Commit Graph

3905 Commits

Author SHA1 Message Date
Eric Dumazet
3cb7cf1540 net/sched: accept TCA_STAB only for root qdisc
Most qdiscs maintain their backlog using qdisc_pkt_len(skb)
on the assumption it is invariant between the enqueue()
and dequeue() handlers.

Unfortunately syzbot can crash a host rather easily using
a TBF + SFQ combination, with an STAB on SFQ [1]

We can't support TCA_STAB on arbitrary level, this would
require to maintain per-qdisc storage.

[1]
[   88.796496] BUG: kernel NULL pointer dereference, address: 0000000000000000
[   88.798611] #PF: supervisor read access in kernel mode
[   88.799014] #PF: error_code(0x0000) - not-present page
[   88.799506] PGD 0 P4D 0
[   88.799829] Oops: Oops: 0000 [#1] SMP NOPTI
[   88.800569] CPU: 14 UID: 0 PID: 2053 Comm: b371744477 Not tainted 6.12.0-rc1-virtme #1117
[   88.801107] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   88.801779] RIP: 0010:sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq
[ 88.802544] Code: 0f b7 50 12 48 8d 04 d5 00 00 00 00 48 89 d6 48 29 d0 48 8b 91 c0 01 00 00 48 c1 e0 03 48 01 c2 66 83 7a 1a 00 7e c0 48 8b 3a <4c> 8b 07 4c 89 02 49 89 50 08 48 c7 47 08 00 00 00 00 48 c7 07 00
All code
========
   0:	0f b7 50 12          	movzwl 0x12(%rax),%edx
   4:	48 8d 04 d5 00 00 00 	lea    0x0(,%rdx,8),%rax
   b:	00
   c:	48 89 d6             	mov    %rdx,%rsi
   f:	48 29 d0             	sub    %rdx,%rax
  12:	48 8b 91 c0 01 00 00 	mov    0x1c0(%rcx),%rdx
  19:	48 c1 e0 03          	shl    $0x3,%rax
  1d:	48 01 c2             	add    %rax,%rdx
  20:	66 83 7a 1a 00       	cmpw   $0x0,0x1a(%rdx)
  25:	7e c0                	jle    0xffffffffffffffe7
  27:	48 8b 3a             	mov    (%rdx),%rdi
  2a:*	4c 8b 07             	mov    (%rdi),%r8		<-- trapping instruction
  2d:	4c 89 02             	mov    %r8,(%rdx)
  30:	49 89 50 08          	mov    %rdx,0x8(%r8)
  34:	48 c7 47 08 00 00 00 	movq   $0x0,0x8(%rdi)
  3b:	00
  3c:	48                   	rex.W
  3d:	c7                   	.byte 0xc7
  3e:	07                   	(bad)
	...

Code starting with the faulting instruction
===========================================
   0:	4c 8b 07             	mov    (%rdi),%r8
   3:	4c 89 02             	mov    %r8,(%rdx)
   6:	49 89 50 08          	mov    %rdx,0x8(%r8)
   a:	48 c7 47 08 00 00 00 	movq   $0x0,0x8(%rdi)
  11:	00
  12:	48                   	rex.W
  13:	c7                   	.byte 0xc7
  14:	07                   	(bad)
	...
[   88.803721] RSP: 0018:ffff9a1f892b7d58 EFLAGS: 00000206
[   88.804032] RAX: 0000000000000000 RBX: ffff9a1f8420c800 RCX: ffff9a1f8420c800
[   88.804560] RDX: ffff9a1f81bc1440 RSI: 0000000000000000 RDI: 0000000000000000
[   88.805056] RBP: ffffffffc04bb0e0 R08: 0000000000000001 R09: 00000000ff7f9a1f
[   88.805473] R10: 000000000001001b R11: 0000000000009a1f R12: 0000000000000140
[   88.806194] R13: 0000000000000001 R14: ffff9a1f886df400 R15: ffff9a1f886df4ac
[   88.806734] FS:  00007f445601a740(0000) GS:ffff9a2e7fd80000(0000) knlGS:0000000000000000
[   88.807225] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   88.807672] CR2: 0000000000000000 CR3: 000000050cc46000 CR4: 00000000000006f0
[   88.808165] Call Trace:
[   88.808459]  <TASK>
[   88.808710] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434)
[   88.809261] ? page_fault_oops (arch/x86/mm/fault.c:715)
[   88.809561] ? exc_page_fault (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:87 ./arch/x86/include/asm/irqflags.h:147 arch/x86/mm/fault.c:1489 arch/x86/mm/fault.c:1539)
[   88.809806] ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:623)
[   88.810074] ? sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq
[   88.810411] sfq_reset (net/sched/sch_sfq.c:525) sch_sfq
[   88.810671] qdisc_reset (./include/linux/skbuff.h:2135 ./include/linux/skbuff.h:2441 ./include/linux/skbuff.h:3304 ./include/linux/skbuff.h:3310 net/sched/sch_generic.c:1036)
[   88.810950] tbf_reset (./include/linux/timekeeping.h:169 net/sched/sch_tbf.c:334) sch_tbf
[   88.811208] qdisc_reset (./include/linux/skbuff.h:2135 ./include/linux/skbuff.h:2441 ./include/linux/skbuff.h:3304 ./include/linux/skbuff.h:3310 net/sched/sch_generic.c:1036)
[   88.811484] netif_set_real_num_tx_queues (./include/linux/spinlock.h:396 ./include/net/sch_generic.h:768 net/core/dev.c:2958)
[   88.811870] __tun_detach (drivers/net/tun.c:590 drivers/net/tun.c:673)
[   88.812271] tun_chr_close (drivers/net/tun.c:702 drivers/net/tun.c:3517)
[   88.812505] __fput (fs/file_table.c:432 (discriminator 1))
[   88.812735] task_work_run (kernel/task_work.c:230)
[   88.813016] do_exit (kernel/exit.c:940)
[   88.813372] ? trace_hardirqs_on (kernel/trace/trace_preemptirq.c:58 (discriminator 4))
[   88.813639] ? handle_mm_fault (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:97 ./arch/x86/include/asm/irqflags.h:155 ./include/linux/memcontrol.h:1022 ./include/linux/memcontrol.h:1045 ./include/linux/memcontrol.h:1052 mm/memory.c:5928 mm/memory.c:6088)
[   88.813867] do_group_exit (kernel/exit.c:1070)
[   88.814138] __x64_sys_exit_group (kernel/exit.c:1099)
[   88.814490] x64_sys_call (??:?)
[   88.814791] do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1))
[   88.815012] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   88.815495] RIP: 0033:0x7f44560f1975

Fixes: 175f9c1bba ("net_sched: Add size table for qdiscs")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Link: https://patch.msgid.link/20241007184130.3960565-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-08 15:38:56 -07:00
Al Viro
5f60d5f6bb move asm/unaligned.h to linux/unaligned.h
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
2024-10-02 17:23:23 -04:00
Dave Taht
c48994baef sch_cake: constify inverse square root cache
sch_cake uses a cache of the first 16 values of the inverse square root
calculation for the Cobalt AQM to save some cycles on the fast path.
This cache is populated when the qdisc is first loaded, but there's
really no reason why it can't just be pre-populated. So change it to be
pre-populated with constants, which also makes it possible to constify
it.

