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David Howells e5ed4e08d8 rxrpc: Fix deadlock around release of dst cached on udp tunnel
[ 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 <vfedorenko@novek.ru>
Fixes: 5271953cad ("rxrpc: Use the UDP encap_rcv hook")
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vadim Fedorenko <vfedorenko@novek.ru>
Link: https://lore.kernel.org/r/161196443016.3868642.5577440140646403533.stgit@warthog.procyon.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-02-10 09:29:13 +01:00
arch arm64: dts: meson: switch TFLASH_VDD_EN pin to open drain on Odroid-C4 2021-02-10 09:29:13 +01:00
block blk-mq: test QUEUE_FLAG_HCTX_ACTIVE for sbitmap_shared in hctx_may_queue 2021-02-03 23:28:44 +01:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto crypto: xor - Fix divide error in do_xor_speed() 2021-01-27 11:54:52 +01:00
Documentation KVM: Documentation: Fix spec for KVM_CAP_ENABLE_CAP_VM 2021-02-03 23:28:43 +01:00
drivers r8169: work around RTL8125 UDP hw bug 2021-02-10 09:29:13 +01:00
fs rxrpc: Fix deadlock around release of dst cached on udp tunnel 2021-02-10 09:29:13 +01:00
include kthread: Extract KTHREAD_IS_PER_CPU 2021-02-07 15:37:17 +01:00
init rcu-tasks: Move RCU-tasks initialization to before early_initcall() 2021-01-19 18:27:28 +01:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel bpf, preload: Fix build when $(O) points to a relative path 2021-02-10 09:29:13 +01:00
lib iov_iter: fix the uaccess area in copy_compat_iovec_from_user 2021-01-27 11:55:09 +01:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm: fix a race on nr_swap_pages 2021-01-30 13:55:19 +01:00
net rxrpc: Fix deadlock around release of dst cached on udp tunnel 2021-02-10 09:29:13 +01:00
samples samples/bpf: Fix possible hang in xdpsock with multiple threads 2020-12-30 11:53:49 +01:00
scripts Revert "kconfig: remove 'kvmconfig' and 'xenconfig' shorthands" 2021-01-23 16:03:57 +01:00
security dump_common_audit_data(): fix racy accesses to ->d_name 2021-01-19 18:27:29 +01:00
sound ALSA: hda: Add Cometlake-R PCI ID 2021-02-07 15:37:15 +01:00
tools objtool: Don't fail the kernel build on fatal errors 2021-02-07 15:37:17 +01:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: Forbid the use of tagged userspace addresses for memslots 2021-02-03 23:28:41 +01:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-12-10 15:30:13 -08:00
Makefile Linux 5.10.14 2021-02-07 15:37:17 +01:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.