linux-stable.git/net/sched, branch v6.2

net/sched: tcindex: search key must be 16 bits

2023-02-15T10:23:54+00:00

Syzkaller found an issue where a handle greater than 16 bits would trigger
a null-ptr-deref in the imperfect hash area update.

general protection fault, probably for non-canonical address
0xdffffc0000000015: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af]
CPU: 0 PID: 5070 Comm: syz-executor456 Not tainted
6.2.0-rc7-syzkaller-00112-gc68f345b7c42 #0
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 01/21/2023
RIP: 0010:tcindex_set_parms+0x1a6a/0x2990 net/sched/cls_tcindex.c:509
Code: 01 e9 e9 fe ff ff 4c 8b bd 28 fe ff ff e8 0e 57 7d f9 48 8d bb
a8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c
02 00 0f 85 94 0c 00 00 48 8b 85 f8 fd ff ff 48 8b 9b a8 00
RSP: 0018:ffffc90003d3ef88 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000015 RSI: ffffffff8803a102 RDI: 00000000000000a8
RBP: ffffc90003d3f1d8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801e2b10a8
R13: dffffc0000000000 R14: 0000000000030000 R15: ffff888017b3be00
FS: 00005555569af300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056041c6d2000 CR3: 000000002bfca000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:

tcindex_change+0x1ea/0x320 net/sched/cls_tcindex.c:572
tc_new_tfilter+0x96e/0x2220 net/sched/cls_api.c:2155
rtnetlink_rcv_msg+0x959/0xca0 net/core/rtnetlink.c:6132
netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2574
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1942
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xd3/0x120 net/socket.c:734
____sys_sendmsg+0x334/0x8c0 net/socket.c:2476
___sys_sendmsg+0x110/0x1b0 net/socket.c:2530
__sys_sendmmsg+0x18f/0x460 net/socket.c:2616
__do_sys_sendmmsg net/socket.c:2645 [inline]
__se_sys_sendmmsg net/socket.c:2642 [inline]
__x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2642
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80

Fixes: ee059170b1f7 ("net/sched: tcindex: update imperfect hash filters respecting rcu")
Signed-off-by: Jamal Hadi Salim 
Signed-off-by: Pedro Tammela 
Reported-by: syzbot 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

net/sched: act_ctinfo: use percpu stats

2023-02-14T04:09:01+00:00

The tc action act_ctinfo was using shared stats, fix it to use percpu stats
since bstats_update() must be called with locks or with a percpu pointer argument.

tdc results:
1..12
ok 1 c826 - Add ctinfo action with default setting
ok 2 0286 - Add ctinfo action with dscp
ok 3 4938 - Add ctinfo action with valid cpmark and zone
ok 4 7593 - Add ctinfo action with drop control
ok 5 2961 - Replace ctinfo action zone and action control
ok 6 e567 - Delete ctinfo action with valid index
ok 7 6a91 - Delete ctinfo action with invalid index
ok 8 5232 - List ctinfo actions
ok 9 7702 - Flush ctinfo actions
ok 10 3201 - Add ctinfo action with duplicate index
ok 11 8295 - Add ctinfo action with invalid index
ok 12 3964 - Replace ctinfo action with invalid goto_chain control

Fixes: 24ec483cec98 ("net: sched: Introduce act_ctinfo action")
Reviewed-by: Jamal Hadi Salim 
Signed-off-by: Pedro Tammela 
Reviewed-by: Larysa Zaremba 
Link: https://lore.kernel.org/r/20230210200824.444856-1-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski

net/sched: tcindex: update imperfect hash filters respecting rcu

2023-02-11T03:38:27+00:00

The imperfect hash area can be updated while packets are traversing,
which will cause a use-after-free when 'tcf_exts_exec()' is called
with the destroyed tcf_ext.

CPU 0:               CPU 1:
tcindex_set_parms    tcindex_classify
tcindex_lookup
                     tcindex_lookup
tcf_exts_change
                     tcf_exts_exec [UAF]

Stop operating on the shared area directly, by using a local copy,
and update the filter with 'rcu_replace_pointer()'. Delete the old
filter version only after a rcu grace period elapsed.

Fixes: 9b0d4446b569 ("net: sched: avoid atomic swap in tcf_exts_change")
Reported-by: valis 
Suggested-by: valis 
Signed-off-by: Jamal Hadi Salim 
Signed-off-by: Pedro Tammela 
Link: https://lore.kernel.org/r/20230209143739.279867-1-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski

net: sched: sch: Fix off by one in htb_activate_prios()

2023-02-08T07:38:53+00:00

The > needs be >= to prevent an out of bounds access.