This gives a modest space saving for the module (not counting debug data):
.text:  -224 bytes
.rodata: +80 bytes
.bss:    -64 bytes
Total:  -192 bytes

Signed-off-by: Dave Taht <dave.taht@gmail.com>
[ fixed up comment, rewrote commit message ]
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20240909091630.22177-1-toke@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 18:31:52 -07:00
Dmitry Antipov
d5c4546062 net: sched: consistently use rcu_replace_pointer() in taprio_change()
According to Vinicius (and carefully looking through the whole
https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa
once again), txtime branch of 'taprio_change()' is not going to
race against 'advance_sched()'. But using 'rcu_replace_pointer()'
in the former may be a good idea as well.

Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-09-08 11:18:57 +01:00
Jakub Kicinski
502cc061de Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/phy/phy_device.c
  2560db6ede ("net: phy: Fix missing of_node_put() for leds")
  1dce520abd ("net: phy: Use for_each_available_child_of_node_scoped()")
https://lore.kernel.org/20240904115823.74333648@canb.auug.org.au

Adjacent changes:

drivers/net/ethernet/xilinx/xilinx_axienet.h
drivers/net/ethernet/xilinx/xilinx_axienet_main.c
  858430db28 ("net: xilinx: axienet: Fix race in axienet_stop")
  76abb5d675 ("net: xilinx: axienet: Add statistics support")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-05 20:37:20 -07:00
Toke Høiland-Jørgensen
546ea84d07 sched: sch_cake: fix bulk flow accounting logic for host fairness
In sch_cake, we keep track of the count of active bulk flows per host,
when running in dst/src host fairness mode, which is used as the
round-robin weight when iterating through flows. The count of active
bulk flows is updated whenever a flow changes state.

This has a peculiar interaction with the hash collision handling: when a
hash collision occurs (after the set-associative hashing), the state of
the hash bucket is simply updated to match the new packet that collided,
and if host fairness is enabled, that also means assigning new per-host
state to the flow. For this reason, the bulk flow counters of the
host(s) assigned to the flow are decremented, before new state is
assigned (and the counters, which may not belong to the same host
anymore, are incremented again).

Back when this code was introduced, the host fairness mode was always
enabled, so the decrement was unconditional. When the configuration
flags were introduced the *increment* was made conditional, but
the *decrement* was not. Which of course can lead to a spurious
decrement (and associated wrap-around to U16_MAX).

AFAICT, when host fairness is disabled, the decrement and wrap-around
happens as soon as a hash collision occurs (which is not that common in
itself, due to the set-associative hashing). However, in most cases this
is harmless, as the value is only used when host fairness mode is
enabled. So in order to trigger an array overflow, sch_cake has to first
be configured with host fairness disabled, and while running in this
mode, a hash collision has to occur to cause the overflow. Then, the
qdisc has to be reconfigured to enable host fairness, which leads to the
array out-of-bounds because the wrapped-around value is retained and
used as an array index. It seems that syzbot managed to trigger this,
which is quite impressive in its own right.

This patch fixes the issue by introducing the same conditional check on
decrement as is used on increment.

The original bug predates the upstreaming of cake, but the commit listed
in the Fixes tag touched that code, meaning that this patch won't apply
before that.

Fixes: 7126399299 ("sch_cake: Make the dual modes fairer")
Reported-by: syzbot+7fe7b81d602cc1e6b94d@syzkaller.appspotmail.com
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20240903160846.20909-1-toke@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-09-05 11:49:57 +02:00
Stephen Hemminger
3b3a2a9c63 sch/netem: fix use after free in netem_dequeue
If netem_dequeue() enqueues packet to inner qdisc and that qdisc
returns __NET_XMIT_STOLEN. The packet is dropped but
qdisc_tree_reduce_backlog() is not called to update the parent's
q.qlen, leading to the similar use-after-free as Commit
e04991a48dbaf382 ("netem: fix return value if duplicate enqueue
fails")

Commands to trigger KASAN UaF:

ip link add type dummy
ip link set lo up
ip link set dummy0 up
tc qdisc add dev lo parent root handle 1: drr
tc filter add dev lo parent 1: basic classid 1:1
tc class add dev lo classid 1:1 drr
tc qdisc add dev lo parent 1:1 handle 2: netem
tc qdisc add dev lo parent 2: handle 3: drr
tc filter add dev lo parent 3: basic classid 3:1 action mirred egress
redirect dev dummy0
tc class add dev lo classid 3:1 drr
ping -c1 -W0.01 localhost # Trigger bug
tc class del dev lo classid 1:1
tc class add dev lo classid 1:1 drr
ping -c1 -W0.01 localhost # UaF

Fixes: 50612537e9 ("netem: fix classful handling")
Reported-by: Budimir Markovic <markovicbudimir@gmail.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://patch.msgid.link/20240901182438.4992-1-stephen@networkplumber.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-03 11:44:23 -07:00
Jakub Kicinski
3cbd2090d3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/ethernet/faraday/ftgmac100.c
  4186c8d9e6 ("net: ftgmac100: Ensure tx descriptor updates are visible")
  e24a6c8746 ("net: ftgmac100: Get link speed and duplex for NC-SI")
https://lore.kernel.org/0b851ec5-f91d-4dd3-99da-e81b98c9ed28@kernel.org

net/ipv4/tcp.c
  bac76cf898 ("tcp: fix forever orphan socket caused by tcp_abort")
  edefba66d9 ("tcp: rstreason: introduce SK_RST_REASON_TCP_STATE for active reset")
https://lore.kernel.org/20240828112207.5c199d41@canb.auug.org.au

No adjacent changes.

Link: https://patch.msgid.link/20240829130829.39148-1-pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-29 11:49:10 -07:00
Eric Dumazet
bc21000e99 net_sched: sch_fq: fix incorrect behavior for small weights
fq_dequeue() has a complex logic to find packets in one of the 3 bands.

As Neal found out, it is possible that one band has a deficit smaller
than its weight. fq_dequeue() can return NULL while some packets are
elligible for immediate transmit.

In this case, more than one iteration is needed to refill pband->credit.

With default parameters (weights 589824 196608 65536) bug can trigger
if large BIG TCP packets are sent to the lowest priority band.

Bisected-by: John Sperbeck <jsperbeck@google.com>
Diagnosed-by: Neal Cardwell <ncardwell@google.com>
Fixes: 29f834aa32 ("net_sched: sch_fq: add 3 bands and WRR scheduling")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Link: https://patch.msgid.link/20240824181901.953776-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-27 08:20:45 -07:00
Boris Sukholitko
9388637270 tc: adjust network header after 2nd vlan push
<tldr>
skb network header of the single-tagged vlan packet continues to point the
vlan payload (e.g. IP) after second vlan tag is pushed by tc act_vlan. This
causes problem at the dissector which expects double-tagged packet network
header to point to the inner vlan.

The fix is to adjust network header in tcf_act_vlan.c but requires
refactoring of skb_vlan_push function.
</tldr>

Consider the following shell script snippet configuring TC rules on the
veth interface:

ip link add veth0 type veth peer veth1
ip link set veth0 up
ip link set veth1 up

tc qdisc add dev veth0 clsact

tc filter add dev veth0 ingress pref 10 chain 0 flower \
	num_of_vlans 2 cvlan_ethtype 0x800 action goto chain 5
tc filter add dev veth0 ingress pref 20 chain 0 flower \
	num_of_vlans 1 action vlan push id 100 \
	protocol 0x8100 action goto chain 5
tc filter add dev veth0 ingress pref 30 chain 5 flower \
	num_of_vlans 2 cvlan_ethtype 0x800 action simple sdata "success"

Sending double-tagged vlan packet with the IP payload inside:

cat <<ENDS | text2pcap - - | tcpreplay -i veth1 -
0000  00 00 00 00 00 11 00 00 00 00 00 22 81 00 00 64   ..........."...d
0010  81 00 00 14 08 00 45 04 00 26 04 d2 00 00 7f 11   ......E..&......
0020  18 ef 0a 00 00 01 14 00 00 02 00 00 00 00 00 12   ................
0030  e1 c7 00 00 00 00 00 00 00 00 00 00               ............
ENDS

will match rule 10, goto rule 30 in chain 5 and correctly emit "success" to
the dmesg.

