. No change in object code.
Signed-off-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20201028113533.26160-1-lukas.bulwahn@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

The tcf_block_unbind() expects that the caller will take block->cb_lock
before calling it, however the code took RTNL lock and dropped cb_lock
instead. This causes to the following kernel panic.

 WARNING: CPU: 1 PID: 13524 at net/sched/cls_api.c:1488 tcf_block_unbind+0x2db/0x420
 Modules linked in: mlx5_ib mlx5_core mlxfw ptp pps_core act_mirred act_tunnel_key cls_flower vxlan ip6_udp_tunnel udp_tunnel dummy sch_ingress openvswitch nsh xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xt_addrtype iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_iscsi ib_umad ib_ipoib rdma_cm iw_cm ib_cm ib_uverbs ib_core overlay [last unloaded: mlxfw]
 CPU: 1 PID: 13524 Comm: test-ecmp-add-v Tainted: G        W         5.9.0+ #1
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 RIP: 0010:tcf_block_unbind+0x2db/0x420
 Code: ff 48 83 c4 40 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8d bc 24 30 01 00 00 be ff ff ff ff e8 7d 7f 70 00 85 c0 0f 85 7b fd ff ff <0f> 0b e9 74 fd ff ff 48 c7 c7 dc 6a 24 84 e8 02 ec fe fe e9 55 fd
 RSP: 0018:ffff888117d17968 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffff88812f713c00 RCX: 1ffffffff0848d5b
 RDX: 0000000000000001 RSI: ffff88814fbc8130 RDI: ffff888107f2b878
 RBP: 1ffff11022fa2f3f R08: 0000000000000000 R09: ffffffff84115a87
 R10: fffffbfff0822b50 R11: ffff888107f2b898 R12: ffff88814fbc8000
 R13: ffff88812f713c10 R14: ffff888117d17a38 R15: ffff88814fbc80c0
 FS:  00007f6593d36740(0000) GS:ffff8882a4f00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00005607a00758f8 CR3: 0000000131aea006 CR4: 0000000000170ea0
 Call Trace:
  tc_block_indr_cleanup+0x3e0/0x5a0
  ? tcf_block_unbind+0x420/0x420
  ? __mutex_unlock_slowpath+0xe7/0x610
  flow_indr_dev_unregister+0x5e2/0x930
  ? mlx5e_restore_tunnel+0xdf0/0xdf0 [mlx5_core]
  ? mlx5e_restore_tunnel+0xdf0/0xdf0 [mlx5_core]
  ? flow_indr_block_cb_alloc+0x3c0/0x3c0
  ? mlx5_db_free+0x37c/0x4b0 [mlx5_core]
  mlx5e_cleanup_rep_tx+0x8b/0xc0 [mlx5_core]
  mlx5e_detach_netdev+0xe5/0x120 [mlx5_core]
  mlx5e_vport_rep_unload+0x155/0x260 [mlx5_core]
  esw_offloads_disable+0x227/0x2b0 [mlx5_core]
  mlx5_eswitch_disable_locked.cold+0x38e/0x699 [mlx5_core]
  mlx5_eswitch_disable+0x94/0xf0 [mlx5_core]
  mlx5_device_disable_sriov+0x183/0x1f0 [mlx5_core]
  mlx5_core_sriov_configure+0xfd/0x230 [mlx5_core]
  sriov_numvfs_store+0x261/0x2f0
  ? sriov_drivers_autoprobe_store+0x110/0x110
  ? sysfs_file_ops+0x170/0x170
  ? sysfs_file_ops+0x117/0x170
  ? sysfs_file_ops+0x170/0x170
  kernfs_fop_write+0x1ff/0x3f0
  ? rcu_read_lock_any_held+0x6e/0x90
  vfs_write+0x1f3/0x620
  ksys_write+0xf9/0x1d0
  ? __x64_sys_read+0xb0/0xb0
  ? lockdep_hardirqs_on_prepare+0x273/0x3f0
  ? syscall_enter_from_user_mode+0x1d/0x50
  do_syscall_64+0x2d/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

<...>

 ---[ end trace bfdd028ada702879 ]---

Fixes: 0fdcf78d ("net: use flow_indr_dev_setup_offload()")
Signed-off-by: NLeon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20201026123327.1141066-1-leon@kernel.orgSigned-off-by: NJakub Kicinski <kuba@kernel.org>

We need to jump to the "err_out_locked" label when
tcf_gate_get_entries() fails. Otherwise, tc_setup_flow_action() exits
with ->tcfa_lock still held.

Fixes: d29bdd69 ("net: schedule: add action gate offloading")
Signed-off-by: NGuillaume Nault <gnault@redhat.com>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Link: https://lore.kernel.org/r/12f60e385584c52c22863701c0185e40ab08a7a7.1603207948.git.gnault@redhat.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

When openvswitch conntrack offload with act_ct action. Fragment packets
defrag in the ingress tc act_ct action and miss the next chain. Then the
packet pass to the openvswitch datapath without the mru. The over
mtu packet will be dropped in output action in openvswitch for over mtu.

"kernel: net2: dropped over-mtu packet: 1528 > 1500"

This patch add mru in the tc_skb_ext for adefrag and miss next chain
situation. And also add mru in the qdisc_skb_cb. The act_ct set the mru
to the qdisc_skb_cb when the packet defrag. And When the chain miss,
The mru is set to tc_skb_ext which can be got by ovs datapath.

Fixes: b57dc7c1 ("net/sched: Introduce action ct")
Signed-off-by: Nwenxu <wenxu@ucloud.cn>
Reviewed-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I noticed that touching linux/rhashtable.h causes lib/vsprintf.c to
be rebuilt.  This dependency came through a bogus inclusion in the
file net/flow_offload.h.  This patch moves it to the right place.

This patch also removes a lingering rhashtable inclusion in cls_api
created by the same commit.

Fixes: 4e481908 ("flow_offload: move tc indirect block to...")
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>