syzbot


KCSAN: data-race in exit_mmap / io_unaccount_mem

Status: auto-closed as invalid on 2021/03/18 14:19
Subsystems: fs
[Documentation on labels]
First crash: 1189d, last: 1167d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in exit_mmap / io_unaccount_mem

write to 0xffff888101a1e210 of 8 bytes by task 13572 on cpu 1:
 io_unaccount_mem+0xdb/0x150 fs/io_uring.c:8276
 io_ring_ctx_wait_and_kill+0x2e9/0x3a0 fs/io_uring.c:8805
 io_uring_release+0x3e/0x50 fs/io_uring.c:8823
 __fput+0x24e/0x4e0 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0x8e/0x110 kernel/task_work.c:140
 exit_task_work include/linux/task_work.h:30 [inline]
 do_exit+0x494/0x1690 kernel/exit.c:825
 do_group_exit+0xce/0x180 kernel/exit.c:922
 get_signal+0xdce/0x14e0 kernel/signal.c:2773
 arch_do_signal_or_restart+0x2a/0x270 arch/x86/kernel/signal.c:811
 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+0x11a/0x1b0 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:294
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888101a1e210 of 8 bytes by task 13551 on cpu 0:
 exit_mmap+0x94/0x400 mm/mmap.c:3200
 __mmput+0xa2/0x220 kernel/fork.c:1082
 mmput+0x38/0x40 kernel/fork.c:1103
 exit_mm+0x33f/0x430 kernel/exit.c:501
 do_exit+0x41f/0x1690 kernel/exit.c:812
 do_group_exit+0xce/0x180 kernel/exit.c:922
 get_signal+0xdce/0x14e0 kernel/signal.c:2773
 arch_do_signal_or_restart+0x2a/0x270 arch/x86/kernel/signal.c:811
 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+0x11a/0x1b0 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:294
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13551 Comm: syz-executor.1 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/02/11 14:13 upstream 291009f656e8 a52ee10a .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in exit_mmap / io_unaccount_mem
2021/01/31 08:08 upstream 8c947645151c fc9fd31e .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in exit_mmap / io_unaccount_mem
2021/01/20 02:45 upstream 1e2a199f6ccd 63631df1 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in exit_mmap / io_unaccount_mem
* Struck through repros no longer work on HEAD.