<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/net/sched, branch linux-5.16.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.16.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.16.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2022-04-08T12:06:31Z</updated>
<entry>
<title>net/sched: act_ct: fix ref leak when switching zones</title>
<updated>2022-04-08T12:06:31Z</updated>
<author>
<name>Marcelo Ricardo Leitner</name>
</author>
<published>2022-03-24T19:22:10Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=4bb42d73def9411e5cad885b9811987d72431df1'/>
<id>urn:sha1:4bb42d73def9411e5cad885b9811987d72431df1</id>
<content type='text'>
[ Upstream commit bcb74e132a76ce0502bb33d5b65533a4ed72d159 ]

When switching zones or network namespaces without doing a ct clear in
between, it is now leaking a reference to the old ct entry. That's
because tcf_ct_skb_nfct_cached() returns false and
tcf_ct_flow_table_lookup() may simply overwrite it.

The fix is to, as the ct entry is not reusable, free it already at
tcf_ct_skb_nfct_cached().

Reported-by: Florian Westphal &lt;fw@strlen.de&gt;
Fixes: 2f131de361f6 ("net/sched: act_ct: Fix flow table lookup after ct clear or switching zones")
Signed-off-by: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>net: prefer nf_ct_put instead of nf_conntrack_put</title>
<updated>2022-04-08T12:06:31Z</updated>
<author>
<name>Florian Westphal</name>
</author>
<published>2022-01-07T04:03:26Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=bdd85776abe4946ca728d2fc7b3f12b660bbf4c5'/>
<id>urn:sha1:bdd85776abe4946ca728d2fc7b3f12b660bbf4c5</id>
<content type='text'>
[ Upstream commit 408bdcfce8dfd6902f75fbcd3b99d8b24b506597 ]

Its the same as nf_conntrack_put(), but without the
need for an indirect call.  The downside is a module dependency on
nf_conntrack, but all of these already depend on conntrack anyway.

Cc: Paul Blakey &lt;paulb@mellanox.com&gt;
Cc: dev@openvswitch.org
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>net/sched: act_ct: Fix flow table lookup after ct clear or switching zones</title>
<updated>2022-03-02T10:51:04Z</updated>
<author>
<name>Paul Blakey</name>
</author>
<published>2022-02-17T09:30:48Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=e9408de00e5ecd0dbe91cf061c7da23711c4febb'/>
<id>urn:sha1:e9408de00e5ecd0dbe91cf061c7da23711c4febb</id>
<content type='text'>
commit 2f131de361f6d0eaff17db26efdb844c178432f8 upstream.

Flow table lookup is skipped if packet either went through ct clear
action (which set the IP_CT_UNTRACKED flag on the packet), or while
switching zones and there is already a connection associated with
the packet. This will result in no SW offload of the connection,
and the and connection not being removed from flow table with
TCP teardown (fin/rst packet).

To fix the above, remove these unneccary checks in flow
table lookup.

Fixes: 46475bb20f4b ("net/sched: act_ct: Software offload of established flows")
Signed-off-by: Paul Blakey &lt;paulb@nvidia.com&gt;
Acked-by: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>net: sched: limit TC_ACT_REPEAT loops</title>
<updated>2022-02-23T11:06:03Z</updated>
<author>
<name>Eric Dumazet</name>
</author>
<published>2022-02-15T23:53:05Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=132de3a6cc19680bdd0d28cd5b79f91d0edb132f'/>
<id>urn:sha1:132de3a6cc19680bdd0d28cd5b79f91d0edb132f</id>
<content type='text'>
commit 5740d068909676d4bdb5c9c00c37a83df7728909 upstream.

We have been living dangerously, at the mercy of malicious users,
abusing TC_ACT_REPEAT, as shown by this syzpot report [1].

Add an arbitrary limit (32) to the number of times an action can
return TC_ACT_REPEAT.

v2: switch the limit to 32 instead of 10.
    Use net_warn_ratelimited() instead of pr_err_once().

