From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f77.google.com (mail-oa1-f77.google.com [209.85.160.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1D8563C873D for ; Mon, 13 Apr 2026 12:51:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776084699; cv=none; b=OMbS5GFbpDGYFOqNvsNk6LWqw7EKAzq+5qgCsIOfbH6DJ2e7ZLMJYxN43FjmY7mtZY+94f/LO3eA1mn2RIO7YtgTsFXnHA25ParmDP5idIXXIR/eYnmQKmRVkhdgwUQso9vCxM7P+hFTq76+IwhGTQywGCJdWae8zjeQIqe7pq0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776084699; c=relaxed/simple; bh=23inD9JIIZjzCV4/Xchyn5qBDzAOZr/JfA0i5oTHoRM=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=Vons7jG37dqj8fv1eF1Qzamlr04Y3wPh/G2Hl190++DJA6fgfmqZnTx4iMr40bCIwmPq0rQmV5wYsVsok43AzrpbdwZvcA06y3mNHugO3wAAFofdLyfITDd4mNIHhPbzebvJ1irwHi6hF6X48fLQveLANlr3rWPOt/Tg0hR74jU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.160.77 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oa1-f77.google.com with SMTP id 586e51a60fabf-41c08879ba3so6789427fac.0 for ; Mon, 13 Apr 2026 05:51:37 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776084697; x=1776689497; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=jRIdr1VgrQYf+zTp1aY4GLpmv27r2Op9rfFRPV8Wt6k=; b=gZY55gGxVxd7gQJoGWypQzEk3j4ybpmLVdgB8wvm7tccT1VoNld1UWMwvH0KEE6/JT e4lONj705LaNucRNuLUU1Xv4qV0r2w9vIKXWJNJkJOWX323y/WSaxRKK4bt587dqQ35V Bjs7GZsTZ+VSQIXe4iMHQcsdnIq7vQeigKtbepe4qxYpYreVCqIuxviZT/FVTrZJQNOt jLPH99Q1scyy7nLNp7h3T7jl886+zDgZhcTfKbWJL7nGa9J0c8jxt1CVD5DzYtUqQpGU cASWJ3K/WBSjnUy/EHJt5QpyoixQOjYA5ESzAEGUWt9zysyYmvHLa+tzvTlzbYNqSHNp 77XQ== X-Forwarded-Encrypted: i=1; AFNElJ8dTmd79XJZgAX36TNywPJ32yIo7bZK5Of3BpApMAMibM9DJXDcZCM5sADL71SuCybY9C1VLILN3LiNmM8=@vger.kernel.org X-Gm-Message-State: AOJu0YxcWNqH4jBKhDd2L7/kDUEvy+Jt5sOhSCF52Hn2x/JWMfrW+2Fr 9aCDr6H2B46KyI3dXKDE6rN8ywzHMpPcEx5+sUwOCOIQWVlCWVkLpuSbVayRIM/M2DcNvTpZek3 PP63Jq3z+tcBDb64eN7QIkEZzIxyqqAyQqCvKCa/AgjSv+8/BWLrln5s65gg= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4412:b0:686:f60b:dde8 with SMTP id 006d021491bc7-68a6a5ba019mr6463135eaf.24.1776084697105; Mon, 13 Apr 2026 05:51:37 -0700 (PDT) Date: Mon, 13 Apr 2026 05:51:37 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69dce6d9.a00a0220.468cb.0046.GAE@google.com> Subject: [syzbot] [perf?] KCSAN: data-race in event_sched_out / perf_mmap_rb From: syzbot To: acme@kernel.org, adrian.hunter@intel.com, alexander.shishkin@linux.intel.com, irogers@google.com, james.clark@linaro.org, jolsa@kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, mark.rutland@arm.com, mingo@redhat.com, namhyung@kernel.org, peterz@infradead.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 7c6c4ed80b87 Merge tag 'vfs-7.0-rc8.fixes' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1129b302580000 kernel config: https://syzkaller.appspot.com/x/.config?x=3a78dd265deac3a9 dashboard link: https://syzkaller.appspot.com/bug?extid=1f011f617ab8493f3fdd compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/952ebc34a0d7/disk-7c6c4ed8.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/d3c6b295fa45/vmlinux-7c6c4ed8.xz kernel image: https://storage.googleapis.com/syzbot-assets/6cbdb6b4817a/bzImage-7c6c4ed8.