Currently it is possible to craft a special netlink RTM_NEWQDISC
command that can result in jitter being equal to 0x80000000. It is
enough to set the 32 bit jitter to 0x02000000 (it will later be
multiplied by 2^6) or just set the 64 bit jitter via
TCA_NETEM_JITTER64. This causes an overflow during the generation of
uniformly distributed numbers in tabledist(), which in turn leads to
division by zero (sigma != 0, but sigma * 2 is 0).

The related fragment of code needs 32-bit division - see commit
9b0ed891 ("netem: remove unnecessary 64 bit modulus"), so switching to
64 bit is not an option.

Fix the issue by keeping the value of jitter within the range that can
be adequately handled by tabledist() - [0;INT_MAX]. As negative std
deviation makes no sense, take the absolute value of the passed value
and cap it at INT_MAX. Inside tabledist(), switch to unsigned 32 bit
arithmetic in order to prevent overflows.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: NAleksandr Nogikh <nogikh@google.com>
Reported-by: syzbot+ec762a6342ad0d3c0d8f@syzkaller.appspotmail.com
Acked-by: NStephen Hemminger <stephen@networkplumber.org>
Link: https://lore.kernel.org/r/20201028170731.1383332-1-aleksandrnogikh@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>

TCA_MPLS_ACT_PUSH and TCA_MPLS_ACT_MAC_PUSH might be used on gso
packets. Such packets will thus require mpls_gso.ko for segmentation.

v2: Drop dependency on CONFIG_NET_MPLS_GSO in Kconfig (from Jakub and
    David).

Fixes: 2a2ea508 ("net: sched: add mpls manipulation actions to TC")
Signed-off-by: NGuillaume Nault <gnault@redhat.com>
Link: https://lore.kernel.org/r/1f6cab15bbd15666795061c55563aaf6a386e90e.1603708007.git.gnault@redhat.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

the following command

 # tc action add action tunnel_key \
 > set src_ip 2001:db8::1 dst_ip 2001:db8::2 id 10 erspan_opts 1:6789:0:0

generates the following splat:

 BUG: KASAN: slab-out-of-bounds in tunnel_key_copy_opts+0xcc9/0x1010 [act_tunnel_key]
 Write of size 4 at addr ffff88813f5f1cc8 by task tc/873

 CPU: 2 PID: 873 Comm: tc Not tainted 5.9.0+ #282
 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014
 Call Trace:
  dump_stack+0x99/0xcb
  print_address_description.constprop.7+0x1e/0x230
  kasan_report.cold.13+0x37/0x7c
  tunnel_key_copy_opts+0xcc9/0x1010 [act_tunnel_key]
  tunnel_key_init+0x160c/0x1f40 [act_tunnel_key]
  tcf_action_init_1+0x5b5/0x850
  tcf_action_init+0x15d/0x370
  tcf_action_add+0xd9/0x2f0
  tc_ctl_action+0x29b/0x3a0
  rtnetlink_rcv_msg+0x341/0x8d0
  netlink_rcv_skb+0x120/0x380
  netlink_unicast+0x439/0x630
  netlink_sendmsg+0x719/0xbf0
  sock_sendmsg+0xe2/0x110
  ____sys_sendmsg+0x5ba/0x890
  ___sys_sendmsg+0xe9/0x160
  __sys_sendmsg+0xd3/0x170
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f872a96b338
 Code: 89 02 48 c7 c0 ff ff ff ff eb b5 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 8d 05 25 43 2c 00 8b 00 85 c0 75 17 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 41 54 41 89 d4 55
 RSP: 002b:00007ffffe367518 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
 RAX: ffffffffffffffda RBX: 000000005f8f5aed RCX: 00007f872a96b338
 RDX: 0000000000000000 RSI: 00007ffffe367580 RDI: 0000000000000003
 RBP: 0000000000000000 R08: 0000000000000001 R09: 000000000000001c
 R10: 000000000000000b R11: 0000000000000246 R12: 0000000000000001
 R13: 0000000000686760 R14: 0000000000000601 R15: 0000000000000000