OTOH, sending single-tagged vlan packet:

cat <<ENDS | text2pcap - - | tcpreplay -i veth1 -
0000  00 00 00 00 00 11 00 00 00 00 00 22 81 00 00 14   ..........."....
0010  08 00 45 04 00 2a 04 d2 00 00 7f 11 18 eb 0a 00   ..E..*..........
0020  00 01 14 00 00 02 00 00 00 00 00 16 e1 bf 00 00   ................
0030  00 00 00 00 00 00 00 00 00 00 00 00               ............
ENDS

will match rule 20, will push the second vlan tag but will *not* match
rule 30. IOW, the match at rule 30 fails if the second vlan was freshly
pushed by the kernel.

Lets look at  __skb_flow_dissect working on the double-tagged vlan packet.
Here is the relevant code from around net/core/flow_dissector.c:1277
copy-pasted here for convenience:

	if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
	    skb && skb_vlan_tag_present(skb)) {
		proto = skb->protocol;
	} else {
		vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
					    data, hlen, &_vlan);
		if (!vlan) {
			fdret = FLOW_DISSECT_RET_OUT_BAD;
			break;
		}

		proto = vlan->h_vlan_encapsulated_proto;
		nhoff += sizeof(*vlan);
	}

The "else" clause above gets the protocol of the encapsulated packet from
the skb data at the network header location. printk debugging has showed
that in the good double-tagged packet case proto is
htons(0x800 == ETH_P_IP) as expected. However in the single-tagged packet
case proto is garbage leading to the failure to match tc filter 30.

proto is being set from the skb header pointed by nhoff parameter which is
defined at the beginning of __skb_flow_dissect
(net/core/flow_dissector.c:1055 in the current version):

		nhoff = skb_network_offset(skb);

Therefore the culprit seems to be that the skb network offset is different
between double-tagged packet received from the interface and single-tagged
packet having its vlan tag pushed by TC.

Lets look at the interesting points of the lifetime of the single/double
tagged packets as they traverse our packet flow.

Both of them will start at __netif_receive_skb_core where the first vlan
tag will be stripped:

	if (eth_type_vlan(skb->protocol)) {
		skb = skb_vlan_untag(skb);
		if (unlikely(!skb))
			goto out;
	}

At this stage in double-tagged case skb->data points to the second vlan tag
while in single-tagged case skb->data points to the network (eg. IP)
header.

Looking at TC vlan push action (net/sched/act_vlan.c) we have the following
code at tcf_vlan_act (interesting points are in square brackets):

	if (skb_at_tc_ingress(skb))
[1]		skb_push_rcsum(skb, skb->mac_len);

	....

	case TCA_VLAN_ACT_PUSH:
		err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
				    (p->tcfv_push_prio << VLAN_PRIO_SHIFT),
				    0);
		if (err)
			goto drop;
		break;

	....

out:
	if (skb_at_tc_ingress(skb))
[3]		skb_pull_rcsum(skb, skb->mac_len);

And skb_vlan_push (net/core/skbuff.c:6204) function does:

		err = __vlan_insert_tag(skb, skb->vlan_proto,
					skb_vlan_tag_get(skb));
		if (err)
			return err;

		skb->protocol = skb->vlan_proto;
[2]		skb->mac_len += VLAN_HLEN;

in the case of pushing the second tag. Lets look at what happens with
skb->data of the single-tagged packet at each of the above points:

1. As a result of the skb_push_rcsum, skb->data is moved back to the start
   of the packet.

2. First VLAN tag is moved from the skb into packet buffer, skb->mac_len is
   incremented, skb->data still points to the start of the packet.

3. As a result of the skb_pull_rcsum, skb->data is moved forward by the
   modified skb->mac_len, thus pointing to the network header again.

Then __skb_flow_dissect will get confused by having double-tagged vlan
packet with the skb->data at the network header.

The solution for the bug is to preserve "skb->data at second vlan header"
semantics in the skb_vlan_push function. We do this by manipulating
skb->network_header rather than skb->mac_len. skb_vlan_push callers are
updated to do skb_reset_mac_len.

Signed-off-by: Boris Sukholitko <boris.sukholitko@broadcom.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-08-27 11:37:42 +02:00
Jakub Kicinski
761d527d5d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

drivers/net/ethernet/broadcom/bnxt/bnxt.h
  c948c0973d ("bnxt_en: Don't clear ntuple filters and rss contexts during ethtool ops")
  f2878cdeb7 ("bnxt_en: Add support to call FW to update a VNIC")

Link: https://patch.msgid.link/20240822210125.1542769-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-22 17:06:18 -07:00
Stephen Hemminger
c07ff8592d netem: fix return value if duplicate enqueue fails
There is a bug in netem_enqueue() introduced by
commit 5845f70638 ("net: netem: fix skb length BUG_ON in __skb_to_sgvec")
that can lead to a use-after-free.

This commit made netem_enqueue() always return NET_XMIT_SUCCESS
when a packet is duplicated, which can cause the parent qdisc's q.qlen
to be mistakenly incremented. When this happens qlen_notify() may be
skipped on the parent during destruction, leaving a dangling pointer
for some classful qdiscs like DRR.

There are two ways for the bug happen:

- If the duplicated packet is dropped by rootq->enqueue() and then
  the original packet is also dropped.
- If rootq->enqueue() sends the duplicated packet to a different qdisc
  and the original packet is dropped.

In both cases NET_XMIT_SUCCESS is returned even though no packets
are enqueued at the netem qdisc.

The fix is to defer the enqueue of the duplicate packet until after
the original packet has been guaranteed to return NET_XMIT_SUCCESS.

Fixes: 5845f70638 ("net: netem: fix skb length BUG_ON in __skb_to_sgvec")
Reported-by: Budimir Markovic <markovicbudimir@gmail.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240819175753.5151-1-stephen@networkplumber.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-20 17:03:34 -07:00
Gustavo A. R. Silva
e2d0fadd70 sched: act_ct: avoid -Wflex-array-member-not-at-end warning
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

Remove unnecessary flex-array member `pad[]` and refactor the related
code a bit.

Fix the following warning:
net/sched/act_ct.c:57:29: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://patch.msgid.link/ZrY0JMVsImbDbx6r@cute
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-12 17:54:24 -07:00
Eric Dumazet
2191a54f63 sched: act_ct: take care of padding in struct zones_ht_key
Blamed commit increased lookup key size from 2 bytes to 16 bytes,
because zones_ht_key got a struct net pointer.

Make sure rhashtable_lookup() is not using the padding bytes
which are not initialized.

