syzbot


KCSAN: data-race in get_signal / io_uring_count_inflight

Status: auto-closed as invalid on 2021/05/30 18:52
Subsystems: kernel
[Documentation on labels]
First crash: 1068d, last: 1068d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in get_signal / io_uring_count_inflight

write to 0xffff88812be9d0ac of 4 bytes by task 4859 on cpu 0:
 get_signal+0xe96/0x15d0 kernel/signal.c:2753
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x104/0x170 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x40/0x50 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812be9d0ac of 4 bytes by task 4796 on cpu 1:
 io_match_task fs/io_uring.c:1090 [inline]
 io_uring_count_inflight+0x86/0x1d0 fs/io_uring.c:8823
 io_uring_cancel_files fs/io_uring.c:8836 [inline]
 __io_uring_files_cancel+0x1ea/0x660 fs/io_uring.c:8983
 io_uring_files_cancel include/linux/io_uring.h:22 [inline]
 do_exit+0x185/0x1560 kernel/exit.c:780
 do_group_exit+0xce/0x1a0 kernel/exit.c:922
 get_signal+0xf83/0x15d0 kernel/signal.c:2781
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x104/0x170 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x40/0x50 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4796 Comm: syz-executor.3 Not tainted 5.12.0-rc8-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
2021/04/25 18:49 upstream d2d09fbe33f8 36c88236 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in get_signal / io_uring_count_inflight
* Struck through repros no longer work on HEAD.