 Allocated by task 873:
  kasan_save_stack+0x19/0x40
  __kasan_kmalloc.constprop.7+0xc1/0xd0
  __kmalloc+0x151/0x310
  metadata_dst_alloc+0x20/0x40
  tunnel_key_init+0xfff/0x1f40 [act_tunnel_key]
  tcf_action_init_1+0x5b5/0x850
  tcf_action_init+0x15d/0x370
  tcf_action_add+0xd9/0x2f0
  tc_ctl_action+0x29b/0x3a0
  rtnetlink_rcv_msg+0x341/0x8d0
  netlink_rcv_skb+0x120/0x380
  netlink_unicast+0x439/0x630
  netlink_sendmsg+0x719/0xbf0
  sock_sendmsg+0xe2/0x110
  ____sys_sendmsg+0x5ba/0x890
  ___sys_sendmsg+0xe9/0x160
  __sys_sendmsg+0xd3/0x170
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

 The buggy address belongs to the object at ffff88813f5f1c00
  which belongs to the cache kmalloc-256 of size 256
 The buggy address is located 200 bytes inside of
  256-byte region [ffff88813f5f1c00, ffff88813f5f1d00)
 The buggy address belongs to the page:
 page:0000000011b48a19 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13f5f0
 head:0000000011b48a19 order:1 compound_mapcount:0
 flags: 0x17ffffc0010200(slab|head)
 raw: 0017ffffc0010200 0000000000000000 0000000d00000001 ffff888107c43400
 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  ffff88813f5f1b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff88813f5f1c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 >ffff88813f5f1c80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
                                               ^
  ffff88813f5f1d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff88813f5f1d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

using IPv6 tunnels, act_tunnel_key allocates a fixed amount of memory for
the tunnel metadata, but then it expects additional bytes to store tunnel
specific metadata with tunnel_key_copy_opts().

Fix the arguments of __ipv6_tun_set_dst(), so that 'md_size' contains the
size previously computed by tunnel_key_get_opts_len(), like it's done for
IPv4 tunnels.

Fixes: 0ed5269f ("net/sched: add tunnel option support to act_tunnel_key")
Reported-by: NShuang Li <shuali@redhat.com>
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Link: https://lore.kernel.org/r/36ebe969f6d13ff59912d6464a4356fe6f103766.1603231100.git.dcaratti@redhat.comSigned-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>

Need to use the udp header type and not tcp.

Fixes: 9c26ba9b ("net/sched: act_ct: Instantiate flow table entry actions")
Signed-off-by: NRoi Dayan <roid@nvidia.com>
Reviewed-by: NPaul Blakey <paulb@nvidia.com>
Link: https://lore.kernel.org/r/20201019090244.3015186-1-roid@nvidia.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

kmalloc() of sufficiently big portion of memory is cache-aligned
in regular conditions. If some debugging options are used,
there is no reason qdisc structures would need 64-byte alignment
if most other kernel structures are not aligned.

This get rid of QDISC_ALIGN and QDISC_ALIGNTO.

Addition of privdata field will help implementing
the reverse of qdisc_priv() and documents where
the private data is.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Allen Pais <allen.lkml@gmail.com>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Although we take RTNL on dump path, it is possible to
skip RTNL on insertion path. So the following race condition
is possible:

rtnl_lock()		// no rtnl lock
			mutex_lock(&idrinfo->lock);
			// insert ERR_PTR(-EBUSY)
			mutex_unlock(&idrinfo->lock);
tc_dump_action()
rtnl_unlock()

So we have to skip those temporary -EBUSY entries on dump path
too.

Reported-and-tested-by: syzbot+b47bc4f247856fb4d9e1@syzkaller.appspotmail.com
Fixes: 0fedc63f ("net_sched: commit action insertions together")
Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Define the MAC_PUSH action which pushes an MPLS LSE before the mac
header (instead of between the mac and the network headers as the
plain PUSH action does).

The only special case is when the skb has an offloaded VLAN. In that
case, it has to be inlined before pushing the MPLS header.
Signed-off-by: NGuillaume Nault <gnault@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement TCA_VLAN_ACT_POP_ETH and TCA_VLAN_ACT_PUSH_ETH, to
respectively pop and push a base Ethernet header at the beginning of a
frame.

POP_ETH is just a matter of pulling ETH_HLEN bytes. VLAN tags, if any,
must be stripped before calling POP_ETH.

PUSH_ETH is restricted to skbs with no mac_header, and only the MAC
addresses can be configured. The Ethertype is automatically set from
skb->protocol. These restrictions ensure that all skb's fields remain
consistent, so that this action can't confuse other part of the
networking stack (like GSO).