 BUG: KMSAN: uninit-value in rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
 BUG: KMSAN: uninit-value in __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
 BUG: KMSAN: uninit-value in rhashtable_lookup include/linux/rhashtable.h:646 [inline]
 BUG: KMSAN: uninit-value in rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
 BUG: KMSAN: uninit-value in tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329
  rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
  __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
  rhashtable_lookup include/linux/rhashtable.h:646 [inline]
  rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
  tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329
  tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408
  tcf_action_init_1+0x6cc/0xb30 net/sched/act_api.c:1425
  tcf_action_init+0x458/0xf00 net/sched/act_api.c:1488
  tcf_action_add net/sched/act_api.c:2061 [inline]
  tc_ctl_action+0x4be/0x19d0 net/sched/act_api.c:2118
  rtnetlink_rcv_msg+0x12fc/0x1410 net/core/rtnetlink.c:6647
  netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2550
  rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6665
  netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
  netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1357
  netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1901
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x30f/0x380 net/socket.c:745
  ____sys_sendmsg+0x877/0xb60 net/socket.c:2597
  ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2651
  __sys_sendmsg net/socket.c:2680 [inline]
  __do_sys_sendmsg net/socket.c:2689 [inline]
  __se_sys_sendmsg net/socket.c:2687 [inline]
  __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2687
  x64_sys_call+0x2dd6/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:47
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Local variable key created at:
  tcf_ct_flow_table_get+0x4a/0x2260 net/sched/act_ct.c:324
  tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408

Fixes: 88c67aeb14 ("sched: act_ct: add netns into the key of tcf_ct_flow_table")
Reported-by: syzbot+1b5e4e187cc586d05ea0@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-07-26 11:22:57 +01:00
Asbjørn Sloth Tønnesen
536b97acdd net/sched: cls_flower: propagate tca[TCA_OPTIONS] to NL_REQ_ATTR_CHECK
NL_REQ_ATTR_CHECK() is used in fl_set_key_flags() to set
extended attributes about the origin of an error, this
patch propagates tca[TCA_OPTIONS] through.

Before this patch:

$ sudo ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/tc.yaml \
	 --do newtfilter --json '{
		"chain": 0, "family": 0, "handle": 4, "ifindex": 22,
		"info": 262152,
		"kind": "flower",
		"options": {
			"flags": 0, "key-enc-flags": 8,
			"key-eth-type": 2048 },
		"parent": 4294967283 }'
Netlink error: Invalid argument
nl_len = 68 (52) nl_flags = 0x300 nl_type = 2
        error: -22
        extack: {'msg': 'Missing flags mask',
                 'miss-type': 111}

After this patch:

[same cmd]
Netlink error: Invalid argument
nl_len = 76 (60) nl_flags = 0x300 nl_type = 2
        error: -22
        extack: {'msg': 'Missing flags mask',
                 'miss-type': 111, 'miss-nest': 56}

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Link: https://patch.msgid.link/20240713021911.1631517-14-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-15 09:14:39 -07:00
Asbjørn Sloth Tønnesen
706bf4f44c flow_dissector: set encapsulation control flags for non-IP
Make sure to set encapsulated control flags also for non-IP
packets, such that it's possible to allow matching on e.g.
TUNNEL_OAM on a geneve packet carrying a non-IP packet.

Suggested-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20240713021911.1631517-13-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-15 09:14:39 -07:00
Asbjørn Sloth Tønnesen
db5271d50e flow_dissector: cleanup FLOW_DISSECTOR_KEY_ENC_FLAGS
Now that TCA_FLOWER_KEY_ENC_FLAGS is unused, as it's
former data is stored behind TCA_FLOWER_KEY_ENC_CONTROL,
then remove the last bits of FLOW_DISSECTOR_KEY_ENC_FLAGS.

FLOW_DISSECTOR_KEY_ENC_FLAGS is unreleased, and have been
in net-next since 2024-06-04.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20240713021911.1631517-12-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-15 09:14:39 -07:00
Asbjørn Sloth Tønnesen
11036bd7a0 net/sched: cls_flower: rework TCA_FLOWER_KEY_ENC_FLAGS usage
This patch changes how TCA_FLOWER_KEY_ENC_FLAGS is used, so that
it is used with TCA_FLOWER_KEY_FLAGS_* flags, in the same way as
TCA_FLOWER_KEY_FLAGS is currently used.

Where TCA_FLOWER_KEY_FLAGS uses {key,mask}->control.flags, then
TCA_FLOWER_KEY_ENC_FLAGS now uses {key,mask}->enc_control.flags,
therefore {key,mask}->enc_flags is now unused.

As the generic fl_set_key_flags/fl_dump_key_flags() is used with
encap set to true, then fl_{set,dump}_key_enc_flags() is removed.

This breaks unreleased userspace API (net-next since 2024-06-04).

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20240713021911.1631517-10-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-15 09:14:38 -07:00
Asbjørn Sloth Tønnesen
988f8723d3 net/sched: cls_flower: add tunnel flags to fl_{set,dump}_key_flags()
Prepare to set and dump the tunnel flags.

This code won't see any of these flags yet, as these flags
aren't allowed by the NLA_POLICY_MASK, and the functions
doesn't get called with encap set to true yet.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20240713021911.1631517-9-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-15 09:14:38 -07:00
Asbjørn Sloth Tønnesen
0e83a7875d net/sched: cls_flower: add policy for TCA_FLOWER_KEY_FLAGS
This policy guards fl_set_key_flags() from seeing flags
not used in the context of TCA_FLOWER_KEY_FLAGS.

In order For the policy check to be performed with the
correct endianness, then we also needs to change the
attribute type to NLA_BE32 (Thanks Davide).

TCA_FLOWER_KEY_FLAGS{,_MASK} already has a be32 comment
in include/uapi/linux/pkt_cls.h.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20240713021911.1631517-6-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-15 09:14:38 -07:00
Asbjørn Sloth Tønnesen
fcb4bb07a9 net/sched: cls_flower: prepare fl_{set,dump}_key_flags() for ENC_FLAGS
Prepare fl_set_key_flags/fl_dump_key_flags() for use with
TCA_FLOWER_KEY_ENC_FLAGS{,_MASK}.

This patch adds an encap argument, similar to fl_set_key_ip/
fl_dump_key_ip(), and determine the flower keys based on the
encap argument, and use them in the rest of the two functions.

Since these functions are so far, only called with encap set false,
then there is no functional change.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20240713021911.1631517-5-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-15 09:14:38 -07:00
Jakub Kicinski
30b3560050 Merge branch 'net-make-timestamping-selectable'
First part of "net: Make timestamping selectable" from Kory Maincent.
Change the driver-facing type already to lower rebasing pain.

Link: https://lore.kernel.org/20240709-feature_ptp_netnext-v17-0-b5317f50df2a@bootlin.com/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-15 08:02:30 -07:00
Kory Maincent
2111375b85 net: Add struct kernel_ethtool_ts_info
In prevision to add new UAPI for hwtstamp we will be limited to the struct
ethtool_ts_info that is currently passed in fixed binary format through the
ETHTOOL_GET_TS_INFO ethtool ioctl. It would be good if new kernel code
already started operating on an extensible kernel variant of that
structure, similar in concept to struct kernel_hwtstamp_config vs struct
hwtstamp_config.

Since struct ethtool_ts_info is in include/uapi/linux/ethtool.h, here
we introduce the kernel-only structure in include/linux/ethtool.h.
The manual copy is then made in the function called by ETHTOOL_GET_TS_INFO.

Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Acked-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20240709-feature_ptp_netnext-v17-6-b5317f50df2a@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-15 08:02:26 -07:00
Chen Ni
b07593edd2 net/sched: act_skbmod: convert comma to semicolon
Replace a comma between expression statements by a semicolon.

Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240709072838.1152880-1-nichen@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-11 17:12:15 -07:00
Jakub Kicinski
7c8267275d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/sched/act_ct.c
  26488172b0 ("net/sched: Fix UAF when resolving a clash")
  3abbd7ed8b ("act_ct: prepare for stolen verdict coming from conntrack and nat engine")

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-11 12:58:13 -07:00
Chengen Du
26488172b0 net/sched: Fix UAF when resolving a clash
KASAN reports the following UAF:

 BUG: KASAN: slab-use-after-free in tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct]
 Read of size 1 at addr ffff888c07603600 by task handler130/6469

 Call Trace:
  <IRQ>
  dump_stack_lvl+0x48/0x70
  print_address_description.constprop.0+0x33/0x3d0
  print_report+0xc0/0x2b0
  kasan_report+0xd0/0x120
  __asan_load1+0x6c/0x80
  tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct]
  tcf_ct_act+0x886/0x1350 [act_ct]
  tcf_action_exec+0xf8/0x1f0
  fl_classify+0x355/0x360 [cls_flower]
  __tcf_classify+0x1fd/0x330
  tcf_classify+0x21c/0x3c0
  sch_handle_ingress.constprop.0+0x2c5/0x500
  __netif_receive_skb_core.constprop.0+0xb25/0x1510
  __netif_receive_skb_list_core+0x220/0x4c0
  netif_receive_skb_list_internal+0x446/0x620
  napi_complete_done+0x157/0x3d0
  gro_cell_poll+0xcf/0x100
  __napi_poll+0x65/0x310
  net_rx_action+0x30c/0x5c0
  __do_softirq+0x14f/0x491
  __irq_exit_rcu+0x82/0xc0
  irq_exit_rcu+0xe/0x20
  common_interrupt+0xa1/0xb0
  </IRQ>
  <TASK>
  asm_common_interrupt+0x27/0x40

 Allocated by task 6469:
  kasan_save_stack+0x38/0x70
  kasan_set_track+0x25/0x40
  kasan_save_alloc_info+0x1e/0x40
  __kasan_krealloc+0x133/0x190
  krealloc+0xaa/0x130
  nf_ct_ext_add+0xed/0x230 [nf_conntrack]
  tcf_ct_act+0x1095/0x1350 [act_ct]
  tcf_action_exec+0xf8/0x1f0
  fl_classify+0x355/0x360 [cls_flower]
  __tcf_classify+0x1fd/0x330
  tcf_classify+0x21c/0x3c0
  sch_handle_ingress.constprop.0+0x2c5/0x500
  __netif_receive_skb_core.constprop.0+0xb25/0x1510
  __netif_receive_skb_list_core+0x220/0x4c0
  netif_receive_skb_list_internal+0x446/0x620
  napi_complete_done+0x157/0x3d0
  gro_cell_poll+0xcf/0x100
  __napi_poll+0x65/0x310
  net_rx_action+0x30c/0x5c0
  __do_softirq+0x14f/0x491

 Freed by task 6469:
  kasan_save_stack+0x38/0x70
  kasan_set_track+0x25/0x40
  kasan_save_free_info+0x2b/0x60
  ____kasan_slab_free+0x180/0x1f0
  __kasan_slab_free+0x12/0x30
  slab_free_freelist_hook+0xd2/0x1a0
  __kmem_cache_free+0x1a2/0x2f0
  kfree+0x78/0x120
  nf_conntrack_free+0x74/0x130 [nf_conntrack]
  nf_ct_destroy+0xb2/0x140 [nf_conntrack]
  __nf_ct_resolve_clash+0x529/0x5d0 [nf_conntrack]
  nf_ct_resolve_clash+0xf6/0x490 [nf_conntrack]
  __nf_conntrack_confirm+0x2c6/0x770 [nf_conntrack]
  tcf_ct_act+0x12ad/0x1350 [act_ct]
  tcf_action_exec+0xf8/0x1f0
  fl_classify+0x355/0x360 [cls_flower]
  __tcf_classify+0x1fd/0x330
  tcf_classify+0x21c/0x3c0
  sch_handle_ingress.constprop.0+0x2c5/0x500
  __netif_receive_skb_core.constprop.0+0xb25/0x1510
  __netif_receive_skb_list_core+0x220/0x4c0
  netif_receive_skb_list_internal+0x446/0x620
  napi_complete_done+0x157/0x3d0
  gro_cell_poll+0xcf/0x100
  __napi_poll+0x65/0x310
  net_rx_action+0x30c/0x5c0
  __do_softirq+0x14f/0x491

The ct may be dropped if a clash has been resolved but is still passed to
the tcf_ct_flow_table_process_conn function for further usage. This issue
can be fixed by retrieving ct from skb again after confirming conntrack.

Fixes: 0cc254e5aa ("net/sched: act_ct: Offload connections with commit action")
Co-developed-by: Gerald Yang <gerald.yang@canonical.com>
Signed-off-by: Gerald Yang <gerald.yang@canonical.com>
Signed-off-by: Chengen Du <chengen.du@canonical.com>
Link: https://patch.msgid.link/20240710053747.13223-1-chengen.du@canonical.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-07-11 12:07:54 +02:00
Daniel Borkmann
1cb6f0bae5 bpf: Fix too early release of tcx_entry
Pedro Pinto and later independently also Hyunwoo Kim and Wongi Lee reported
an issue that the tcx_entry can be released too early leading to a use
after free (UAF) when an active old-style ingress or clsact qdisc with a
shared tc block is later replaced by another ingress or clsact instance.

Essentially, the sequence to trigger the UAF (one example) can be as follows:

  1. A network namespace is created
  2. An ingress qdisc is created. This allocates a tcx_entry, and
     &tcx_entry->miniq is stored in the qdisc's miniqp->p_miniq. At the
     same time, a tcf block with index 1 is created.
  3. chain0 is attached to the tcf block. chain0 must be connected to
     the block linked to the ingress qdisc to later reach the function
     tcf_chain0_head_change_cb_del() which triggers the UAF.
  4. Create and graft a clsact qdisc. This causes the ingress qdisc
     created in step 1 to be removed, thus freeing the previously linked
     tcx_entry:

     rtnetlink_rcv_msg()
       => tc_modify_qdisc()
         => qdisc_create()
           => clsact_init() [a]
         => qdisc_graft()
           => qdisc_destroy()
             => __qdisc_destroy()
               => ingress_destroy() [b]
                 => tcx_entry_free()
                   => kfree_rcu() // tcx_entry freed

  5. Finally, the network namespace is closed. This registers the
     cleanup_net worker, and during the process of releasing the
     remaining clsact qdisc, it accesses the tcx_entry that was
     already freed in step 4, causing the UAF to occur:

     cleanup_net()
       => ops_exit_list()
         => default_device_exit_batch()
           => unregister_netdevice_many()
             => unregister_netdevice_many_notify()
               => dev_shutdown()
                 => qdisc_put()
                   => clsact_destroy() [c]
                     => tcf_block_put_ext()
                       => tcf_chain0_head_change_cb_del()
                         => tcf_chain_head_change_item()
                           => clsact_chain_head_change()
                             => mini_qdisc_pair_swap() // UAF

There are also other variants, the gist is to add an ingress (or clsact)
qdisc with a specific shared block, then to replace that qdisc, waiting
for the tcx_entry kfree_rcu() to be executed and subsequently accessing
the current active qdisc's miniq one way or another.