[1] (C repro available on demand)

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu:    1-...!: (10500 ticks this GP) idle=021/1/0x4000000000000000 softirq=5592/5592 fqs=0
        (t=10502 jiffies g=5305 q=190)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g5305 f0x0 RCU_GP_WAIT_FQS(5) -&gt;state=0x402
rcu:    Possible timer handling issue on cpu=0 timer-softirq=3527
rcu: rcu_preempt kthread starved for 10505 jiffies! g5305 f0x0 RCU_GP_WAIT_FQS(5) -&gt;state=0x402 -&gt;cpu=0
rcu:    Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:29344 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 &lt;TASK&gt;
 context_switch kernel/sched/core.c:4986 [inline]
 __schedule+0xab2/0x4db0 kernel/sched/core.c:6295
 schedule+0xd2/0x260 kernel/sched/core.c:6368
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1963
 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2136
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 &lt;/TASK&gt;
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3646 Comm: syz-executor358 Not tainted 5.17.0-rc3-syzkaller-00149-gbf8e59fd315f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline]
RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:437 [inline]
RIP: 0010:__pv_queued_spin_lock_slowpath+0x3b8/0xb40 kernel/locking/qspinlock.c:508
Code: 48 89 eb c6 45 01 01 41 bc 00 80 00 00 48 c1 e9 03 83 e3 07 41 be 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 2c 01 eb 0c &lt;f3&gt; 90 41 83 ec 01 0f 84 72 04 00 00 41 0f b6 45 00 38 d8 7f 08 84
RSP: 0018:ffffc9000283f1b0 EFLAGS: 00000206
RAX: 0000000000000003 RBX: 0000000000000000 RCX: 1ffff1100fc0071e
RDX: 0000000000000001 RSI: 0000000000000201 RDI: 0000000000000000
RBP: ffff88807e0038f0 R08: 0000000000000001 R09: ffffffff8ffbf9ff
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000004c1e
R13: ffffed100fc0071e R14: 0000000000000001 R15: ffff8880b9c3aa80
FS:  00005555562bf300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdbfef12b8 CR3: 00000000723c2000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 &lt;TASK&gt;
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:115
 spin_lock_bh include/linux/spinlock.h:354 [inline]
 sch_tree_lock include/net/sch_generic.h:610 [inline]
 sch_tree_lock include/net/sch_generic.h:605 [inline]
 prio_tune+0x3b9/0xb50 net/sched/sch_prio.c:211
 prio_init+0x5c/0x80 net/sched/sch_prio.c:244
 qdisc_create.constprop.0+0x44a/0x10f0 net/sched/sch_api.c:1253
 tc_modify_qdisc+0x4c5/0x1980 net/sched/sch_api.c:1660
 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5594
 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+0x6e8/0x810 net/socket.c:2413
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496
 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: 0033:0x7f7ee98aae99
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 90 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 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdbfef12d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffdbfef1300 RCX: 00007f7ee98aae99
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d
R10: 000000000000000d R11: 0000000000000246 R12: 00007ffdbfef12f0
R13: 00000000000f4240 R14: 000000000004ca47 R15: 00007ffdbfef12e4
 &lt;/TASK&gt;
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.293 msecs
NMI backtrace for cpu 1
CPU: 1 PID: 3260 Comm: kworker/1:3 Not tainted 5.17.0-rc3-syzkaller-00149-gbf8e59fd315f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: mld mld_ifc_work
Call Trace:
 &lt;IRQ&gt;
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343
 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:688 [inline]
 rcu_pending kernel/rcu/tree.c:3919 [inline]
 rcu_sched_clock_irq.cold+0x5c/0x759 kernel/rcu/tree.c:2617
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 &lt;/IRQ&gt;
