syzbot


KCSAN: data-race in prepare_signal / ptrace_attach (11)

Status: auto-obsoleted due to no activity on 2024/05/14 10:05
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+142d9ec803fd1b652b28@syzkaller.appspotmail.com
First crash: 39d, last: 39d
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 1031d 1045d 0/26 auto-closed as invalid on 2021/08/26 15:59
upstream KCSAN: data-race in prepare_signal / ptrace_attach kernel 1 1424d 1424d 0/26 auto-closed as invalid on 2020/07/29 00:33
upstream KCSAN: data-race in prepare_signal / ptrace_attach (6) kernel 1 873d 873d 0/26 auto-closed as invalid on 2022/01/30 21:35
upstream KCSAN: data-race in prepare_signal / ptrace_attach (2) kernel 3 1348d 1383d 0/26 auto-closed as invalid on 2020/10/13 05:51
upstream KCSAN: data-race in prepare_signal / ptrace_attach (9) kernel 1 196d 159d 0/26 auto-obsoleted due to no activity on 2023/12/25 00:07
upstream KCSAN: data-race in prepare_signal / ptrace_attach (7) kernel 1 811d 811d 0/26 auto-closed as invalid on 2022/04/03 14:09
upstream KCSAN: data-race in prepare_signal / ptrace_attach (8) kernel 1 733d 733d 0/26 auto-closed as invalid on 2022/06/20 14:20
upstream KCSAN: data-race in prepare_signal / ptrace_attach (10) kernel 2 84d 110d 0/26 auto-obsoleted due to no activity on 2024/03/29 18:16
upstream KCSAN: data-race in prepare_signal / ptrace_attach (4) kernel 1 1115d 1115d 0/26 auto-closed as invalid on 2021/06/03 07:49
upstream KCSAN: data-race in prepare_signal / ptrace_attach (3) kernel 2 1209d 1243d 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 0xffff888150222130 of 4 bytes by task 23853 on cpu 0:
 ptrace_attach+0x321/0x590 kernel/ptrace.c:462
 __do_sys_ptrace kernel/ptrace.c:1276 [inline]
 __se_sys_ptrace+0x149/0x2b0 kernel/ptrace.c:1258
 __x64_sys_ptrace+0x55/0x70 kernel/ptrace.c:1258
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

read to 0xffff888150222130 of 4 bytes by task 23848 on cpu 1:
 prepare_signal+0x258/0x670 kernel/signal.c:934
 __send_signal_locked+0x2f/0x700 kernel/signal.c:1085
 send_signal_locked+0x28f/0x3a0 kernel/signal.c:1248
 do_send_sig_info+0x9f/0xf0 kernel/signal.c:1301
 group_send_sig_info kernel/signal.c:1453 [inline]
 kill_pid_info_type+0x85/0xd0 kernel/signal.c:1493
 kill_pid_info kernel/signal.c:1507 [inline]
 kill_proc_info kernel/signal.c:1514 [inline]
 do_rt_sigqueueinfo kernel/signal.c:4063 [inline]
 __do_sys_rt_sigqueueinfo kernel/signal.c:4079 [inline]
 __se_sys_rt_sigqueueinfo+0xcd/0x110 kernel/signal.c:4072
 __x64_sys_rt_sigqueueinfo+0x43/0x50 kernel/signal.c:4072
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23848 Comm: syz-executor.2 Tainted: G        W          6.9.0-rc3-syzkaller-00011-g20cb38a7af88 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/09 10:04 upstream 20cb38a7af88 f3234354 .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.