Since openvswitch already had these actions, consolidate the code in
skbuff.c (like for vlan and mpls push/pop).
Signed-off-by: NGuillaume Nault <gnault@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].

Refactor the code according to the use of a flexible-array member in
struct tc_u_hnode and use the struct_size() helper to calculate the
size for the allocations. Commit 5778d39d ("net_sched: fix struct
tc_u_hnode layout in u32") makes it clear that the code is expected to
dynamically allocate divisor + 1 entries for ->ht[] in tc_uhnode. Also,
based on other observations, as the piece of code below:

1232                 for (h = 0; h <= ht->divisor; h++) {
1233                         for (n = rtnl_dereference(ht->ht[h]);
1234                              n;
1235                              n = rtnl_dereference(n->next)) {
1236                                 if (tc_skip_hw(n->flags))
1237                                         continue;
1238
1239                                 err = u32_reoffload_knode(tp, n, add, cb,
1240                                                           cb_priv, extack);
1241                                 if (err)
1242                                         return err;
1243                         }
1244                 }

we can assume that, in general, the code is actually expecting to allocate
that extra space for the one-element array in tc_uhnode, everytime it
allocates memory for instances of tc_uhnode or tc_u_common structures.
That's the reason for passing '1' as the last argument for struct_size()
in the allocation for _root_ht_ and _tp_c_, and 'divisor + 1' in the
allocation code for _ht_.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arraysTested-by: Nkernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/5f7062af.z3T9tn9yIPv6h5Ny%25lkp@intel.com/Signed-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All TC actions call tcf_action_check_ctrlact() to validate
goto chain, so this check in tcf_action_init_1() is actually
redundant. Remove it to save troubles of leaking memory.

Fixes: e49d8c22 ("net_sched: defer tcf_idr_insert() in tcf_action_init_1()")
Reported-by: NVlad Buslov <vladbu@mellanox.com>
Suggested-by: NDavide Caratti <dcaratti@redhat.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

syzbot is able to trigger a failure case inside the loop in
tcf_action_init(), and when this happens we clean up with
tcf_action_destroy(). But, as these actions are already inserted
into the global IDR, other parallel process could free them
before tcf_action_destroy(), then we will trigger a use-after-free.

Fix this by deferring the insertions even later, after the loop,
and committing all the insertions in a separate loop, so we will
never fail in the middle of the insertions any more.

One side effect is that the window between alloction and final
insertion becomes larger, now it is more likely that the loop in
tcf_del_walker() sees the placeholder -EBUSY pointer. So we have
to check for error pointer in tcf_del_walker().

Reported-and-tested-by: syzbot+2287853d392e4b42374a@syzkaller.appspotmail.com
Fixes: 0190c1d4 ("net: sched: atomically check-allocate action")
Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All TC actions call tcf_idr_insert() for new action at the end
of their ->init(), so we can actually move it to a central place
in tcf_action_init_1().

And once the action is inserted into the global IDR, other parallel
process could free it immediately as its refcnt is still 1, so we can
not fail after this, we need to move it after the goto action
validation to avoid handling the failure case after insertion.

This is found during code review, is not directly triggered by syzbot.
And this prepares for the next patch.

Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In fl_set_erspan_opt(), all bits of erspan md was set 1, as this
function is also used to set opt MASK. However, when setting for
md->u.index for opt VALUE, the rest bits of the union md->u will
be left 1. It would cause to fail the match of the whole md when
version is 1 and only index is set.

This patch is to fix by initializing with 0 before setting erspan
md->u.
Reported-by: NShuang Li <shuali@redhat.com>
Fixes: 79b1011c ("net: sched: allow flower to match erspan options")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As we can see from vxlan_build/parse_gbp_hdr(), when processing metadata
on vxlan rx/tx path, only dont_learn/policy_applied/policy_id fields can
be set to or parse from the packet for vxlan gbp option.

So we'd better do the mask when set it in act_tunnel_key and cls_flower.
Otherwise, when users don't know these bits, they may configure with a
value which can never be matched.
Reported-by: NShuang Li <shuali@redhat.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It's possible that the user specifies an interval that couldn't allow
any packet to be transmitted. This also avoids the issue of the
hrtimer handler starving the other threads because it's running too
often.

