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KCSAN: data-race in enqueue_timer / mod_timer

Status: closed as invalid on 2019/11/19 13:44
Subsystems: block
[Documentation on labels]
First crash: 1625d, last: 1605d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in enqueue_timer / mod_timer (2) net 2 1530d 1588d 0/26 auto-closed as invalid on 2020/03/29 15:30

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

write to 0xffff888129ddf6d0 of 8 bytes by task 1838 on cpu 1:
 hlist_add_head include/linux/list.h:789 [inline]
 enqueue_timer+0x9c/0x210 kernel/time/timer.c:540
 __internal_add_timer+0x4f/0x60 kernel/time/timer.c:553
 internal_add_timer kernel/time/timer.c:595 [inline]
 __mod_timer kernel/time/timer.c:1053 [inline]
 mod_timer+0x303/0x7a0 kernel/time/timer.c:1100
 blk_add_timer+0x1c6/0x1d0 block/blk-timeout.c:148
 blk_mq_start_request+0xb7/0x370 block/blk-mq.c:693
 loop_queue_rq+0x64/0x2b0 drivers/block/loop.c:1898
 blk_mq_dispatch_rq_list+0xbe9/0xe40 block/blk-mq.c:1273
 blk_mq_do_dispatch_sched+0x11d/0x260 block/blk-mq-sched.c:115
 blk_mq_sched_dispatch_requests+0x2b4/0x380 block/blk-mq-sched.c:211
 __blk_mq_run_hw_queue+0xb7/0x160 block/blk-mq.c:1403
 __blk_mq_delay_run_hw_queue+0x31b/0x3a0 block/blk-mq.c:1471
 blk_mq_run_hw_queue+0x103/0x1c0 block/blk-mq.c:1508
 blk_mq_sched_insert_requests+0x1ca/0x2e0 block/blk-mq-sched.c:444
 blk_mq_flush_plug_list+0x572/0x6c0 block/blk-mq.c:1772
 blk_flush_plug_list+0x271/0x2a0 block/blk-core.c:1766
 blk_finish_plug block/blk-core.c:1783 [inline]
 blk_finish_plug+0x60/0x84 block/blk-core.c:1779
 read_pages+0xbc/0x2d0 mm/readahead.c:142
 __do_page_cache_readahead+0x353/0x390 mm/readahead.c:212
 force_page_cache_readahead+0x13a/0x1f0 mm/readahead.c:243
 page_cache_sync_readahead+0x1cf/0x1e0 mm/readahead.c:522
 generic_file_buffered_read mm/filemap.c:2051 [inline]
 generic_file_read_iter+0xeb6/0x1440 mm/filemap.c:2324
 blkdev_read_iter+0xb2/0xe0 fs/block_dev.c:2010
 call_read_iter include/linux/fs.h:1889 [inline]
 new_sync_read+0x389/0x4f0 fs/read_write.c:414
 __vfs_read+0xb1/0xc0 fs/read_write.c:427
 vfs_read fs/read_write.c:461 [inline]
 vfs_read+0x143/0x2c0 fs/read_write.c:446
 ksys_read+0xd5/0x1b0 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x4c/0x60 fs/read_write.c:595
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888129ddf6d0 of 8 bytes by task 2492 on cpu 0:
 __mod_timer kernel/time/timer.c:963 [inline]
 mod_timer+0x59/0x7a0 kernel/time/timer.c:1100
 blk_add_timer+0x1c6/0x1d0 block/blk-timeout.c:148
 blk_mq_start_request+0xb7/0x370 block/blk-mq.c:693
 loop_queue_rq+0x64/0x2b0 drivers/block/loop.c:1898
 blk_mq_dispatch_rq_list+0xbe9/0xe40 block/blk-mq.c:1273
 blk_mq_do_dispatch_sched+0x11d/0x260 block/blk-mq-sched.c:115
 blk_mq_sched_dispatch_requests+0x2b4/0x380 block/blk-mq-sched.c:211
 __blk_mq_run_hw_queue+0xb7/0x160 block/blk-mq.c:1403
 blk_mq_run_work_fn+0x57/0x70 block/blk-mq.c:1636
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2492 Comm: kworker/0:1H Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: kblockd blk_mq_run_work_fn
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/11/05 13:04 https://github.com/google/ktsan.git kcsan 94c006602e13 0f3ec414 .config console log report ci2-upstream-kcsan-gce
2019/10/16 19:32 https://github.com/google/ktsan.git kcsan a6311db074d9 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.