linux-stable.git/net, branch v5.4.97

net: ip_tunnel: fix mtu calculation

2021-02-10T08:25:32+00:00

commit 28e104d00281ade30250b24e098bf50887671ea4 upstream.

dev->hard_header_len for tunnel interface is set only when header_ops
are set too and already contains full overhead of any tunnel encapsulation.
That's why there is not need to use this overhead twice in mtu calc.

Fixes: fdafed459998 ("ip_gre: set dev->hard_header_len and dev->needed_headroom properly")
Reported-by: Slava Bacherikov 
Signed-off-by: Vadim Fedorenko 
Link: https://lore.kernel.org/r/1611959267-20536-1-git-send-email-vfedorenko@novek.ru
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

neighbour: Prevent a dead entry from updating gc_list

2021-02-10T08:25:32+00:00

commit eb4e8fac00d1e01ada5e57c05d24739156086677 upstream.

Following race condition was detected:
 - neigh_flush_dev() is under execution and calls
neigh_mark_dead(n) marking the neighbour entry 'n' as dead.

 - Executing: __netif_receive_skb() ->
__netif_receive_skb_core() -> arp_rcv() -> arp_process().arp_process()
calls __neigh_lookup() which takes a reference on neighbour entry 'n'.

 - Moves further along neigh_flush_dev() and calls
neigh_cleanup_and_release(n), but since reference count increased in t2,
'n' couldn't be destroyed.

 - Moves further along, arp_process() and calls
neigh_update()-> __neigh_update() -> neigh_update_gc_list(), which adds
the neighbour entry back in gc_list(neigh_mark_dead(), removed it
earlier in t0 from gc_list)

 - arp_process() finally calls neigh_release(n), destroying
the neighbour entry.

This leads to 'n' still being part of gc_list, but the actual
neighbour structure has been freed.

The situation can be prevented from happening if we disallow a dead
entry to have any possibility of updating gc_list. This is what the
patch intends to achieve.

Fixes: 9c29a2f55ec0 ("neighbor: Fix locking order for gc_list changes")
Signed-off-by: Chinmay Agarwal 
Reviewed-by: Cong Wang 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20210127165453.GA20514@chinagar-linux.qualcomm.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

mac80211: fix station rate table updates on assoc

2021-02-10T08:25:29+00:00

commit 18fe0fae61252b5ae6e26553e2676b5fac555951 upstream.

If the driver uses .sta_add, station entries are only uploaded after the sta
is in assoc state. Fix early station rate table updates by deferring them
until the sta has been uploaded.

Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau 
Link: https://lore.kernel.org/r/20210201083324.3134-1-nbd@nbd.name
[use rcu_access_pointer() instead since we won't dereference here]
Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

net: lapb: Copy the skb before sending a packet

2021-02-10T08:25:28+00:00

[ Upstream commit 88c7a9fd9bdd3e453f04018920964c6f848a591a ]

When sending a packet, we will prepend it with an LAPB header.
This modifies the shared parts of a cloned skb, so we should copy the
skb rather than just clone it, before we prepend the header.

In "Documentation/networking/driver.rst" (the 2nd point), it states
that drivers shouldn't modify the shared parts of a cloned skb when
transmitting.

The "dev_queue_xmit_nit" function in "net/core/dev.c", which is called
when an skb is being sent, clones the skb and sents the clone to
AF_PACKET sockets. Because the LAPB drivers first remove a 1-byte
pseudo-header before handing over the skb to us, if we don't copy the
skb before prepending the LAPB header, the first byte of the packets
received on AF_PACKET sockets can be corrupted.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Xie He 
Acked-by: Martin Schiller 
Link: https://lore.kernel.org/r/20210201055706.415842-1-xie.he.0141@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

rxrpc: Fix deadlock around release of dst cached on udp tunnel

2021-02-10T08:25:27+00:00

[ Upstream commit 5399d52233c47905bbf97dcbaa2d7a9cc31670ba ]

AF_RXRPC sockets use UDP ports in encap mode.  This causes socket and dst
from an incoming packet to get stolen and attached to the UDP socket from
whence it is leaked when that socket is closed.