The solution is to reject interval sizes that according to the current
link speed wouldn't allow any packet to be transmitted.

Reported-by: syzbot+8267241609ae8c23b248@syzkaller.appspotmail.com
Fixes: 5a781ccb ("tc: Add support for configuring the taprio scheduler")
Signed-off-by: NVinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently there is concurrent reset and enqueue operation for the
same lockless qdisc when there is no lock to synchronize the
q->enqueue() in __dev_xmit_skb() with the qdisc reset operation in
qdisc_deactivate() called by dev_deactivate_queue(), which may cause
out-of-bounds access for priv->ring[] in hns3 driver if user has
requested a smaller queue num when __dev_xmit_skb() still enqueue a
skb with a larger queue_mapping after the corresponding qdisc is
reset, and call hns3_nic_net_xmit() with that skb later.

Reused the existing synchronize_net() in dev_deactivate_many() to
make sure skb with larger queue_mapping enqueued to old qdisc(which
is saved in dev_queue->qdisc_sleeping) will always be reset when
dev_reset_queue() is called.

Fixes: 6b3ba914 ("net: sched: allow qdiscs to handle locking")
Signed-off-by: NYunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reviewing the error handling in tcf_action_init_1()
most of the early handling uses

err_out:
	if (cookie) {
		kfree(cookie->data);
		kfree(cookie);
	}

before cookie could ever be set.

So skip the unnecessay check.
Signed-off-by: NTom Rix <trix@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The following deadlock scenario is triggered by syzbot:

Thread A:				Thread B:
tcf_idr_check_alloc()
...
populate_metalist()
  rtnl_unlock()
					rtnl_lock()
					...
  request_module()			tcf_idr_check_alloc()
  rtnl_lock()

At this point, thread A is waiting for thread B to release RTNL
lock, while thread B is waiting for thread A to commit the IDR
change with tcf_idr_insert() later.

Break this deadlock situation by preloading ife modules earlier,
before tcf_idr_check_alloc(), this is fine because we only need
to load modules we need potentially.

Reported-and-tested-by: syzbot+80e32b5d1f9923f8ace6@syzkaller.appspotmail.com
Fixes: 0190c1d4 ("net: sched: atomically check-allocate action")
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

When ->init() fails, ->destroy() is called to clean up.
So it is unnecessary to clean up in red_init(), and it
would cause some refcount underflow.

Fixes: aee9caa0 ("net: sched: sch_red: Add qevents "early_drop" and "mark"")
Reported-and-tested-by: syzbot+b33c1cb0a30ebdc8a5f9@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+e5ea5f8a3ecfd4427a1c@syzkaller.appspotmail.com
Cc: Petr Machata <petrm@mellanox.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: NPetr Machata <petrm@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 9c66d156 ("taprio: Add support for hardware
offloading") there's a bit of inconsistency when offloading schedules
to the hardware:

In software mode, the gate masks are specified in terms of traffic
classes, so if say "sched-entry S 03 20000", it means that the traffic
classes 0 and 1 are open for 20us; when taprio is offloaded to
hardware, the gate masks are specified in terms of hardware queues.

The idea here is to fix hardware offloading, so schedules in hardware
and software mode have the same behavior. What's needed to do is to
map traffic classes to queues when applying the offload to the driver.

Fixes: 9c66d156 ("taprio: Add support for hardware offloading")
Signed-off-by: NVinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-throughSigned-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>

tcf_ct_handle_fragments() shouldn't free the skb when ip_defrag() call
fails. Otherwise, we will cause a double-free bug.
In such cases, just return the error to the caller.

Fixes: b57dc7c1 ("net/sched: Introduce action ct")
Signed-off-by: NAlaa Hleihel <alaa@mellanox.com>
Reviewed-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change places that open-code NLA_POLICY_EXACT_LEN() to
use the macro instead, giving us flexibility in how we
handle the details of the macro.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Acked-by: NMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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>

Make use of the struct_size() helper, in multiple places, instead
of an open-coded version in order to avoid any potential type
mistakes and protect against potential integer overflows.

Also, remove unnecessary object identifier size.
Signed-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Exchange the positions of the err_tbl_init and err_register labels in
ct_init_module function.

Fixes: c34b961a ("net/sched: act_ct: Create nf flow table per zone")
Signed-off-by: Nliujian <liujian56@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make use of the flex_array_size() helper to calculate the size of a
flexible array member within an enclosing structure.

