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upstream test error: KCSAN: data-race in exit_mm / mm_update_next_owner

Status: auto-obsoleted due to no activity on 2024/03/10 07:34
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+3eec1978afe3e480bf7e@syzkaller.appspotmail.com
First crash: 69d, last: 69d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in exit_mm / mm_update_next_owner

write to 0xffff88810120c5e0 of 8 bytes by task 3110 on cpu 0:
 exit_mm+0x9b/0x180 kernel/exit.c:562
 do_exit+0x585/0x16d0 kernel/exit.c:858
 do_group_exit+0x101/0x150 kernel/exit.c:1020
 get_signal+0xf4e/0x10a0 kernel/signal.c:2893
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:105 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline]
 syscall_exit_to_user_mode+0x58/0x130 kernel/entry/common.c:212
 do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88810120c5e0 of 8 bytes by task 3109 on cpu 1:
 mm_update_next_owner+0x1a5/0x410 kernel/exit.c:494
 exit_mm+0xdb/0x180 kernel/exit.c:568
 do_exit+0x585/0x16d0 kernel/exit.c:858
 do_group_exit+0x141/0x150 kernel/exit.c:1020
 __do_sys_exit_group kernel/exit.c:1031 [inline]
 __se_sys_exit_group kernel/exit.c:1029 [inline]
 __x64_sys_exit_group+0x1f/0x20 kernel/exit.c:1029
 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: 0xffff888104362a00 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3109 Comm: syz-executor.0 Not tainted 6.8.0-rc2-syzkaller-00476-g3a0e92207940 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/04 07:33 upstream 3a0e92207940 a67b2c42 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce upstream test error: KCSAN: data-race in exit_mm / mm_update_next_owner
* Struck through repros no longer work on HEAD.