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KCSAN: data-race in get_signal / ptrace_check_attach

Status: closed as invalid on 2020/06/18 14:24
Subsystems: kasan
[Documentation on labels]
First crash: 2239d, last: 2044d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in get_signal / ptrace_check_attach (2) kernel 6 194 1690d 1945d 0/29 auto-closed as invalid on 2021/07/07 23:21

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

write to 0xffff8880b2ff24c8 of 8 bytes by task 11005 on cpu 0:
 ptrace_signal kernel/signal.c:2489 [inline]
 get_signal+0xbe8/0x1290 kernel/signal.c:2635
 do_signal+0x2b/0x840 arch/x86/kernel/signal.c:784
 exit_to_usermode_loop+0x24a/0x2c0 arch/x86/entry/common.c:161
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x38b/0x3b0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880b2ff24c8 of 8 bytes by task 11006 on cpu 1:
 ptrace_freeze_traced kernel/ptrace.c:178 [inline]
 ptrace_check_attach+0xf9/0x260 kernel/ptrace.c:247
 __do_sys_ptrace kernel/ptrace.c:1272 [inline]
 __se_sys_ptrace kernel/ptrace.c:1242 [inline]
 __x64_sys_ptrace+0x102/0x270 kernel/ptrace.c:1242
 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: 1 PID: 11006 Comm: syz-executor.5 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 11006 Comm: syz-executor.5 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x11d/0x187 lib/dump_stack.c:118
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0x1a kernel/kcsan/report.c:626
 kcsan_setup_watchpoint+0x3fb/0x440 kernel/kcsan/core.c:519
 ptrace_freeze_traced kernel/ptrace.c:178 [inline]
 ptrace_check_attach+0xf9/0x260 kernel/ptrace.c:247
 __do_sys_ptrace kernel/ptrace.c:1272 [inline]
 __se_sys_ptrace kernel/ptrace.c:1242 [inline]
 __x64_sys_ptrace+0x102/0x270 kernel/ptrace.c:1242
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45ca69
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f9a94f97c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000065
RAX: ffffffffffffffda RBX: 00000000004fb240 RCX: 000000000045ca69
RDX: 0000000000000000 RSI: 0000000000000052 RDI: 0000000000000007
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000881 R14: 00000000004cb6ad R15: 00007f9a94f986d4
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (23):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/13 22:44 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 dbce178a .config console log report ci2-upstream-kcsan-gce
2020/06/11 22:49 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 1beaee21 .config console log report ci2-upstream-kcsan-gce
2020/06/11 09:49 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 3ab7a05a .config console log report ci2-upstream-kcsan-gce
2020/06/08 15:16 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 7604bb03 .config console log report ci2-upstream-kcsan-gce
2020/05/26 19:42 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 9072c126 .config console log report ci2-upstream-kcsan-gce
2020/05/26 19:32 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 9072c126 .config console log report ci2-upstream-kcsan-gce
2020/05/23 03:33 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 4afdfa20 .config console log report ci2-upstream-kcsan-gce
2020/05/19 17:50 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 6d882fd2 .config console log report ci2-upstream-kcsan-gce
2020/05/19 05:15 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 684d3606 .config console log report ci2-upstream-kcsan-gce
2020/05/15 03:02 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2d572622 .config console log report ci2-upstream-kcsan-gce
2020/05/13 22:38 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a885920d .config console log report ci2-upstream-kcsan-gce
2020/05/07 03:25 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 4618eb2d .config console log report ci2-upstream-kcsan-gce
2020/05/03 06:56 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 5457883a .config console log report ci2-upstream-kcsan-gce
2020/04/26 21:29 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 0ce7569e .config console log report ci2-upstream-kcsan-gce
2020/04/26 01:53 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 b8bb8e5f .config console log report ci2-upstream-kcsan-gce
2020/04/25 05:28 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 03d97a1b .config console log report ci2-upstream-kcsan-gce
2020/04/23 04:23 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2e44d63e .config console log report ci2-upstream-kcsan-gce
2020/04/21 21:21 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 f20434a8 .config console log report ci2-upstream-kcsan-gce
2020/04/20 16:02 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 347a5dc3 .config console log report ci2-upstream-kcsan-gce
2020/04/19 00:13 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 365fba24 .config console log report ci2-upstream-kcsan-gce
2020/04/16 13:49 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 c743fcb3 .config console log report ci2-upstream-kcsan-gce
2020/02/07 12:55 https://github.com/google/ktsan.git kcsan 245a43005292 06150bf1 .config console log report ci2-upstream-kcsan-gce
2019/12/02 09:02 https://github.com/google/ktsan.git kcsan ef798c30ba4e f879db37 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.