KCSAN: data-race in get_signal / prepare_signal

Status: auto-closed as invalid on 2020/06/10 20:37
Subsystems: kernel
[Documentation on labels]
First crash: 2482d, last: 2326d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in get_signal / prepare_signal (2) kernel 6 1 2053d 2053d 0/29 auto-closed as invalid on 2021/02/04 02:28

Sample crash report:
==================================================================
BUG: KCSAN: data-race in get_signal / prepare_signal

write to 0xffff888059d220a4 of 4 bytes by task 18106 on cpu 0:
 get_signal+0x7a2/0x1290 kernel/signal.c:2714
 do_signal+0x2b/0x670 arch/x86/kernel/signal.c:813
 exit_to_usermode_loop+0x24a/0x2c0 arch/x86/entry/common.c:160
 prepare_exit_to_usermode+0x190/0x1c0 arch/x86/entry/common.c:195
 swapgs_restore_regs_and_return_to_usermode+0x0/0x40

read to 0xffff888059d220a4 of 4 bytes by task 7852 on cpu 1:
 sig_task_ignored kernel/signal.c:94 [inline]
 sig_ignored kernel/signal.c:119 [inline]
 prepare_signal+0x1f0/0x770 kernel/signal.c:956
 __send_signal+0x95/0x8a0 kernel/signal.c:1076
 send_signal+0x211/0x2a0 kernel/signal.c:1236
 do_send_sig_info+0x59/0xc0 kernel/signal.c:1285
 group_send_sig_info kernel/signal.c:1408 [inline]
 group_send_sig_info+0x8a/0x90 kernel/signal.c:1398
 kill_pid_info+0x4d/0x90 kernel/signal.c:1442
 kill_something_info+0x238/0x290 kernel/signal.c:1557
 __do_sys_kill kernel/signal.c:3640 [inline]
 __se_sys_kill kernel/signal.c:3634 [inline]
 __x64_sys_kill+0xef/0x120 kernel/signal.c:3634
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7852 Comm: syz-executor.4 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (17):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/04/01 20:31 https://github.com/google/ktsan.git kcsan 40959e34d670 a34e2c33 .config console log report ci2-upstream-kcsan-gce
2020/02/04 14:42 https://github.com/google/ktsan.git kcsan 245a43005292 93e5e335 .config console log report ci2-upstream-kcsan-gce
2020/01/25 08:53 https://github.com/google/ktsan.git kcsan 245a43005292 2e95ab33 .config console log report ci2-upstream-kcsan-gce
2020/01/14 17:18 https://github.com/google/ktsan.git kcsan 245a43005292 32881205 .config console log report ci2-upstream-kcsan-gce
2020/01/04 12:02 https://github.com/google/ktsan.git kcsan 245a43005292 68256974 .config console log report ci2-upstream-kcsan-gce
2019/12/25 11:08 https://github.com/google/ktsan.git kcsan 245a43005292 be5c2c81 .config console log report ci2-upstream-kcsan-gce
2019/12/20 02:09 https://github.com/google/ktsan.git kcsan 245a43005292 36650b4b .config console log report ci2-upstream-kcsan-gce
2019/12/17 10:47 https://github.com/google/ktsan.git kcsan 245a43005292 d13d7958 .config console log report ci2-upstream-kcsan-gce
2019/12/08 03:30 https://github.com/google/ktsan.git kcsan ef798c30ba4e 1508f453 .config console log report ci2-upstream-kcsan-gce
2019/12/07 05:37 https://github.com/google/ktsan.git kcsan ef798c30ba4e 85f26751 .config console log report ci2-upstream-kcsan-gce
2019/12/06 04:30 https://github.com/google/ktsan.git kcsan ef798c30ba4e 98b4ef2d .config console log report ci2-upstream-kcsan-gce
2019/12/01 00:36 https://github.com/google/ktsan.git kcsan ef798c30ba4e a76bf83f .config console log report ci2-upstream-kcsan-gce
2019/11/23 10:23 https://github.com/google/ktsan.git kcsan 5863cc791e4c 598ca6c8 .config console log report ci2-upstream-kcsan-gce
2019/11/17 16:36 https://github.com/google/ktsan.git kcsan 5863cc791e4c d5696d51 .config console log report ci2-upstream-kcsan-gce
2019/11/09 05:23 https://github.com/google/ktsan.git kcsan 94c006602e13 1e35461e .config console log report ci2-upstream-kcsan-gce
2019/11/04 20:32 https://github.com/google/ktsan.git kcsan 94c006602e13 18e12644 .config console log report ci2-upstream-kcsan-gce
2019/10/29 06:15 https://github.com/google/ktsan.git kcsan 05f2236801fe 5ea87a66 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.