Fixes: de5ca4c3852f ("net: sched: sch: Bounds check priority")
Signed-off-by: Dan Carpenter 
Reviewed-by: Simon Horman 
Reviewed-by: Kees Cook 
Link: https://lore.kernel.org/r/Y+D+KN18FQI2DKLq@kili
Signed-off-by: Jakub Kicinski

net: sched: sch: Bounds check priority

2023-01-31T09:37:58+00:00

Nothing was explicitly bounds checking the priority index used to access
clpriop[]. WARN and bail out early if it's pathological. Seen with GCC 13:

../net/sched/sch_htb.c: In function 'htb_activate_prios':
../net/sched/sch_htb.c:437:44: warning: array subscript [0, 31] is outside array bounds of 'struct htb_prio[8]' [-Warray-bounds=]
  437 |                         if (p->inner.clprio[prio].feed.rb_node)
      |                             ~~~~~~~~~~~~~~~^~~~~~
../net/sched/sch_htb.c:131:41: note: while referencing 'clprio'
  131 |                         struct htb_prio clprio[TC_HTB_NUMPRIO];
      |                                         ^~~~~~

Cc: Jamal Hadi Salim 
Cc: Cong Wang 
Cc: Jiri Pirko 
Cc: "David S. Miller" 
Cc: Eric Dumazet 
Cc: Jakub Kicinski 
Cc: Paolo Abeni 
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook 
Reviewed-by: Simon Horman 
Reviewed-by: Cong Wang 
Link: https://lore.kernel.org/r/20230127224036.never.561-kees@kernel.org
Signed-off-by: Paolo Abeni

net/sched: sch_taprio: do not schedule in taprio_reset()

2023-01-25T02:17:29+00:00

As reported by syzbot and hinted by Vinicius, I should not have added
a qdisc_synchronize() call in taprio_reset()

taprio_reset() can be called with qdisc spinlock held (and BH disabled)
as shown in included syzbot report [1].

Only taprio_destroy() needed this synchronization, as explained
in the blamed commit changelog.

[1]

BUG: scheduling while atomic: syz-executor150/5091/0x00000202
2 locks held by syz-executor150/5091:
Modules linked in:
Preemption disabled at:
[<0000000000000000>] 0x0
Kernel panic - not syncing: scheduling while atomic: panic_on_warn set ...
CPU: 1 PID: 5091 Comm: syz-executor150 Not tainted 6.2.0-rc3-syzkaller-00219-g010a74f52203 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Call Trace:

__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
panic+0x2cc/0x626 kernel/panic.c:318
check_panic_on_warn.cold+0x19/0x35 kernel/panic.c:238
__schedule_bug.cold+0xd5/0xfe kernel/sched/core.c:5836
schedule_debug kernel/sched/core.c:5865 [inline]
__schedule+0x34e4/0x5450 kernel/sched/core.c:6500
schedule+0xde/0x1b0 kernel/sched/core.c:6682
schedule_timeout+0x14e/0x2a0 kernel/time/timer.c:2167
schedule_timeout_uninterruptible kernel/time/timer.c:2201 [inline]
msleep+0xb6/0x100 kernel/time/timer.c:2322
qdisc_synchronize include/net/sch_generic.h:1295 [inline]
taprio_reset+0x93/0x270 net/sched/sch_taprio.c:1703
qdisc_reset+0x10c/0x770 net/sched/sch_generic.c:1022
dev_reset_queue+0x92/0x130 net/sched/sch_generic.c:1285
netdev_for_each_tx_queue include/linux/netdevice.h:2464 [inline]
dev_deactivate_many+0x36d/0x9f0 net/sched/sch_generic.c:1351
dev_deactivate+0xed/0x1b0 net/sched/sch_generic.c:1374
qdisc_graft+0xe4a/0x1380 net/sched/sch_api.c:1080
tc_modify_qdisc+0xb6b/0x19a0 net/sched/sch_api.c:1689
rtnetlink_rcv_msg+0x43e/0xca0 net/core/rtnetlink.c:6141
netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2564
netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1356
netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1932
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xd3/0x120 net/socket.c:734
____sys_sendmsg+0x712/0x8c0 net/socket.c:2476
___sys_sendmsg+0x110/0x1b0 net/socket.c:2530
__sys_sendmsg+0xf7/0x1c0 net/socket.c:2559
do_syscall_x64 arch/x86/entry/common.c:50 [inline]

Fixes: 3a415d59c1db ("net/sched: sch_taprio: fix possible use-after-free")
Link: https://lore.kernel.org/netdev/167387581653.2747.13878941339893288655.git-patchwork-notify@kernel.org/T/
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Cc: Vinicius Costa Gomes 
Link: https://lore.kernel.org/r/20230123084552.574396-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: sched: gred: prevent races when adding offloads to stats

2023-01-19T04:28:25+00:00

Naresh reports seeing a warning that gred is calling
u64_stats_update_begin() with preemption enabled.
Arnd points out it's coming from _bstats_update().

