syzbot


KCSAN: data-race in prepare_signal / ptrace_attach (10)

Status: auto-obsoleted due to no activity on 2024/03/29 18:16
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+08ca189817ae7e7c8a29@syzkaller.appspotmail.com
First crash: 80d, last: 55d
Similar bugs (10)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in prepare_signal / ptrace_attach (5) kernel 2 1001d 1015d 0/26 auto-closed as invalid on 2021/08/26 15:59
upstream KCSAN: data-race in prepare_signal / ptrace_attach kernel 1 1394d 1394d 0/26 auto-closed as invalid on 2020/07/29 00:33
upstream KCSAN: data-race in prepare_signal / ptrace_attach (6) kernel 1 844d 844d 0/26 auto-closed as invalid on 2022/01/30 21:35
upstream KCSAN: data-race in prepare_signal / ptrace_attach (2) kernel 3 1318d 1353d 0/26 auto-closed as invalid on 2020/10/13 05:51
upstream KCSAN: data-race in prepare_signal / ptrace_attach (9) kernel 1 166d 130d 0/26 auto-obsoleted due to no activity on 2023/12/25 00:07
upstream KCSAN: data-race in prepare_signal / ptrace_attach (11) kernel 1 9d14h 9d14h 0/26 moderation: reported on 2024/04/09 10:05
upstream KCSAN: data-race in prepare_signal / ptrace_attach (7) kernel 1 781d 781d 0/26 auto-closed as invalid on 2022/04/03 14:09
upstream KCSAN: data-race in prepare_signal / ptrace_attach (8) kernel 1 703d 703d 0/26 auto-closed as invalid on 2022/06/20 14:20
upstream KCSAN: data-race in prepare_signal / ptrace_attach (4) kernel 1 1085d 1085d 0/26 auto-closed as invalid on 2021/06/03 07:49
upstream KCSAN: data-race in prepare_signal / ptrace_attach (3) kernel 2 1179d 1214d 0/26 auto-closed as invalid on 2021/03/01 09:38

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

write to 0xffff88813d55b0f0 of 4 bytes by task 8773 on cpu 1:
 ptrace_attach+0x31c/0x590 kernel/ptrace.c:459
 __do_sys_ptrace kernel/ptrace.c:1279 [inline]
 __se_sys_ptrace+0x149/0x2a0 kernel/ptrace.c:1261
 __x64_sys_ptrace+0x55/0x60 kernel/ptrace.c:1261
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88813d55b0f0 of 4 bytes by task 8776 on cpu 0:
 prepare_signal+0x258/0x660 kernel/signal.c:933
 __send_signal_locked+0x2f/0x700 kernel/signal.c:1084
 send_signal_locked+0x28d/0x3a0 kernel/signal.c:1247
 do_send_sig_info+0x9f/0xf0 kernel/signal.c:1300
 do_send_specific+0xc4/0x100 kernel/signal.c:3949
 do_tkill kernel/signal.c:3975 [inline]
 __do_sys_tgkill kernel/signal.c:3994 [inline]
 __se_sys_tgkill kernel/signal.c:3988 [inline]
 __x64_sys_tgkill+0x115/0x150 kernel/signal.c:3988
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00000000 -> 0x00010001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8776 Comm: syz-executor.1 Tainted: G        W          6.8.0-rc5-syzkaller-00163-gffd2cb6b718e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/23 18:15 upstream ffd2cb6b718e 8d446f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in prepare_signal / ptrace_attach
2024/01/29 04:47 upstream 4854cf9c61d0 cc4a4020 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in prepare_signal / ptrace_attach
* Struck through repros no longer work on HEAD.