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KCSAN: data-race in dequeue_signal / ptrace_check_attach (4)

Status: auto-obsoleted due to no activity on 2023/06/06 04:16
Subsystems: kernel
[Documentation on labels]
First crash: 450d, last: 441d
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 278d 278d 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 114d 217d 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 317d 380d 0/27 auto-obsoleted due to no activity on 2023/10/08 11:58
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (3) kernel 3 503d 527d 0/27 auto-obsoleted due to no activity on 2023/04/16 11:35
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (2) kernel 1 572d 572d 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 675d 675d 0/27 auto-obsoleted due to no activity on 2022/10/15 10:03
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (8) kernel 2 59d 79d 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 0xffff88813cfbe500 of 8 bytes by task 23469 on cpu 0:
 dequeue_signal+0x3ca/0x420 kernel/signal.c:688
 get_signal+0x349/0xff0 kernel/signal.c:2754
 arch_do_signal_or_restart+0x89/0x2a0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88813cfbe500 of 8 bytes by task 23468 on cpu 1:
 ptrace_freeze_traced kernel/ptrace.c:200 [inline]
 ptrace_check_attach+0x7e/0x280 kernel/ptrace.c:267
 __do_sys_ptrace kernel/ptrace.c:1300 [inline]
 __se_sys_ptrace+0xd4/0x2a0 kernel/ptrace.c:1278
 __x64_sys_ptrace+0x55/0x60 kernel/ptrace.c:1278
 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: 1 PID: 23468 Comm: syz-executor.3 Not tainted 6.3.0-syzkaller-12378-gc8c655c34e33 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/05/02 04:11 upstream c8c655c34e33 62df2017 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
2023/04/23 09:08 upstream 622322f53c6d 2b32bd34 .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.