This helper offers defense-in-depth against potential integer
overflows, while at the same time makes it explicitly clear that
we are dealing with a flexible array member.
Signed-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When red_init() fails, red_destroy() is called to clean up.
If the timer is not initialized yet, del_timer_sync() will
complain. So we have to move timer_setup() before any failure.

Reported-and-tested-by: syzbot+6e95a4fabf88dc217145@syzkaller.appspotmail.com
Fixes: aee9caa0 ("net: sched: sch_red: Add qevents "early_drop" and "mark"")
Cc: Petr Machata <petrm@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adding new cls flower keys for hash value and hash
mask and dissect the hash info from the skb into
the flow key towards flow classication.
Signed-off-by: NAriel Levkovich <lariel@mellanox.com>
Reviewed-by: NJiri Pirko <jiri@mellanox.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>

The fragment packets do defrag in tcf_ct_handle_fragments
will clear the skb->cb which make the qdisc_skb_cb clear
too. So the qdsic_skb_cb should be store before defrag and
restore after that.
It also update the pkt_len after all the
fragments finish the defrag to one packet and make the
following actions counter correct.

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

In case the qdisc_match_from_root function() is called from non-rcu path
with rtnl mutex held, a suspiciout rcu usage warning appears:

[  241.504354] =============================
[  241.504358] WARNING: suspicious RCU usage
[  241.504366] 5.8.0-rc4-custom-01521-g72a7c7d549c3 #32 Not tainted
[  241.504370] -----------------------------
[  241.504378] net/sched/sch_api.c:270 RCU-list traversed in non-reader section!!
[  241.504382]
               other info that might help us debug this:
[  241.504388]
               rcu_scheduler_active = 2, debug_locks = 1
[  241.504394] 1 lock held by tc/1391:
[  241.504398]  #0: ffffffff85a27850 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0
[  241.504431]
               stack backtrace:
[  241.504440] CPU: 0 PID: 1391 Comm: tc Not tainted 5.8.0-rc4-custom-01521-g72a7c7d549c3 #32
[  241.504446] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
[  241.504453] Call Trace:
[  241.504465]  dump_stack+0x100/0x184
[  241.504482]  lockdep_rcu_suspicious+0x153/0x15d
[  241.504499]  qdisc_match_from_root+0x293/0x350

Fix this by passing the rtnl held lockdep condition down to
hlist_for_each_entry_rcu()
Reported-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit aebe4426.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Mirred currently does not mix well with blocks executed after the qdisc
root lock is taken. This includes classification blocks (such as in PRIO,
ETS, DRR qdiscs) and qevents. The locking caused by the packet mirrored by
mirred can cause deadlocks: either when the thread of execution attempts to
take the lock a second time, or when two threads end up waiting on each
other's locks.

The qevent patchset attempted to not introduce further badness of this
sort, and dropped the lock before executing the qevent block. However this
lead to too little locking and races between qdisc configuration and packet
enqueue in the RED qdisc.

Before the deadlock issues are solved in a way that can be applied across
many qdiscs reasonably easily, do for qevents what is done for the
classification blocks and just keep holding the root lock.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: NKees Cook <keescook@chromium.org>

Previously, shared blocks were only relevant for the pseudo-qdiscs ingress
and clsact. Recently, a qevent facility was introduced, which allows to
bind blocks to well-defined slots of a qdisc instance. RED in particular
got two qevents: early_drop and mark. Drivers that wish to offload these
blocks will be sent the usual notification, and need to know which qdisc it
is related to.

To that end, extend flow_block_offload with a "sch" pointer, and initialize
as appropriate. This prompts changes in the indirect block facility, which
now tracks the scheduler in addition to the netdevice. Update signatures of
several functions similarly.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Simple fixes which require no deep knowledge of the code.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When tcf_block_get() fails inside atm_tc_init(),
atm_tc_put() is called to release the qdisc p->link.q.
But the flow->ref prevents it to do so, as the flow->ref
is still zero.

Fix this by moving the p->link.ref initialization before
tcf_block_get().

Fixes: 6529eaba ("net: sched: introduce tcf block infractructure")
Reported-and-tested-by: syzbot+d411cff6ab29cc2c311b@syzkaller.appspotmail.com
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>