The correct fix is to turn the miniq_active boolean into a counter. What
can be observed, at step 2 above, the counter transitions from 0->1, at
step [a] from 1->2 (in order for the miniq object to remain active during
the replacement), then in [b] from 2->1 and finally [c] 1->0 with the
eventual release. The reference counter in general ranges from [0,2] and
it does not need to be atomic since all access to the counter is protected
by the rtnl mutex. With this in place, there is no longer a UAF happening
and the tcx_entry is freed at the correct time.

Fixes: e420bed025 ("bpf: Add fd-based tcx multi-prog infra with link support")
Reported-by: Pedro Pinto <xten@osec.io>
Co-developed-by: Pedro Pinto <xten@osec.io>
Signed-off-by: Pedro Pinto <xten@osec.io>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Hyunwoo Kim <v4bel@theori.io>
Cc: Wongi Lee <qwerty@theori.io>
Cc: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240708133130.11609-1-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-07-08 14:07:31 -07:00
Florian Westphal
3abbd7ed8b act_ct: prepare for stolen verdict coming from conntrack and nat engine
At this time, conntrack either returns NF_ACCEPT or NF_DROP.
To improve debuging it would be nice to be able to replace NF_DROP verdict
with NF_DROP_REASON() helper,

This helper releases the skb instantly (so drop_monitor can pinpoint
exact location) and returns NF_STOLEN.

Prepare call sites to deal with this before introducing such changes
in conntrack and nat core.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-07-08 11:35:31 +01:00
Adrian Moreno
03448444ae net: sched: act_sample: add action cookie to sample
If the action has a user_cookie, pass it along to the sample so it can
be easily identified.

Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Link: https://patch.msgid.link/20240704085710.353845-3-amorenoz@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-05 17:45:47 -07:00
Jakub Kicinski
a6ec08beec Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/ethernet/broadcom/bnxt/bnxt.c
  1e7962114c ("bnxt_en: Restore PTP tx_avail count in case of skb_pad() error")
  165f87691a ("bnxt_en: add timestamping statistics support")

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-20 13:49:59 -07:00
Xin Long
88c67aeb14 sched: act_ct: add netns into the key of tcf_ct_flow_table
zones_ht is a global hashtable for flow_table with zone as key. However,
it does not consider netns when getting a flow_table from zones_ht in
tcf_ct_init(), and it means an act_ct action in netns A may get a
flow_table that belongs to netns B if it has the same zone value.

In Shuang's test with the TOPO:

  tcf2_c <---> tcf2_sw1 <---> tcf2_sw2 <---> tcf2_s

tcf2_sw1 and tcf2_sw2 saw the same flow and used the same flow table,
which caused their ct entries entering unexpected states and the
TCP connection not able to end normally.

This patch fixes the issue simply by adding netns into the key of
tcf_ct_flow_table so that an act_ct action gets a flow_table that
belongs to its own netns in tcf_ct_init().

Note that for easy coding we don't use tcf_ct_flow_table.nf_ft.net,
as the ct_ft is initialized after inserting it to the hashtable in
tcf_ct_flow_table_get() and also it requires to implement several
functions in rhashtable_params including hashfn, obj_hashfn and
obj_cmpfn.

Fixes: 64ff70b80f ("net/sched: act_ct: Offload established connections to flow table")
Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/1db5b6cc6902c5fc6f8c6cbd85494a2008087be5.1718488050.git.lucien.xin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-18 15:24:24 +02:00
David Ruth
d864319871 net/sched: act_api: fix possible infinite loop in tcf_idr_check_alloc()
syzbot found hanging tasks waiting on rtnl_lock [1]

A reproducer is available in the syzbot bug.

When a request to add multiple actions with the same index is sent, the
second request will block forever on the first request. This holds
rtnl_lock, and causes tasks to hang.

Return -EAGAIN to prevent infinite looping, while keeping documented
behavior.

[1]

INFO: task kworker/1:0:5088 blocked for more than 143 seconds.
Not tainted 6.9.0-rc4-syzkaller-00173-g3cdb45594619 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0 state:D stack:23744 pid:5088 tgid:5088 ppid:2 flags:0x00004000
Workqueue: events_power_efficient reg_check_chans_work
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5409 [inline]
__schedule+0xf15/0x5d00 kernel/sched/core.c:6746
__schedule_loop kernel/sched/core.c:6823 [inline]
schedule+0xe7/0x350 kernel/sched/core.c:6838
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895
__mutex_lock_common kernel/locking/mutex.c:684 [inline]
__mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752
wiphy_lock include/net/cfg80211.h:5953 [inline]
reg_leave_invalid_chans net/wireless/reg.c:2466 [inline]
reg_check_chans_work+0x10a/0x10e0 net/wireless/reg.c:2481

Fixes: 0190c1d452 ("net: sched: atomically check-allocate action")
Reported-by: syzbot+b87c222546179f4513a7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=b87c222546179f4513a7
Signed-off-by: David Ruth <druth@chromium.org>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20240614190326.1349786-1-druth@chromium.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-18 12:28:01 +02:00
Jakub Kicinski
4c7d3d79c7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts, no adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-13 13:13:46 -07:00
Johannes Berg
44180feacc net/sched: initialize noop_qdisc owner
When the noop_qdisc owner isn't initialized, then it will be 0,
so packets will erroneously be regarded as having been subject
to recursion as long as only CPU 0 queues them. For non-SMP,
that's all packets, of course. This causes a change in what's
reported to userspace, normally noop_qdisc would drop packets
silently, but with this change the syscall returns -ENOBUFS if
RECVERR is also set on the socket.

Fix this by initializing the owner field to -1, just like it
would be for dynamically allocated qdiscs by qdisc_alloc().

Fixes: 0f022d32c3 ("net/sched: Fix mirred deadlock on device recursion")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240607175340.786bfb938803.I493bf8422e36be4454c08880a8d3703cea8e421a@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-10 19:36:49 -07:00
Jakub Kicinski
62b5bf58b9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

drivers/net/ethernet/pensando/ionic/ionic_txrx.c
  d9c0420999 ("ionic: Mark error paths in the data path as unlikely")
  491aee894a ("ionic: fix kernel panic in XDP_TX action")

net/ipv6/ip6_fib.c
  b4cb4a1391 ("net: use unrcu_pointer() helper")
  b01e1c0307 ("ipv6: fix possible race in __fib6_drop_pcpu_from()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-06 12:06:56 -07:00
Eric Dumazet
b4cb4a1391 net: use unrcu_pointer() helper
Toke mentioned unrcu_pointer() existence, allowing
to remove some of the ugly casts we have when using
xchg() for rcu protected pointers.

Also make inet_rcv_compat const.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20240604111603.45871-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-06 11:52:52 +02:00
Eric Dumazet
f921a58ae2 net/sched: taprio: always validate TCA_TAPRIO_ATTR_PRIOMAP
If one TCA_TAPRIO_ATTR_PRIOMAP attribute has been provided,
taprio_parse_mqprio_opt() must validate it, or userspace
can inject arbitrary data to the kernel, the second time
taprio_change() is called.

First call (with valid attributes) sets dev->num_tc
to a non zero value.

Second call (with arbitrary mqprio attributes)
returns early from taprio_parse_mqprio_opt()
and bad things can happen.

Fixes: a3d43c0d56 ("taprio: Add support adding an admin schedule")
Reported-by: Noam Rathaus <noamr@ssd-disclosure.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20240604181511.769870-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-05 15:54:51 -07:00
Hangyu Hua
affc18fdc6 net: sched: sch_multiq: fix possible OOB write in multiq_tune()
q->bands will be assigned to qopt->bands to execute subsequent code logic
after kmalloc. So the old q->bands should not be used in kmalloc.
Otherwise, an out-of-bounds write will occur.

