syzbot


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

Status: auto-closed as invalid on 2020/12/21 11:57
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+977ff1103c717b107726@syzkaller.appspotmail.com
First crash: 1241d, last: 1241d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ptrace_check_attach / zap_other_threads kernel 1 1335d 1335d 0/26 auto-closed as invalid on 2020/09/05 20:28
upstream KCSAN: data-race in ptrace_check_attach / zap_other_threads (2) kernel 1 1300d 1300d 0/26 auto-closed as invalid on 2020/10/10 22:50
upstream KCSAN: data-race in ptrace_check_attach / zap_other_threads (5) kernel 9 1032d 1067d 0/26 auto-closed as invalid on 2021/07/05 18:29
upstream KCSAN: data-race in ptrace_check_attach / zap_other_threads (4) kernel 1 1129d 1129d 0/26 auto-closed as invalid on 2021/03/30 13:55

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

read-write to 0xffff888134b5c4a8 of 8 bytes by task 14110 on cpu 1:
 task_clear_jobctl_pending kernel/signal.c:344 [inline]
 zap_other_threads+0x90/0x1d0 kernel/signal.c:1356
 do_group_exit+0x140/0x170 kernel/exit.c:898
 __do_sys_exit_group+0xb/0x10 kernel/exit.c:914
 __se_sys_exit_group+0x5/0x10 kernel/exit.c:912
 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:912
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888134b5c4a8 of 8 bytes by task 14119 on cpu 0:
 ptrace_freeze_traced kernel/ptrace.c:178 [inline]
 ptrace_check_attach+0xdc/0x230 kernel/ptrace.c:247
 __do_sys_ptrace kernel/ptrace.c:1272 [inline]
 __se_sys_ptrace+0xdb/0x2e0 kernel/ptrace.c:1242
 __x64_sys_ptrace+0x51/0x60 kernel/ptrace.c:1242
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 14119 Comm: syz-executor.4 Not tainted 5.10.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/11/04 02:02 upstream 4ef8451b3326 cba33199 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.