When a network namespace is removed, the wait for dst records to be cleaned
up happens before the cleanup of the rxrpc and UDP socket, meaning that the
wait never finishes.

Fix this by moving the rxrpc (and, by dependence, the afs) private
per-network namespace registrations to the device group rather than subsys
group.  This allows cached rxrpc local endpoints to be cleared and their
UDP sockets closed before we try waiting for the dst records.

The symptom is that lines looking like the following:

	unregister_netdevice: waiting for lo to become free

get emitted at regular intervals after running something like the
referenced syzbot test.

Thanks to Vadim for tracking this down and work out the fix.

Reported-by: syzbot+df400f2f24a1677cd7e0@syzkaller.appspotmail.com
Reported-by: Vadim Fedorenko 
Fixes: 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook")
Signed-off-by: David Howells 
Acked-by: Vadim Fedorenko 
Link: https://lore.kernel.org/r/161196443016.3868642.5577440140646403533.stgit@warthog.procyon.org.uk
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

mac80211: fix fast-rx encryption check

2021-02-07T14:35:48+00:00

[ Upstream commit 622d3b4e39381262da7b18ca1ed1311df227de86 ]

When using WEP, the default unicast key needs to be selected, instead of
the STA PTK.

Signed-off-by: Felix Fietkau 
Link: https://lore.kernel.org/r/20201218184718.93650-5-nbd@nbd.name
Signed-off-by: Johannes Berg 
Signed-off-by: Sasha Levin

net_sched: gen_estimator: support large ewma log

2021-02-07T14:35:47+00:00

commit dd5e073381f2ada3630f36be42833c6e9c78b75e upstream

syzbot report reminded us that very big ewma_log were supported in the past,
even if they made litle sense.

tc qdisc replace dev xxx root est 1sec 131072sec ...

While fixing the bug, also add boundary checks for ewma_log, in line
with range supported by iproute2.

UBSAN: shift-out-of-bounds in net/core/gen_estimator.c:83:38
shift exponent -1 is negative
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 ubsan_epilogue+0xb/0x5a lib/ubsan.c:148
 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x181 lib/ubsan.c:395
 est_timer.cold+0xbb/0x12d net/core/gen_estimator.c:83
 call_timer_fn+0x1a5/0x710 kernel/time/timer.c:1417
 expire_timers kernel/time/timer.c:1462 [inline]
 __run_timers.part.0+0x692/0xa80 kernel/time/timer.c:1731
 __run_timers kernel/time/timer.c:1712 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1744
 __do_softirq+0x2bc/0xa77 kernel/softirq.c:343
 asm_call_irq_on_stack+0xf/0x20
 
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:226 [inline]
 __irq_exit_rcu+0x17f/0x200 kernel/softirq.c:420
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:432
 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:79 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:169 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
RIP: 0010:acpi_idle_do_entry+0x1c9/0x250 drivers/acpi/processor_idle.c:516

Fixes: 1c0d32fde5bd ("net_sched: gen_estimator: complete rewrite of rate estimators")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Link: https://lore.kernel.org/r/20210114181929.1717985-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski 
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee 
Signed-off-by: Greg Kroah-Hartman

tcp: make TCP_USER_TIMEOUT accurate for zero window probes

2021-02-07T14:35:47+00:00

commit 344db93ae3ee69fc137bd6ed89a8ff1bf5b0db08 upstream.

The TCP_USER_TIMEOUT is checked by the 0-window probe timer. As the
timer has backoff with a max interval of about two minutes, the
actual timeout for TCP_USER_TIMEOUT can be off by up to two minutes.

In this patch the TCP_USER_TIMEOUT is made more accurate by taking it
into account when computing the timer value for the 0-window probes.

This patch is similar to and builds on top of the one that made
TCP_USER_TIMEOUT accurate for RTOs in commit b701a99e431d ("tcp: Add
tcp_clamp_rto_to_user_timeout() helper to improve accuracy").

