0bdb5a7444
commit 2fe3d6d2053c57f2eae5e85ca1656d185ebbe4e8 upstream.
KCSAN reports a race in the CPU round robin function, which, as the
comment points out, is intentional:
BUG: KCSAN: data-race in wg_packet_send_staged_packets / wg_packet_send_staged_packets
read to 0xffff88811254eb28 of 4 bytes by task 3160 on cpu 1:
wg_cpumask_next_online drivers/net/wireguard/queueing.h:127 [inline]
wg_queue_enqueue_per_device_and_peer drivers/net/wireguard/queueing.h:173 [inline]
wg_packet_create_data drivers/net/wireguard/send.c:320 [inline]
wg_packet_send_staged_packets+0x60e/0xac0 drivers/net/wireguard/send.c:388
wg_packet_send_keepalive+0xe2/0x100 drivers/net/wireguard/send.c:239
wg_receive_handshake_packet drivers/net/wireguard/receive.c:186 [inline]
wg_packet_handshake_receive_worker+0x449/0x5f0 drivers/net/wireguard/receive.c:213
process_one_work kernel/workqueue.c:3248 [inline]
process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3329
worker_thread+0x526/0x720 kernel/workqueue.c:3409
kthread+0x1d1/0x210 kernel/kthread.c:389
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
write to 0xffff88811254eb28 of 4 bytes by task 3158 on cpu 0:
wg_cpumask_next_online drivers/net/wireguard/queueing.h:130 [inline]
wg_queue_enqueue_per_device_and_peer drivers/net/wireguard/queueing.h:173 [inline]
wg_packet_create_data drivers/net/wireguard/send.c:320 [inline]
wg_packet_send_staged_packets+0x6e5/0xac0 drivers/net/wireguard/send.c:388
wg_packet_send_keepalive+0xe2/0x100 drivers/net/wireguard/send.c:239
wg_receive_handshake_packet drivers/net/wireguard/receive.c:186 [inline]
wg_packet_handshake_receive_worker+0x449/0x5f0 drivers/net/wireguard/receive.c:213
process_one_work kernel/workqueue.c:3248 [inline]
process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3329
worker_thread+0x526/0x720 kernel/workqueue.c:3409
kthread+0x1d1/0x210 kernel/kthread.c:389
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
value changed: 0xffffffff -> 0x00000000
Mark this race as intentional by using READ/WRITE_ONCE().
Cc: stable@vger.kernel.org
Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://patch.msgid.link/20240704154517.1572127-4-Jason@zx2c4.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.