Fixes: c2999f7fb0 ("net: sched: multiq: don't call qdisc_put() while holding tree lock")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Acked-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-06-05 10:50:19 +01:00
Davide Caratti
1d17568e74 net/sched: cls_flower: add support for matching tunnel control flags
extend cls_flower to match TUNNEL_FLAGS_PRESENT bits in tunnel metadata.

Suggested-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-04 11:16:38 +02:00
Jakub Kicinski
4fdb6b6063 net: count drops due to missing qdisc as dev->tx_drops
Catching and debugging missing qdiscs is pretty tricky. When qdisc
is deleted we replace it with a noop qdisc, which silently drops
all the packets. Since the noop qdisc has a single static instance
we can't count drops at the qdisc level. Count them as dev->tx_drops.

  ip netns add red
  ip link add type veth peer netns red
  ip            link set dev veth0 up
  ip -netns red link set dev veth0 up
  ip            a a dev veth0 10.0.0.1/24
  ip -netns red a a dev veth0 10.0.0.2/24
  ping -c 2 10.0.0.2
  #  2 packets transmitted, 2 received, 0% packet loss, time 1031ms
  ip -s link show dev veth0
  #  TX:  bytes packets errors dropped carrier collsns
  #        1314      17      0       0       0       0

  tc qdisc replace dev veth0 root handle 1234: mq
  tc qdisc replace dev veth0 parent 1234:1 pfifo
  tc qdisc del dev veth0 parent 1234:1
  ping -c 2 10.0.0.2
  #  2 packets transmitted, 0 received, 100% packet loss, time 1034ms
  ip -s link show dev veth0
  #  TX:  bytes packets errors dropped carrier collsns
  #        1314      17      0       3       0       0

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20240529162527.3688979-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-04 10:39:31 +02:00
Jakub Kicinski
e19de2064f Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/ethernet/ti/icssg/icssg_classifier.c
  abd5576b9c ("net: ti: icssg-prueth: Add support for ICSSG switch firmware")
  56a5cf538c ("net: ti: icssg-prueth: Fix start counter for ft1 filter")
https://lore.kernel.org/all/20240531123822.3bb7eadf@canb.auug.org.au/

No other adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-31 14:10:28 -07:00
Vladimir Oltean
fb66df20a7 net/sched: taprio: extend minimum interval restriction to entire cycle too
It is possible for syzbot to side-step the restriction imposed by the
blamed commit in the Fixes: tag, because the taprio UAPI permits a
cycle-time different from (and potentially shorter than) the sum of
entry intervals.

We need one more restriction, which is that the cycle time itself must
be larger than N * ETH_ZLEN bit times, where N is the number of schedule
entries. This restriction needs to apply regardless of whether the cycle
time came from the user or was the implicit, auto-calculated value, so
we move the existing "cycle == 0" check outside the "if "(!new->cycle_time)"
branch. This way covers both conditions and scenarios.

Add a selftest which illustrates the issue triggered by syzbot.

Fixes: b5b73b26b3 ("taprio: Fix allowing too small intervals")
Reported-by: syzbot+a7d2b1d5d1af83035567@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/0000000000007d66bc06196e7c66@google.com/
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20240527153955.553333-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-28 19:46:41 -07:00
Vladimir Oltean
e634134180 net/sched: taprio: make q->picos_per_byte available to fill_sched_entry()
In commit b5b73b26b3 ("taprio: Fix allowing too small intervals"), a
comparison of user input against length_to_duration(q, ETH_ZLEN) was
introduced, to avoid RCU stalls due to frequent hrtimers.

The implementation of length_to_duration() depends on q->picos_per_byte
being set for the link speed. The blamed commit in the Fixes: tag has
moved this too late, so the checks introduced above are ineffective.
The q->picos_per_byte is zero at parse_taprio_schedule() ->
parse_sched_list() -> parse_sched_entry() -> fill_sched_entry() time.

Move the taprio_set_picos_per_byte() call as one of the first things in
taprio_change(), before the bulk of the netlink attribute parsing is
done. That's because it is needed there.

Add a selftest to make sure the issue doesn't get reintroduced.

Fixes: 09dbdf28f9 ("net/sched: taprio: fix calculation of maximum gate durations")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240527153955.553333-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-28 19:46:41 -07:00
Abhishek Chauhan
4d25ca2d68 net: Rename mono_delivery_time to tstamp_type for scalabilty
mono_delivery_time was added to check if skb->tstamp has delivery
time in mono clock base (i.e. EDT) otherwise skb->tstamp has
timestamp in ingress and delivery_time at egress.

Renaming the bitfield from mono_delivery_time to tstamp_type is for
extensibilty for other timestamps such as userspace timestamp
(i.e. SO_TXTIME) set via sock opts.

As we are renaming the mono_delivery_time to tstamp_type, it makes
sense to start assigning tstamp_type based on enum defined
in this commit.

Earlier we used bool arg flag to check if the tstamp is mono in
function skb_set_delivery_time, Now the signature of the functions
accepts tstamp_type to distinguish between mono and real time.

Also skb_set_delivery_type_by_clockid is a new function which accepts
clockid to determine the tstamp_type.

In future tstamp_type:1 can be extended to support userspace timestamp
by increasing the bitfield.

Signed-off-by: Abhishek Chauhan <quic_abchauha@quicinc.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240509211834.3235191-2-quic_abchauha@quicinc.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-23 14:14:23 -07:00
Praveen Kumar Kannoju
33fb988b67 net/sched: adjust device watchdog timer to detect stopped queue at right time
Applications are sensitive to long network latency, particularly
heartbeat monitoring ones. Longer the tx timeout recovery higher the
risk with such applications on a production machines. This patch
remedies, yet honoring device set tx timeout.

Modify watchdog next timeout to be shorter than the device specified.
Compute the next timeout be equal to device watchdog timeout less the
how long ago queue stop had been done. At next watchdog timeout tx
timeout handler is called into if still in stopped state. Either called
or not called, restore the watchdog timeout back to device specified.

Signed-off-by: Praveen Kumar Kannoju <praveen.kannoju@oracle.com>
Link: https://lore.kernel.org/r/20240508133617.4424-1-praveen.kannoju@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-09 20:24:13 -07:00
Eric Dumazet
1eb2cded45 net: annotate writes on dev->mtu from ndo_change_mtu()
Simon reported that ndo_change_mtu() methods were never
updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted
in commit 501a90c945 ("inet: protect against too small
mtu values.")

We read dev->mtu without holding RTNL in many places,
with READ_ONCE() annotations.

It is time to take care of ndo_change_mtu() methods
to use corresponding WRITE_ONCE()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Simon Horman <horms@kernel.org>
Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-07 16:19:14 -07:00
Eric Dumazet
ad13b5b0d1 rtnetlink: do not depend on RTNL for IFLA_TXQLEN output
rtnl_fill_ifinfo() can read dev->tx_queue_len locklessly,
granted we add corresponding READ_ONCE()/WRITE_ONCE() annotations.