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+1f011f617ab8493f3fdd@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in event_sched_out / perf_mmap_rb read to 0xffff88810e381fd0 of 8 bytes by task 21833 on cpu 0: __perf_update_times kernel/events/core.c:749 [inline] perf_event_update_time kernel/events/core.c:762 [inline] perf_mmap_rb+0x71d/0x950 kernel/events/core.c:7333 perf_mmap+0x1d7/0x300 kernel/events/core.c:7460 vfs_mmap include/linux/fs.h:2070 [inline] mmap_file mm/internal.h:167 [inline] __mmap_new_file_vma mm/vma.c:2468 [inline] __mmap_new_vma mm/vma.c:2532 [inline] __mmap_region mm/vma.c:2759 [inline] mmap_region+0x195e/0x20c0 mm/vma.c:2844 do_mmap+0x9b2/0xbd0 mm/mmap.c:559 vm_mmap_pgoff+0x183/0x2d0 mm/util.c:581 ksys_mmap_pgoff+0x267/0x310 mm/mmap.c:605 x64_sys_call+0x14df/0x3020 arch/x86/include/generated/asm/syscalls_64.h:10 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f write to 0xffff88810e381fd0 of 8 bytes by task 21809 on cpu 1: __perf_update_times kernel/events/core.c:-1 [inline] perf_event_update_time kernel/events/core.c:762 [inline] perf_event_set_state kernel/events/core.c:781 [inline] event_sched_out+0x4c9/0x760 kernel/events/core.c:2484 group_sched_out kernel/events/core.c:2508 [inline] __pmu_ctx_sched_out+0x3e7/0x530 kernel/events/core.c:3555 ctx_sched_out+0x279/0x2e0 kernel/events/core.c:3646 task_ctx_sched_out+0x4d/0x70 kernel/events/core.c:2955 perf_event_context_sched_out kernel/events/core.c:3853 [inline] __perf_event_task_sched_out+0x474/0x710 kernel/events/core.c:3953 perf_event_task_sched_out include/linux/perf_event.h:1662 [inline] prepare_task_switch kernel/sched/core.c:5086 [inline] context_switch kernel/sched/core.c:5243 [inline] __schedule+0xd3b/0xd40 kernel/sched/core.c:6911 preempt_schedule_common+0x11/0x30 kernel/sched/core.c:7095 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] _raw_spin_unlock_irqrestore+0x27/0x30 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:407 [inline] __wake_up_common_lock kernel/sched/wait.c:127 [inline] __wake_up+0x88/0xb0 kernel/sched/wait.c:146 audit_log_end+0x1e0/0x250 kernel/audit.c:2804 audit_seccomp+0xdb/0x100 kernel/auditsc.c:2955 seccomp_log kernel/seccomp.c:1048 [inline] __seccomp_filter+0x8ec/0x1350 kernel/seccomp.c:1344 __secure_computing+0x81/0x150 kernel/seccomp.c:1404 syscall_trace_enter include/linux/entry-common.h:112 [inline] syscall_enter_from_user_mode_work include/linux/entry-common.h:156 [inline] syscall_enter_from_user_mode include/linux/entry-common.h:187 [inline] do_syscall_64+0xd3/0x370 arch/x86/entry/syscall_64.c:90 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x0000000003d41894 -> 0x0000000003d477ec Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 21809 Comm: syz.0.5496 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 ================================================================== --- This report is generated by a bot. 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