We should be holding the qdisc lock when writing
to stats, they are also updated from the datapath.

Reported-by: Linux Kernel Functional Testing 
Link: https://lore.kernel.org/all/CA+G9fYsTr9_r893+62u6UGD3dVaCE-kN9C-Apmb2m=hxjc1Cqg@mail.gmail.com/
Fixes: e49efd5288bd ("net: sched: gred: support reporting stats from offloads")
Link: https://lore.kernel.org/r/20230113044137.1383067-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski

net/sched: sch_taprio: fix possible use-after-free

2023-01-16T13:25:34+00:00

syzbot reported a nasty crash [1] in net_tx_action() which
made little sense until we got a repro.

This repro installs a taprio qdisc, but providing an
invalid TCA_RATE attribute.

qdisc_create() has to destroy the just initialized
taprio qdisc, and taprio_destroy() is called.

However, the hrtimer used by taprio had already fired,
therefore advance_sched() called __netif_schedule().

Then net_tx_action was trying to use a destroyed qdisc.

We can not undo the __netif_schedule(), so we must wait
until one cpu serviced the qdisc before we can proceed.

Many thanks to Alexander Potapenko for his help.

[1]
BUG: KMSAN: uninit-value in queued_spin_trylock include/asm-generic/qspinlock.h:94 [inline]
BUG: KMSAN: uninit-value in do_raw_spin_trylock include/linux/spinlock.h:191 [inline]
BUG: KMSAN: uninit-value in __raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
BUG: KMSAN: uninit-value in _raw_spin_trylock+0x92/0xa0 kernel/locking/spinlock.c:138
 queued_spin_trylock include/asm-generic/qspinlock.h:94 [inline]
 do_raw_spin_trylock include/linux/spinlock.h:191 [inline]
 __raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
 _raw_spin_trylock+0x92/0xa0 kernel/locking/spinlock.c:138
 spin_trylock include/linux/spinlock.h:359 [inline]
 qdisc_run_begin include/net/sch_generic.h:187 [inline]
 qdisc_run+0xee/0x540 include/net/pkt_sched.h:125
 net_tx_action+0x77c/0x9a0 net/core/dev.c:5086
 __do_softirq+0x1cc/0x7fb kernel/softirq.c:571
 run_ksoftirqd+0x2c/0x50 kernel/softirq.c:934
 smpboot_thread_fn+0x554/0x9f0 kernel/smpboot.c:164
 kthread+0x31b/0x430 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:732 [inline]
 slab_alloc_node mm/slub.c:3258 [inline]
 __kmalloc_node_track_caller+0x814/0x1250 mm/slub.c:4970
 kmalloc_reserve net/core/skbuff.c:358 [inline]
 __alloc_skb+0x346/0xcf0 net/core/skbuff.c:430
 alloc_skb include/linux/skbuff.h:1257 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 netlink_ack+0x5f3/0x12b0 net/netlink/af_netlink.c:2436
 netlink_rcv_skb+0x55d/0x6c0 net/netlink/af_netlink.c:2507
 rtnetlink_rcv+0x30/0x40 net/core/rtnetlink.c:6108
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0xf3b/0x1270 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x1288/0x1440 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 ____sys_sendmsg+0xabc/0xe90 net/socket.c:2482
 ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2536
 __sys_sendmsg net/socket.c:2565 [inline]
 __do_sys_sendmsg net/socket.c:2574 [inline]
 __se_sys_sendmsg net/socket.c:2572 [inline]
 __x64_sys_sendmsg+0x367/0x540 net/socket.c:2572
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

CPU: 0 PID: 13 Comm: ksoftirqd/0 Not tainted 6.0.0-rc2-syzkaller-47461-gac3859c02d7f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022

Fixes: 5a781ccbd19e ("tc: Add support for configuring the taprio scheduler")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Cc: Alexander Potapenko 
Cc: Vinicius Costa Gomes 
Signed-off-by: David S. Miller

sch_htb: Avoid grafting on htb_destroy_class_offload when destroying htb

2023-01-14T06:14:25+00:00

Peek at old qdisc and graft only when deleting a leaf class in the htb,
rather than when deleting the htb itself. Do not peek at the qdisc of the
netdev queue when destroying the htb. The caller may already have grafted a
new qdisc that is not part of the htb structure being destroyed.