Add missing READ_ONCE(dev->tx_queue_len) in teql_enqueue()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-07 11:14:50 +02:00
Eric Dumazet
a17ef9e6c2 net_sched: sch_sfq: annotate data-races around q->perturb_period
sfq_perturbation() reads q->perturb_period locklessly.
Add annotations to fix potential issues.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240430180015.3111398-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-02 19:01:35 -07:00
Davide Caratti
86735b57c9 net/sched: unregister lockdep keys in qdisc_create/qdisc_alloc error path
Naresh and Eric report several errors (corrupted elements in the dynamic
key hash list), when running tdc.py or syzbot. The error path of
qdisc_alloc() and qdisc_create() frees the qdisc memory, but it forgets
to unregister the lockdep key, thus causing use-after-free like the
following one:

 ==================================================================
 BUG: KASAN: slab-use-after-free in lockdep_register_key+0x5f2/0x700
 Read of size 8 at addr ffff88811236f2a8 by task ip/7925

 CPU: 26 PID: 7925 Comm: ip Kdump: loaded Not tainted 6.9.0-rc2+ #648
 Hardware name: Supermicro SYS-6027R-72RF/X9DRH-7TF/7F/iTF/iF, BIOS 3.0  07/26/2013
 Call Trace:
  <TASK>
  dump_stack_lvl+0x7c/0xc0
  print_report+0xc9/0x610
  kasan_report+0x89/0xc0
  lockdep_register_key+0x5f2/0x700
  qdisc_alloc+0x21d/0xb60
  qdisc_create_dflt+0x63/0x3c0
  attach_one_default_qdisc.constprop.37+0x8e/0x170
  dev_activate+0x4bd/0xc30
  __dev_open+0x275/0x380
  __dev_change_flags+0x3f1/0x570
  dev_change_flags+0x7c/0x160
  do_setlink+0x1ea1/0x34b0
  __rtnl_newlink+0x8c9/0x1510
  rtnl_newlink+0x61/0x90
  rtnetlink_rcv_msg+0x2f0/0xbc0
  netlink_rcv_skb+0x120/0x380
  netlink_unicast+0x420/0x630
  netlink_sendmsg+0x732/0xbc0
  __sock_sendmsg+0x1ea/0x280
  ____sys_sendmsg+0x5a9/0x990
  ___sys_sendmsg+0xf1/0x180
  __sys_sendmsg+0xd3/0x180
  do_syscall_64+0x96/0x180
  entry_SYSCALL_64_after_hwframe+0x71/0x79
 RIP: 0033:0x7f9503f4fa07
 Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 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> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
 RSP: 002b:00007fff6c729068 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
 RAX: ffffffffffffffda RBX: 000000006630c681 RCX: 00007f9503f4fa07
 RDX: 0000000000000000 RSI: 00007fff6c7290d0 RDI: 0000000000000003
 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000078
 R10: 000000000000009b R11: 0000000000000246 R12: 0000000000000001
 R13: 00007fff6c729180 R14: 0000000000000000 R15: 000055bf67dd9040
  </TASK>

 Allocated by task 7745:
  kasan_save_stack+0x1c/0x40
  kasan_save_track+0x10/0x30
  __kasan_kmalloc+0x7b/0x90
  __kmalloc_node+0x1ff/0x460
  qdisc_alloc+0xae/0xb60
  qdisc_create+0xdd/0xfb0
  tc_modify_qdisc+0x37e/0x1960
  rtnetlink_rcv_msg+0x2f0/0xbc0
  netlink_rcv_skb+0x120/0x380
  netlink_unicast+0x420/0x630
  netlink_sendmsg+0x732/0xbc0
  __sock_sendmsg+0x1ea/0x280
  ____sys_sendmsg+0x5a9/0x990
  ___sys_sendmsg+0xf1/0x180
  __sys_sendmsg+0xd3/0x180
  do_syscall_64+0x96/0x180
  entry_SYSCALL_64_after_hwframe+0x71/0x79

 Freed by task 7745:
  kasan_save_stack+0x1c/0x40
  kasan_save_track+0x10/0x30
  kasan_save_free_info+0x36/0x60
  __kasan_slab_free+0xfe/0x180
  kfree+0x113/0x380
  qdisc_create+0xafb/0xfb0
  tc_modify_qdisc+0x37e/0x1960
  rtnetlink_rcv_msg+0x2f0/0xbc0
  netlink_rcv_skb+0x120/0x380
  netlink_unicast+0x420/0x630
  netlink_sendmsg+0x732/0xbc0
  __sock_sendmsg+0x1ea/0x280
  ____sys_sendmsg+0x5a9/0x990
  ___sys_sendmsg+0xf1/0x180
  __sys_sendmsg+0xd3/0x180
  do_syscall_64+0x96/0x180
  entry_SYSCALL_64_after_hwframe+0x71/0x79

Fix this ensuring that lockdep_unregister_key() is called before the
qdisc struct is freed, also in the error path of qdisc_create() and
qdisc_alloc().

Fixes: af0cb3fa3f ("net/sched: fix false lockdep warning on qdisc root lock")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/netdev/20240429221706.1492418-1-naresh.kamboju@linaro.org/
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/2aa1ca0c0a3aa0acc15925c666c777a4b5de553c.1714496886.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-02 07:12:40 -07:00
Davide Caratti
af0cb3fa3f net/sched: fix false lockdep warning on qdisc root lock
Xiumei and Christoph reported the following lockdep splat, complaining of
the qdisc root lock being taken twice:

 ============================================
 WARNING: possible recursive locking detected
 6.7.0-rc3+ #598 Not tainted
 --------------------------------------------
 swapper/2/0 is trying to acquire lock:
 ffff888177190110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70

 but task is already holding lock:
 ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&sch->q.lock);
   lock(&sch->q.lock);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 5 locks held by swapper/2/0:
  #0: ffff888135a09d98 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x510
  #1: ffffffffaaee5260 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x2c0/0x1ed0
  #2: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70
  #3: ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70
  #4: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70

 stack backtrace:
 CPU: 2 PID: 0 Comm: swapper/2 Not tainted 6.7.0-rc3+ #598
 Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014
 Call Trace:
  <IRQ>
  dump_stack_lvl+0x4a/0x80
  __lock_acquire+0xfdd/0x3150
  lock_acquire+0x1ca/0x540
  _raw_spin_lock+0x34/0x80
  __dev_queue_xmit+0x1560/0x2e70
  tcf_mirred_act+0x82e/0x1260 [act_mirred]
  tcf_action_exec+0x161/0x480
  tcf_classify+0x689/0x1170
  prio_enqueue+0x316/0x660 [sch_prio]
  dev_qdisc_enqueue+0x46/0x220
  __dev_queue_xmit+0x1615/0x2e70
  ip_finish_output2+0x1218/0x1ed0
  __ip_finish_output+0x8b3/0x1350
  ip_output+0x163/0x4e0
  igmp_ifc_timer_expire+0x44b/0x930
  call_timer_fn+0x1a2/0x510
  run_timer_softirq+0x54d/0x11a0
  __do_softirq+0x1b3/0x88f
  irq_exit_rcu+0x18f/0x1e0
  sysvec_apic_timer_interrupt+0x6f/0x90
  </IRQ>

This happens when TC does a mirred egress redirect from the root qdisc of
device A to the root qdisc of device B. As long as these two locks aren't
protecting the same qdisc, they can be acquired in chain: add a per-qdisc
lockdep key to silence false warnings.
This dynamic key should safely replace the static key we have in sch_htb:
it was added to allow enqueueing to the device "direct qdisc" while still
holding the qdisc root lock.

v2: don't use static keys anymore in HTB direct qdiscs (thanks Eric Dumazet)

CC: Maxim Mikityanskiy <maxim@isovalent.com>
CC: Xiumei Mu <xmu@redhat.com>
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/451
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/7dc06d6158f72053cf877a82e2a7a5bd23692faa.1713448007.git.dcaratti@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-26 10:46:41 +02:00