 &lt;TASK&gt;
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0xc/0x70 kernel/kcov.c:286
Code: 00 00 00 48 89 7c 30 e8 48 89 4c 30 f0 4c 89 54 d8 20 48 89 10 5b c3 0f 1f 80 00 00 00 00 41 89 f8 bf 03 00 00 00 4c 8b 14 24 &lt;89&gt; f1 65 48 8b 34 25 00 70 02 00 e8 14 f9 ff ff 84 c0 74 4b 48 8b
RSP: 0018:ffffc90002c5eea8 EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffff88801c625800 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: ffff8880137d3100 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff874fcd88 R11: 0000000000000000 R12: ffff88801d692dc0
R13: ffff8880137d3104 R14: 0000000000000000 R15: ffff88801d692de8
 tcf_police_act+0x358/0x11d0 net/sched/act_police.c:256
 tcf_action_exec net/sched/act_api.c:1049 [inline]
 tcf_action_exec+0x1a6/0x530 net/sched/act_api.c:1026
 tcf_exts_exec include/net/pkt_cls.h:326 [inline]
 route4_classify+0xef0/0x1400 net/sched/cls_route.c:179
 __tcf_classify net/sched/cls_api.c:1549 [inline]
 tcf_classify+0x3e8/0x9d0 net/sched/cls_api.c:1615
 prio_classify net/sched/sch_prio.c:42 [inline]
 prio_enqueue+0x3a7/0x790 net/sched/sch_prio.c:75
 dev_qdisc_enqueue+0x40/0x300 net/core/dev.c:3668
 __dev_xmit_skb net/core/dev.c:3756 [inline]
 __dev_queue_xmit+0x1f61/0x3660 net/core/dev.c:4081
 neigh_hh_output include/net/neighbour.h:533 [inline]
 neigh_output include/net/neighbour.h:547 [inline]
 ip_finish_output2+0x14dc/0x2170 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:306 [inline]
 __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:288
 ip_finish_output+0x32/0x200 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip_output+0x196/0x310 net/ipv4/ip_output.c:430
 dst_output include/net/dst.h:451 [inline]
 ip_local_out+0xaf/0x1a0 net/ipv4/ip_output.c:126
 iptunnel_xmit+0x628/0xa50 net/ipv4/ip_tunnel_core.c:82
 geneve_xmit_skb drivers/net/geneve.c:966 [inline]
 geneve_xmit+0x10c8/0x3530 drivers/net/geneve.c:1077
 __netdev_start_xmit include/linux/netdevice.h:4683 [inline]
 netdev_start_xmit include/linux/netdevice.h:4697 [inline]
 xmit_one net/core/dev.c:3473 [inline]
 dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3489
 __dev_queue_xmit+0x2985/0x3660 net/core/dev.c:4116
 neigh_hh_output include/net/neighbour.h:533 [inline]
 neigh_output include/net/neighbour.h:547 [inline]
 ip6_finish_output2+0xf7a/0x14f0 net/ipv6/ip6_output.c:126
 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline]
 __ip6_finish_output+0x61e/0xe90 net/ipv6/ip6_output.c:170
 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224
 dst_output include/net/dst.h:451 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 mld_sendpack+0x9a3/0xe40 net/ipv6/mcast.c:1826
 mld_send_cr net/ipv6/mcast.c:2127 [inline]
 mld_ifc_work+0x71c/0xdc0 net/ipv6/mcast.c:2659
 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307
 worker_thread+0x657/0x1110 kernel/workqueue.c:2454
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 &lt;/TASK&gt;
----------------
Code disassembly (best guess):
   0:   48 89 eb                mov    %rbp,%rbx
   3:   c6 45 01 01             movb   $0x1,0x1(%rbp)
   7:   41 bc 00 80 00 00       mov    $0x8000,%r12d
   d:   48 c1 e9 03             shr    $0x3,%rcx
  11:   83 e3 07                and    $0x7,%ebx
  14:   41 be 01 00 00 00       mov    $0x1,%r14d
  1a:   48 b8 00 00 00 00 00    movabs $0xdffffc0000000000,%rax
  21:   fc ff df
  24:   4c 8d 2c 01             lea    (%rcx,%rax,1),%r13
  28:   eb 0c                   jmp    0x36
* 2a:   f3 90                   pause &lt;-- trapping instruction
  2c:   41 83 ec 01             sub    $0x1,%r12d
  30:   0f 84 72 04 00 00       je     0x4a8
  36:   41 0f b6 45 00          movzbl 0x0(%r13),%eax
  3b:   38 d8                   cmp    %bl,%al
  3d:   7f 08                   jg     0x47
  3f:   84                      .byte 0x84