This fix resolves two use cases.

  1. Using tc to destroy the htb.
    - Netdev was being prematurely activated before the htb was fully
      destroyed.
  2. Using tc to replace the htb with another qdisc (which also leads to
     the htb being destroyed).
    - Premature netdev activation like previous case. Newly grafted qdisc
      was also getting accidentally overwritten when destroying the htb.

Fixes: d03b195b5aa0 ("sch_htb: Hierarchical QoS hardware offload")
Signed-off-by: Rahul Rameshbabu 
Reviewed-by: Saeed Mahameed 
Reviewed-by: Maxim Mikityanskiy 
Reviewed-by: Jiri Pirko 
Link: https://lore.kernel.org/r/20230113005528.302625-1-rrameshbabu@nvidia.com
Signed-off-by: Jakub Kicinski

net: sched: disallow noqueue for qdisc classes

2023-01-11T02:19:32+00:00

While experimenting with applying noqueue to a classful queue discipline,
we discovered a NULL pointer dereference in the __dev_queue_xmit()
path that generates a kernel OOPS:

    # dev=enp0s5
    # tc qdisc replace dev $dev root handle 1: htb default 1
    # tc class add dev $dev parent 1: classid 1:1 htb rate 10mbit
    # tc qdisc add dev $dev parent 1:1 handle 10: noqueue
    # ping -I $dev -w 1 -c 1 1.1.1.1

[    2.172856] BUG: kernel NULL pointer dereference, address: 0000000000000000
[    2.173217] #PF: supervisor instruction fetch in kernel mode
...
[    2.178451] Call Trace:
[    2.178577]  
[    2.178686]  htb_enqueue+0x1c8/0x370
[    2.178880]  dev_qdisc_enqueue+0x15/0x90
[    2.179093]  __dev_queue_xmit+0x798/0xd00
[    2.179305]  ? _raw_write_lock_bh+0xe/0x30
[    2.179522]  ? __local_bh_enable_ip+0x32/0x70
[    2.179759]  ? ___neigh_create+0x610/0x840
[    2.179968]  ? eth_header+0x21/0xc0
[    2.180144]  ip_finish_output2+0x15e/0x4f0
[    2.180348]  ? dst_output+0x30/0x30
[    2.180525]  ip_push_pending_frames+0x9d/0xb0
[    2.180739]  raw_sendmsg+0x601/0xcb0
[    2.180916]  ? _raw_spin_trylock+0xe/0x50
[    2.181112]  ? _raw_spin_unlock_irqrestore+0x16/0x30
[    2.181354]  ? get_page_from_freelist+0xcd6/0xdf0
[    2.181594]  ? sock_sendmsg+0x56/0x60
[    2.181781]  sock_sendmsg+0x56/0x60
[    2.181958]  __sys_sendto+0xf7/0x160
[    2.182139]  ? handle_mm_fault+0x6e/0x1d0
[    2.182366]  ? do_user_addr_fault+0x1e1/0x660
[    2.182627]  __x64_sys_sendto+0x1b/0x30
[    2.182881]  do_syscall_64+0x38/0x90
[    2.183085]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
...
[    2.187402]  

Previously in commit d66d6c3152e8 ("net: sched: register noqueue
qdisc"), NULL was set for the noqueue discipline on noqueue init
so that __dev_queue_xmit() falls through for the noqueue case. This
also sets a bypass of the enqueue NULL check in the
register_qdisc() function for the struct noqueue_disc_ops.

Classful queue disciplines make it past the NULL check in
__dev_queue_xmit() because the discipline is set to htb (in this case),
and then in the call to __dev_xmit_skb(), it calls into htb_enqueue()
which grabs a leaf node for a class and then calls qdisc_enqueue() by
passing in a queue discipline which assumes ->enqueue() is not set to NULL.

Fix this by not allowing classes to be assigned to the noqueue
discipline. Linux TC Notes states that classes cannot be set to
the noqueue discipline. [1] Let's enforce that here.

Links:
1. https://linux-tc-notes.sourceforge.net/tc/doc/sch_noqueue.txt

Fixes: d66d6c3152e8 ("net: sched: register noqueue qdisc")
Cc: stable@vger.kernel.org
Signed-off-by: Frederick Lawler 
Reviewed-by: Jakub Sitnicki 
Link: https://lore.kernel.org/r/20230109163906.706000-1-fred@cloudflare.com
Signed-off-by: Jakub Kicinski