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KCSAN: data-race in dequeue_signal / ptrace_check_attach (3)

Status: auto-obsoleted due to no activity on 2023/04/16 11:35
Subsystems: kernel
[Documentation on labels]
First crash: 525d, last: 500d
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (6) kernel 1 276d 276d 0/27 auto-obsoleted due to no activity on 2023/11/16 03:30
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (7) kernel 13 112d 215d 0/27 auto-obsoleted due to no activity on 2024/04/27 21:52
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (5) kernel 3 315d 378d 0/27 auto-obsoleted due to no activity on 2023/10/08 11:58
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (2) kernel 1 570d 570d 0/27 auto-obsoleted due to no activity on 2023/02/02 07:54
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach kernel 1 673d 673d 0/27 auto-obsoleted due to no activity on 2022/10/15 10:03
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (4) kernel 2 439d 448d 0/27 auto-obsoleted due to no activity on 2023/06/06 04:16
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (8) kernel 2 57d 77d 0/27 auto-obsoleted due to no activity on 2024/06/22 14:38

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

read-write to 0xffff888115a97480 of 8 bytes by task 11529 on cpu 1:
 dequeue_signal+0x3ca/0x420 kernel/signal.c:688
 get_signal+0x349/0xfe0 kernel/signal.c:2739
 arch_do_signal_or_restart+0x89/0x2b0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop+0x6d/0xe0 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0x6a/0xa0 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888115a97480 of 8 bytes by task 11516 on cpu 0:
 ptrace_freeze_traced kernel/ptrace.c:199 [inline]
 ptrace_check_attach+0x7e/0x280 kernel/ptrace.c:266
 __do_sys_ptrace kernel/ptrace.c:1291 [inline]
 __se_sys_ptrace+0xd4/0x2a0 kernel/ptrace.c:1269
 __x64_sys_ptrace+0x55/0x60 kernel/ptrace.c:1269
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000000 -> 0x0000000008010000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11516 Comm: syz-executor.2 Not tainted 6.2.0-syzkaller-13115-gee3f96b16468-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/03/01 21:07 upstream ee3f96b16468 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
2023/02/14 16:48 upstream f6feea56f66d 93ae7e0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
2023/02/05 10:55 upstream 837c07cf68fe be607b78 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
* Struck through repros no longer work on HEAD.