KCSAN: data-race in futex_wait_queue_me / get_task_mm (2)

Status: closed as invalid on 2020/06/18 14:24
Subsystems: kernel
[Documentation on labels]
First crash: 2426d, last: 2269d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in futex_wait_queue_me / get_task_mm mm 6 2 2462d 2473d 0/29 closed as invalid on 2019/11/19 13:54

Sample crash report:
==================================================================
BUG: KCSAN: data-race in futex_wait_queue_me / get_task_mm

write to 0xffff8880b28df0a4 of 4 bytes by task 10306 on cpu 1:
 freezer_count include/linux/freezer.h:121 [inline]
 freezable_schedule include/linux/freezer.h:173 [inline]
 futex_wait_queue_me+0x19e/0x290 kernel/futex.c:2631
 futex_wait+0x17e/0x3a0 kernel/futex.c:2737
 do_futex+0xe2/0x15b0 kernel/futex.c:3808
 __do_sys_futex kernel/futex.c:3869 [inline]
 __se_sys_futex kernel/futex.c:3837 [inline]
 __x64_sys_futex+0x2dc/0x410 kernel/futex.c:3837
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880b28df0a4 of 4 bytes by task 10310 on cpu 0:
 get_task_mm+0x4b/0x90 kernel/fork.c:1215
 do_task_stat+0xf5/0x1470 fs/proc/array.c:453
 proc_tgid_stat+0x39/0x50 fs/proc/array.c:632
 proc_single_show+0x8d/0x110 fs/proc/base.c:758
 seq_read+0x2ef/0x940 fs/seq_file.c:206
 do_loop_readv_writev fs/read_write.c:715 [inline]
 do_loop_readv_writev fs/read_write.c:702 [inline]
 do_iter_read+0x33f/0x3a0 fs/read_write.c:936
 vfs_readv+0x9c/0xf0 fs/read_write.c:1054
 do_preadv+0x129/0x1c0 fs/read_write.c:1146
 __do_sys_preadv fs/read_write.c:1196 [inline]
 __se_sys_preadv fs/read_write.c:1191 [inline]
 __x64_sys_preadv+0x5e/0x80 fs/read_write.c:1191
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10310 Comm: syz-executor.4 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/05/16 08:09 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 37bccd4e .config console log report ci2-upstream-kcsan-gce
2020/03/25 22:12 https://github.com/google/ktsan.git kcsan 40959e34d670 e8e6c7d2 .config console log report ci2-upstream-kcsan-gce
2020/02/16 16:20 https://github.com/google/ktsan.git kcsan b12d66a6c34f cf914200 .config console log report ci2-upstream-kcsan-gce
2020/02/15 01:55 https://github.com/google/ktsan.git kcsan b12d66a6c34f 5d7b90f1 .config console log report ci2-upstream-kcsan-gce
2020/01/30 13:37 https://github.com/google/ktsan.git kcsan 245a43005292 5ed23f9a .config console log report ci2-upstream-kcsan-gce
2020/01/13 02:17 https://github.com/google/ktsan.git kcsan 245a43005292 53faa9fe .config console log report ci2-upstream-kcsan-gce
2019/12/11 15:28 https://github.com/google/ktsan.git kcsan ef798c30ba4e 0d368675 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.