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Acked-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Cc: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Cc: Jiri Pirko &lt;jiri@resnulli.us&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Link: https://lore.kernel.org/r/20220215235305.3272331-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>net_sched: add __rcu annotation to netdev-&gt;qdisc</title>
<updated>2022-02-23T11:05:57Z</updated>
<author>
<name>Eric Dumazet</name>
</author>
<published>2022-02-11T20:06:23Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=18b57afacdc8dc1fa0d1a3c3a15a1d5a599159fa'/>
<id>urn:sha1:18b57afacdc8dc1fa0d1a3c3a15a1d5a599159fa</id>
<content type='text'>
commit 5891cd5ec46c2c2eb6427cb54d214b149635dd0e upstream.

syzbot found a data-race [1] which lead me to add __rcu
annotations to netdev-&gt;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 -&gt; 0xffff88815d96ec00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13560 Comm: syz-executor.2 Not tainted 5.17.0-rc3-syzkaller-00116-gf1baf68e1383-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 470502de5bdb ("net: sched: unlock rules update API")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Vlad Buslov &lt;vladbu@mellanox.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Cc: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Cc: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Cc: Jiri Pirko &lt;jiri@resnulli.us&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>net: sched: Clarify error message when qdisc kind is unknown</title>
<updated>2022-02-16T11:58:13Z</updated>
<author>
<name>Victor Nogueira</name>
</author>
<published>2022-01-18T17:19:09Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=5f155a692805d266e0af666f8e04f9b4f6781a58'/>
<id>urn:sha1:5f155a692805d266e0af666f8e04f9b4f6781a58</id>
<content type='text'>
[ Upstream commit 973bf8fdd12f0e70ea351c018e68edd377a836d1 ]

When adding a tc rule with a qdisc kind that is not supported or not
compiled into the kernel, the kernel emits the following error: "Error:
Specified qdisc not found.". Found via tdc testing when ETS qdisc was not
compiled in and it was not obvious right away what the message meant
without looking at the kernel code.

Change the error message to be more explicit and say the qdisc kind is
unknown.

Signed-off-by: Victor Nogueira &lt;victor@mojatatu.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>net: sched: fix use-after-free in tc_new_tfilter()</title>
<updated>2022-02-05T11:39:57Z</updated>
<author>
<name>Eric Dumazet</name>
</author>
<published>2022-01-31T17:20:18Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=95e34f61b58a152656cbe8d6e19843cc343fb089'/>
<id>urn:sha1:95e34f61b58a152656cbe8d6e19843cc343fb089</id>
<content type='text'>
commit 04c2a47ffb13c29778e2a14e414ad4cb5a5db4b5 upstream.

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-gff58831fa02d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 &lt;TASK&gt;
 __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 &lt;48&gt; 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
 &lt;/TASK&gt;

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
&gt;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: 470502de5bdb ("net: sched: unlock rules update API")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Vlad Buslov &lt;vladbu@mellanox.com&gt;
Cc: Jiri Pirko &lt;jiri@mellanox.com&gt;
Cc: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Link: https://lore.kernel.org/r/20220131172018.3704490-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>sch_htb: Fail on unsupported parameters when offload is requested</title>
<updated>2022-02-01T16:29:17Z</updated>
<author>
<name>Maxim Mikityanskiy</name>
</author>
<published>2022-01-25T10:06:54Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=42986f43685a9ca19b5cbed0d0a4ee591cf08f75'/>
<id>urn:sha1:42986f43685a9ca19b5cbed0d0a4ee591cf08f75</id>
<content type='text'>
[ Upstream commit 429c3be8a5e2695b5b92a6a12361eb89eb185495 ]

The current implementation of HTB offload doesn't support some
parameters. Instead of ignoring them, actively return the EINVAL error
when they are set to non-defaults.

As this patch goes to stable, the driver API is not changed here. If
future drivers support more offload parameters, the checks can be moved
to the driver side.

Note that the buffer and cbuffer parameters are also not supported, but
the tc userspace tool assigns some default values derived from rate and
ceil, and identifying these defaults in sch_htb would be unreliable, so
they are still ignored.

Fixes: d03b195b5aa0 ("sch_htb: Hierarchical QoS hardware offload")
Reported-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Maxim Mikityanskiy &lt;maximmi@nvidia.com&gt;
Reviewed-by: Tariq Toukan &lt;tariqt@nvidia.com&gt;
Link: https://lore.kernel.org/r/20220125100654.424570-1-maximmi@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>sch_api: Don't skip qdisc attach on ingress</title>
<updated>2022-01-27T11:03:03Z</updated>
<author>
<name>Maxim Mikityanskiy</name>
</author>
<published>2022-01-12T10:28:05Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=a2803127401d5f33cd7c999be9f4540443441d4b'/>
<id>urn:sha1:a2803127401d5f33cd7c999be9f4540443441d4b</id>
<content type='text'>
commit de2d807b294d3d2ce5e59043ae2634016765d076 upstream.

