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KCSAN: data-race in prepare_signal / ptrace_attach

Status: auto-closed as invalid on 2020/07/29 00:33
Subsystems: kernel
[Documentation on labels]
First crash: 1860d, last: 1860d
Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in prepare_signal / ptrace_attach (5) kernel 6 2 1466d 1480d 0/29 auto-closed as invalid on 2021/08/26 15:59
upstream KCSAN: data-race in prepare_signal / ptrace_attach (12) kernel 6 1 216d 216d 0/29 auto-obsoleted due to no activity on 2025/02/17 10:01
upstream KCSAN: data-race in prepare_signal / ptrace_attach (6) kernel 6 1 1309d 1309d 0/29 auto-closed as invalid on 2022/01/30 21:35
upstream KCSAN: data-race in prepare_signal / ptrace_attach (13) kernel 6 2 84d 102d 0/29 auto-obsoleted due to no activity on 2025/06/30 03:24
upstream KCSAN: data-race in prepare_signal / ptrace_attach (2) kernel 6 3 1784d 1819d 0/29 auto-closed as invalid on 2020/10/13 05:51
upstream KCSAN: data-race in prepare_signal / ptrace_attach (9) kernel 6 1 631d 595d 0/29 auto-obsoleted due to no activity on 2023/12/25 00:07
upstream KCSAN: data-race in prepare_signal / ptrace_attach (11) kernel 6 1 474d 474d 0/29 auto-obsoleted due to no activity on 2024/05/14 10:05
upstream KCSAN: data-race in prepare_signal / ptrace_attach (7) kernel 6 1 1246d 1246d 0/29 auto-closed as invalid on 2022/04/03 14:09
upstream KCSAN: data-race in prepare_signal / ptrace_attach (8) kernel 6 1 1168d 1168d 0/29 auto-closed as invalid on 2022/06/20 14:20
upstream KCSAN: data-race in prepare_signal / ptrace_attach (10) kernel 6 2 520d 546d 0/29 auto-obsoleted due to no activity on 2024/03/29 18:16
upstream KCSAN: data-race in prepare_signal / ptrace_attach (4) kernel 6 1 1551d 1551d 0/29 auto-closed as invalid on 2021/06/03 07:49
upstream KCSAN: data-race in prepare_signal / ptrace_attach (3) kernel 6 2 1644d 1679d 0/29 auto-closed as invalid on 2021/03/01 09:38

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

write to 0xffff88811eb980a8 of 4 bytes by task 22907 on cpu 0:
 ptrace_attach+0x217/0x4a0 kernel/ptrace.c:413
 __do_sys_ptrace kernel/ptrace.c:1262 [inline]
 __se_sys_ptrace+0xc1/0x2d0 kernel/ptrace.c:1242
 __x64_sys_ptrace+0x51/0x60 kernel/ptrace.c:1242
 do_syscall_64+0x71/0x120 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811eb980a8 of 4 bytes by task 22911 on cpu 1:
 sig_ignored kernel/signal.c:116 [inline]
 prepare_signal+0x791/0xdb0 kernel/signal.c:961
 __send_signal+0x64/0x7d0 kernel/signal.c:1081
 send_signal+0x398/0x3e0 kernel/signal.c:1241
 do_send_sig_info+0x9b/0xe0 kernel/signal.c:1290
 do_send_specific kernel/signal.c:3780 [inline]
 do_tkill kernel/signal.c:3806 [inline]
 __do_sys_tkill kernel/signal.c:3841 [inline]
 __se_sys_tkill+0x12e/0x180 kernel/signal.c:3835
 __x64_sys_tkill+0x2d/0x40 kernel/signal.c:3835
 do_syscall_64+0x71/0x120 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 22911 Comm: syz-executor.2 Not tainted 5.8.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/24 00:30 upstream 3e08a95294a4 bbad15ae .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.