================================================================== BUG: KCSAN: data-race in __mod_timer / timer_clear_idle write to 0xffff88812c11cb24 of 1 bytes by task 0 on cpu 1: timer_clear_idle+0x2e/0x40 kernel/time/timer.c:1675 tick_nohz_idle_retain_tick+0x3e/0x40 kernel/time/tick-sched.c:1004 cpuidle_idle_call kernel/sched/idle.c:210 [inline] do_idle+0x287/0x310 kernel/sched/idle.c:276 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:372 start_secondary+0xe3/0x110 arch/x86/kernel/smpboot.c:268 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 read to 0xffff88812c11cb24 of 1 bytes by task 8651 on cpu 0: forward_timer_base kernel/time/timer.c:891 [inline] __mod_timer+0xb87/0xf00 kernel/time/timer.c:983 mod_timer+0x1b/0x20 kernel/time/timer.c:1100 sk_reset_timer+0x1f/0xa0 net/core/sock.c:2953 inet_csk_reset_xmit_timer include/net/inet_connection_sock.h:234 [inline] tcp_reset_xmit_timer include/net/tcp.h:1306 [inline] tcp_rearm_rto+0x204/0x210 net/ipv4/tcp_input.c:2999 tcp_event_new_data_sent net/ipv4/tcp_output.c:81 [inline] tcp_write_xmit+0x1bee/0x3f40 net/ipv4/tcp_output.c:2524 __tcp_push_pending_frames+0x68/0x1c0 net/ipv4/tcp_output.c:2692 tcp_push+0x2da/0x2f0 net/ipv4/tcp.c:733 tcp_sendmsg_locked+0x1bf9/0x2200 net/ipv4/tcp.c:1411 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1441 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:814 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] sock_write_iter+0x1a1/0x200 net/socket.c:999 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write fs/read_write.c:484 [inline] __vfs_write+0x2d8/0x340 fs/read_write.c:497 vfs_write+0x19b/0x350 fs/read_write.c:559 ksys_write+0xce/0x180 fs/read_write.c:612 __do_sys_write fs/read_write.c:624 [inline] __se_sys_write fs/read_write.c:621 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:621 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 8651 Comm: syz-fuzzer Not tainted 5.8.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================