The attach callback of struct Qdisc_ops is used by only a few qdiscs:
mq, mqprio and htb. qdisc_graft() contains the following logic
(pseudocode):

    if (!qdisc-&gt;ops-&gt;attach) {
        if (ingress)
            do ingress stuff;
        else
            do egress stuff;
    }
    if (!ingress) {
        ...
        if (qdisc-&gt;ops-&gt;attach)
            qdisc-&gt;ops-&gt;attach(qdisc);
    } else {
        ...
    }

As we see, the attach callback is not called if the qdisc is being
attached to ingress (TC_H_INGRESS). That wasn't a problem for mq and
mqprio, since they contain a check that they are attached to TC_H_ROOT,
and they can't be attached to TC_H_INGRESS anyway.

However, the commit cited below added the attach callback to htb. It is
needed for the hardware offload, but in the non-offload mode it
simulates the "do egress stuff" part of the pseudocode above. The
problem is that when htb is attached to ingress, neither "do ingress
stuff" nor attach() is called. It results in an inconsistency, and the
following message is printed to dmesg:

unregister_netdevice: waiting for lo to become free. Usage count = 2

This commit addresses the issue by running "do ingress stuff" in the
ingress flow even in the attach callback is present, which is fine,
because attach isn't going to be called afterwards.

The bug was found by syzbot and reported by Eric.

Fixes: d03b195b5aa0 ("sch_htb: Hierarchical QoS hardware offload")
Signed-off-by: Maxim Mikityanskiy &lt;maximmi@nvidia.com&gt;
Reported-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>net_sched: restore "mpu xxx" handling</title>
<updated>2022-01-27T11:03:01Z</updated>
<author>
<name>Kevin Bracey</name>
</author>
<published>2022-01-12T17:02:10Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=acac3b44c43570b03ee2ea212e6bb093e4dd3f27'/>
<id>urn:sha1:acac3b44c43570b03ee2ea212e6bb093e4dd3f27</id>
<content type='text'>
commit fb80445c438c78b40b547d12b8d56596ce4ccfeb upstream.

commit 56b765b79e9a ("htb: improved accuracy at high rates") broke
"overhead X", "linklayer atm" and "mpu X" attributes.

"overhead X" and "linklayer atm" have already been fixed. This restores
the "mpu X" handling, as might be used by DOCSIS or Ethernet shaping:

    tc class add ... htb rate X overhead 4 mpu 64

The code being fixed is used by htb, tbf and act_police. Cake has its
own mpu handling. qdisc_calculate_pkt_len still uses the size table
containing values adjusted for mpu by user space.

iproute2 tc has always passed mpu into the kernel via a tc_ratespec
structure, but the kernel never directly acted on it, merely stored it
so that it could be read back by `tc class show`.

Rather, tc would generate length-to-time tables that included the mpu
(and linklayer) in their construction, and the kernel used those tables.

Since v3.7, the tables were no longer used. Along with "mpu", this also
broke "overhead" and "linklayer" which were fixed in 01cb71d2d47b
("net_sched: restore "overhead xxx" handling", v3.10) and 8a8e3d84b171
("net_sched: restore "linklayer atm" handling", v3.11).

"overhead" was fixed by simply restoring use of tc_ratespec::overhead -
this had originally been used by the kernel but was initially omitted
from the new non-table-based calculations.

"linklayer" had been handled in the table like "mpu", but the mode was
not originally passed in tc_ratespec. The new implementation was made to
handle it by getting new versions of tc to pass the mode in an extended
tc_ratespec, and for older versions of tc the table contents were analysed
at load time to deduce linklayer.

As "mpu" has always been given to the kernel in tc_ratespec,
accompanying the mpu-based table, we can restore system functionality
with no userspace change by making the kernel act on the tc_ratespec
value.

Fixes: 56b765b79e9a ("htb: improved accuracy at high rates")
Signed-off-by: Kevin Bracey &lt;kevin@bracey.fi&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Jiri Pirko &lt;jiri@resnulli.us&gt;
Cc: Vimalkumar &lt;j.vimal@gmail.com&gt;
Link: https://lore.kernel.org/r/20220112170210.1014351-1-kevin@bracey.fi
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
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