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KCSAN: data-race in mod_timer / timer_clear_idle

Status: closed as invalid on 2019/10/15 15:50
Subsystems: net
[Documentation on labels]
First crash: 2025d, last: 2015d
▶ ▼ Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in mod_timer / timer_clear_idle (2) kernel 40 1980d 2012d 0/28 closed as invalid on 2019/11/19 14:04
upstream KCSAN: data-race in mod_timer / timer_clear_idle (3) kernel 246 1768d 1926d 0/28 auto-closed as invalid on 2020/07/23 13:02

Sample crash report:
==================================================================
BUG: KCSAN: data-race in mod_timer / timer_clear_idle

read to 0xffff88812be1b6e4 of 1 bytes by task 7340 on cpu 1:
 forward_timer_base kernel/time/timer.c:888 [inline]
 __mod_timer kernel/time/timer.c:979 [inline]
 mod_timer+0x50d/0x7a0 kernel/time/timer.c:1096
 sk_reset_timer+0x2d/0x70 net/core/sock.c:2830
 inet_csk_reset_xmit_timer include/net/inet_connection_sock.h:234 [inline]
 tcp_reset_xmit_timer include/net/tcp.h:1269 [inline]
 tcp_rearm_rto.part.0+0x190/0x240 net/ipv4/tcp_input.c:3009
 tcp_rearm_rto+0x4f/0x60 net/ipv4/tcp_input.c:3012
 tcp_event_new_data_sent+0x1bb/0x1c0 net/ipv4/tcp_output.c:77
 tcp_write_xmit+0xa16/0x3080 net/ipv4/tcp_output.c:2436
 __tcp_push_pending_frames+0x7b/0x1d0 net/ipv4/tcp_output.c:2605
 tcp_push+0x1e9/0x3d0 net/ipv4/tcp.c:724
 tcp_sendmsg_locked+0x1d1b/0x1ef0 net/ipv4/tcp.c:1402
 tcp_sendmsg+0x39/0x60 net/ipv4/tcp.c:1433
 inet_sendmsg+0x6d/0x90 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 sock_write_iter+0x16b/0x210 net/socket.c:989
 call_write_iter include/linux/fs.h:1870 [inline]
 new_sync_write+0x388/0x4a0 fs/read_write.c:483

write to 0xffff88812be1b6e4 of 1 bytes by task 0 on cpu 0:
 timer_clear_idle+0x42/0x50 kernel/time/timer.c:1590
 tick_nohz_restart_sched_tick kernel/time/tick-sched.c:836 [inline]
 __tick_nohz_idle_restart_tick+0x36/0x1b0 kernel/time/tick-sched.c:1137
 tick_nohz_idle_exit+0x1af/0x1e0 kernel/time/tick-sched.c:1178
 do_idle+0xb0/0x2c0 kernel/sched/idle.c:276
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354
 rest_init+0xec/0xf6 init/main.c:452
 arch_call_rest_init+0x17/0x37
 start_kernel+0x83e/0x864 init/main.c:787
 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:472
 x86_64_start_kernel+0x72/0x76 arch/x86/kernel/head64.c:453
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (23):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/15 12:16 https://github.com/google/ktsan.git kcsan 81f95ec7998e b5268b89 .config console log report ci2-upstream-kcsan-gce
2019/10/14 10:37 https://github.com/google/ktsan.git kcsan d724f94f63de a6aef847 .config console log report ci2-upstream-kcsan-gce
2019/10/12 09:19 https://github.com/google/ktsan.git kcsan d724f94f63de 426631dd .config console log report ci2-upstream-kcsan-gce
2019/10/12 08:28 https://github.com/google/ktsan.git kcsan d724f94f63de 426631dd .config console log report ci2-upstream-kcsan-gce
2019/10/11 21:50 https://github.com/google/ktsan.git kcsan d724f94f63de 426631dd .config console log report ci2-upstream-kcsan-gce
2019/10/11 08:58 https://github.com/google/ktsan.git kcsan d724f94f63de 1a3bad90 .config console log report ci2-upstream-kcsan-gce
2019/10/11 08:55 https://github.com/google/ktsan.git kcsan d724f94f63de 1a3bad90 .config console log report ci2-upstream-kcsan-gce
2019/10/11 00:05 https://github.com/google/ktsan.git kcsan d724f94f63de 1a3bad90 .config console log report ci2-upstream-kcsan-gce
2019/10/10 12:09 https://github.com/google/ktsan.git kcsan d724f94f63de d52eff28 .config console log report ci2-upstream-kcsan-gce
2019/10/10 10:39 https://github.com/google/ktsan.git kcsan d724f94f63de d52eff28 .config console log report ci2-upstream-kcsan-gce
2019/10/09 20:18 https://github.com/google/ktsan.git kcsan d724f94f63de c4b9981b .config console log report ci2-upstream-kcsan-gce
2019/10/09 19:53 https://github.com/google/ktsan.git kcsan d724f94f63de c4b9981b .config console log report ci2-upstream-kcsan-gce
2019/10/09 11:21 https://github.com/google/ktsan.git kcsan d724f94f63de 312c6a5a .config console log report ci2-upstream-kcsan-gce
2019/10/09 07:24 https://github.com/google/ktsan.git kcsan d724f94f63de 312c6a5a .config console log report ci2-upstream-kcsan-gce
2019/10/09 06:21 https://github.com/google/ktsan.git kcsan d724f94f63de b1ebbfef .config console log report ci2-upstream-kcsan-gce
2019/10/09 05:55 https://github.com/google/ktsan.git kcsan d724f94f63de b1ebbfef .config console log report ci2-upstream-kcsan-gce
2019/10/08 18:45 https://github.com/google/ktsan.git kcsan d724f94f63de b1ebbfef .config console log report ci2-upstream-kcsan-gce
2019/10/08 11:20 https://github.com/google/ktsan.git kcsan c1c7521f03c7 64612bfd .config console log report ci2-upstream-kcsan-gce
2019/10/08 02:33 https://github.com/google/ktsan.git kcsan c1c7521f03c7 28ac6e64 .config console log report ci2-upstream-kcsan-gce
2019/10/07 17:42 https://github.com/google/ktsan.git kcsan c1c7521f03c7 28ac6e64 .config console log report ci2-upstream-kcsan-gce
2019/10/07 17:15 https://github.com/google/ktsan.git kcsan c1c7521f03c7 28ac6e64 .config console log report ci2-upstream-kcsan-gce
2019/10/06 00:45 https://github.com/google/ktsan.git kcsan c1c7521f03c7 f3f7d9c8 .config console log report ci2-upstream-kcsan-gce
2019/10/04 23:09 https://github.com/google/ktsan.git kcsan b4bd934316dc c86336cf .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.