Fixes: 9721e709fa68 ("tcp: simplify window probe aborting on USER_TIMEOUT")
Signed-off-by: Enke Chen 
Reviewed-by: Neal Cardwell 
Signed-off-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20210122191306.GA99540@localhost.localdomain
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

net: switchdev: don't set port_obj_info->handled true when -EOPNOTSUPP

2021-02-07T14:35:46+00:00

commit 20776b465c0c249f5e5b5b4fe077cd24ef1cda86 upstream.

It's not true that switchdev_port_obj_notify() only inspects the
->handled field of "struct switchdev_notifier_port_obj_info" if
call_switchdev_blocking_notifiers() returns 0 - there's a WARN_ON()
triggering for a non-zero return combined with ->handled not being
true. But the real problem here is that -EOPNOTSUPP is not being
properly handled.

The wrapper functions switchdev_handle_port_obj_add() et al change a
return value of -EOPNOTSUPP to 0, and the treatment of ->handled in
switchdev_port_obj_notify() seems to be designed to change that back
to -EOPNOTSUPP in case nobody actually acted on the notifier (i.e.,
everybody returned -EOPNOTSUPP).

Currently, as soon as some device down the stack passes the check_cb()
check, ->handled gets set to true, which means that
switchdev_port_obj_notify() cannot actually ever return -EOPNOTSUPP.

This, for example, means that the detection of hardware offload
support in the MRP code is broken: switchdev_port_obj_add() used by
br_mrp_switchdev_send_ring_test() always returns 0, so since the MRP
code thinks the generation of MRP test frames has been offloaded, no
such frames are actually put on the wire. Similarly,
br_mrp_switchdev_set_ring_role() also always returns 0, causing
mrp->ring_role_offloaded to be set to 1.

To fix this, continue to set ->handled true if any callback returns
success or any error distinct from -EOPNOTSUPP. But if all the
callbacks return -EOPNOTSUPP, make sure that ->handled stays false, so
the logic in switchdev_port_obj_notify() can propagate that
information.

Fixes: 9a9f26e8f7ea ("bridge: mrp: Connect MRP API with the switchdev API")
Fixes: f30f0601eb93 ("switchdev: Add helpers to aid traversal through lower devices")
Reviewed-by: Petr Machata 
Signed-off-by: Rasmus Villemoes 
Link: https://lore.kernel.org/r/20210125124116.102928-1-rasmus.villemoes@prevas.dk
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

tcp: fix TLP timer not set when CA_STATE changes from DISORDER to OPEN

2021-02-03T22:26:02+00:00

commit 62d9f1a6945ba69c125e548e72a36d203b30596e upstream.

Upon receiving a cumulative ACK that changes the congestion state from
Disorder to Open, the TLP timer is not set. If the sender is app-limited,
it can only wait for the RTO timer to expire and retransmit.

The reason for this is that the TLP timer is set before the congestion
state changes in tcp_ack(), so we delay the time point of calling
tcp_set_xmit_timer() until after tcp_fastretrans_alert() returns and
remove the FLAG_SET_XMIT_TIMER from ack_flag when the RACK reorder timer
is set.

This commit has two additional benefits:
1) Make sure to reset RTO according to RFC6298 when receiving ACK, to
avoid spurious RTO caused by RTO timer early expires.
2) Reduce the xmit timer reschedule once per ACK when the RACK reorder
timer is set.

Fixes: df92c8394e6e ("tcp: fix xmit timer to only be reset if data ACKed/SACKed")
Link: https://lore.kernel.org/netdev/1611311242-6675-1-git-send-email-yangpc@wangsu.com
Signed-off-by: Pengcheng Yang 
Acked-by: Neal Cardwell 
Acked-by: Yuchung Cheng 
Cc: Eric Dumazet 
Link: https://lore.kernel.org/r/1611464834-23030-1-git-send-email-yangpc@wangsu.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman