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KCSAN: data-race in futex_wait_queue_me / get_task_exe_file (2)

Status: auto-closed as invalid on 2021/05/26 09:36
Subsystems: kernel
[Documentation on labels]
First crash: 1093d, last: 1093d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in futex_wait_queue_me / get_task_exe_file kernel 1 1131d 1131d 0/26 auto-closed as invalid on 2021/04/18 02:56

Sample crash report:
==================================================================
BUG: KCSAN: data-race in futex_wait_queue_me / get_task_exe_file

write to 0xffff88810799d02c of 4 bytes by task 20119 on cpu 1:
 freezer_do_not_count include/linux/freezer.h:109 [inline]
 freezable_schedule include/linux/freezer.h:171 [inline]
 futex_wait_queue_me+0x198/0x260 kernel/futex.c:2606
 futex_wait+0x143/0x430 kernel/futex.c:2708
 do_futex+0x9e8/0x1e10 kernel/futex.c:3734
 __do_sys_futex kernel/futex.c:3797 [inline]
 __se_sys_futex+0x2a8/0x390 kernel/futex.c:3763
 __x64_sys_futex+0x74/0x80 kernel/futex.c:3763
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88810799d02c of 4 bytes by task 20122 on cpu 0:
 get_task_exe_file+0x44/0x140 kernel/fork.c:1196
 proc_exe_link+0x44/0x100 fs/proc/base.c:1725
 proc_pid_get_link+0x50/0xb0 fs/proc/base.c:1750
 pick_link fs/namei.c:1737 [inline]
 step_into+0x974/0xec0 fs/namei.c:1799
 open_last_lookups fs/namei.c:3314 [inline]
 path_openat+0xfc8/0x20b0 fs/namei.c:3497
 do_filp_open+0xd9/0x1f0 fs/namei.c:3527
 do_sys_openat2+0xa3/0x250 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_openat fs/open.c:1219 [inline]
 __se_sys_openat fs/open.c:1214 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1214
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 20122 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
2021/04/21 09:35 upstream 1fe5501ba1ab 95777977 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in futex_wait_queue_me / get_task_exe_file
* Struck through repros no longer work on HEAD.