195374d893
syzbot reported a data-race while accessing nh->nh_saddr_genid [1] Add annotations, but leave the code lazy as intended. [1] BUG: KCSAN: data-race in fib_select_path / fib_select_path write to 0xffff8881387166f0 of 4 bytes by task 6778 on cpu 1: fib_info_update_nhc_saddr net/ipv4/fib_semantics.c:1334 [inline] fib_result_prefsrc net/ipv4/fib_semantics.c:1354 [inline] fib_select_path+0x292/0x330 net/ipv4/fib_semantics.c:2269 ip_route_output_key_hash_rcu+0x659/0x12c0 net/ipv4/route.c:2810 ip_route_output_key_hash net/ipv4/route.c:2644 [inline] __ip_route_output_key include/net/route.h:134 [inline] ip_route_output_flow+0xa6/0x150 net/ipv4/route.c:2872 send4+0x1f5/0x520 drivers/net/wireguard/socket.c:61 wg_socket_send_skb_to_peer+0x94/0x130 drivers/net/wireguard/socket.c:175 wg_socket_send_buffer_to_peer+0xd6/0x100 drivers/net/wireguard/socket.c:200 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline] wg_packet_handshake_send_worker+0x10c/0x150 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703 worker_thread+0x525/0x730 kernel/workqueue.c:2784 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 read to 0xffff8881387166f0 of 4 bytes by task 6759 on cpu 0: fib_result_prefsrc net/ipv4/fib_semantics.c:1350 [inline] fib_select_path+0x1cb/0x330 net/ipv4/fib_semantics.c:2269 ip_route_output_key_hash_rcu+0x659/0x12c0 net/ipv4/route.c:2810 ip_route_output_key_hash net/ipv4/route.c:2644 [inline] __ip_route_output_key include/net/route.h:134 [inline] ip_route_output_flow+0xa6/0x150 net/ipv4/route.c:2872 send4+0x1f5/0x520 drivers/net/wireguard/socket.c:61 wg_socket_send_skb_to_peer+0x94/0x130 drivers/net/wireguard/socket.c:175 wg_socket_send_buffer_to_peer+0xd6/0x100 drivers/net/wireguard/socket.c:200 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline] wg_packet_handshake_send_worker+0x10c/0x150 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703 worker_thread+0x525/0x730 kernel/workqueue.c:2784 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 value changed: 0x959d3217 -> 0x959d3218 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 6759 Comm: kworker/u4:15 Not tainted 6.6.0-rc4-syzkaller-00029-gcbf3a2cb156a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker Fixes: 436c3b66ec98 ("ipv4: Invalidate nexthop cache nh_saddr more correctly.") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20231017192304.82626-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.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.