fs: dlm: don't call kernel_getpeername() in error_report()
authorAlexander Aring <aahringo@redhat.com>
Mon, 15 Nov 2021 13:57:05 +0000 (08:57 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 27 Jan 2022 09:53:48 +0000 (10:53 +0100)
commit55917db359763244fd76a4e4b0073ede949b2697
tree48ba2416274694cf5a50c2cebfd35283eb86fc3d
parent98923ebb034b8c405c5e9e216834021fe72d7875
fs: dlm: don't call kernel_getpeername() in error_report()

[ Upstream commit 4c3d90570bcc2b338f70f61f01110268e281ca3c ]

In some cases kernel_getpeername() will held the socket lock which is
already held when the socket layer calls error_report() callback. Since
commit 9dfc685e0262 ("inet: remove races in inet{6}_getname()") this
problem becomes more likely because the socket lock will be held always.
You will see something like:

bob9-u5 login: [  562.316860] BUG: spinlock recursion on CPU#7, swapper/7/0
[  562.318562]  lock: 0xffff8f2284720088, .magic: dead4ead, .owner: swapper/7/0, .owner_cpu: 7
[  562.319522] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 5.15.0+ #135
[  562.320346] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014
[  562.321277] Call Trace:
[  562.321529]  <IRQ>
[  562.321734]  dump_stack_lvl+0x33/0x42
[  562.322282]  do_raw_spin_lock+0x8b/0xc0
[  562.322674]  lock_sock_nested+0x1e/0x50
[  562.323057]  inet_getname+0x39/0x110
[  562.323425]  ? sock_def_readable+0x80/0x80
[  562.323838]  lowcomms_error_report+0x63/0x260 [dlm]
[  562.324338]  ? wait_for_completion_interruptible_timeout+0xd2/0x120
[  562.324949]  ? lock_timer_base+0x67/0x80
[  562.325330]  ? do_raw_spin_unlock+0x49/0xc0
[  562.325735]  ? _raw_spin_unlock_irqrestore+0x1e/0x40
[  562.326218]  ? del_timer+0x54/0x80
[  562.326549]  sk_error_report+0x12/0x70
[  562.326919]  tcp_validate_incoming+0x3c8/0x530
[  562.327347]  ? kvm_clock_read+0x14/0x30
[  562.327718]  ? ktime_get+0x3b/0xa0
[  562.328055]  tcp_rcv_established+0x121/0x660
[  562.328466]  tcp_v4_do_rcv+0x132/0x260
[  562.328835]  tcp_v4_rcv+0xcea/0xe20
[  562.329173]  ip_protocol_deliver_rcu+0x35/0x1f0
[  562.329615]  ip_local_deliver_finish+0x54/0x60
[  562.330050]  ip_local_deliver+0xf7/0x110
[  562.330431]  ? inet_rtm_getroute+0x211/0x840
[  562.330848]  ? ip_protocol_deliver_rcu+0x1f0/0x1f0
[  562.331310]  ip_rcv+0xe1/0xf0
[  562.331603]  ? ip_local_deliver+0x110/0x110
[  562.332011]  __netif_receive_skb_core+0x46a/0x1040
[  562.332476]  ? inet_gro_receive+0x263/0x2e0
[  562.332885]  __netif_receive_skb_list_core+0x13b/0x2c0
[  562.333383]  netif_receive_skb_list_internal+0x1c8/0x2f0
[  562.333896]  ? update_load_avg+0x7e/0x5e0
[  562.334285]  gro_normal_list.part.149+0x19/0x40
[  562.334722]  napi_complete_done+0x67/0x160
[  562.335134]  virtnet_poll+0x2ad/0x408 [virtio_net]
[  562.335644]  __napi_poll+0x28/0x140
[  562.336012]  net_rx_action+0x23d/0x300
[  562.336414]  __do_softirq+0xf2/0x2ea
[  562.336803]  irq_exit_rcu+0xc1/0xf0
[  562.337173]  common_interrupt+0xb9/0xd0

It is and was always forbidden to call kernel_getpeername() in context
of error_report(). To get rid of the problem we access the destination
address for the peer over the socket structure. While on it we fix to
print out the destination port of the inet socket.

Fixes: 1a31833d085a ("DLM: Replace nodeid_to_addr with kernel_getpeername")
Reported-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
fs/dlm/lowcomms.c