From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f208.google.com (mail-il1-f208.google.com [209.85.166.208]) (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 BD33321CA0F for ; Thu, 1 May 2025 23:10:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.208 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746141025; cv=none; b=MUYI1CewAoOc1qo5bESerlayX2y6QTgdHyYRylQ+zyART6UUYsP35HKRLTG5a6BwpY6vQ+R5GBRHQucyiaJaZQYH6beeO94l/eLEjHOZH3bDUKuaHuBdwOpLHR2PvvHHW3fEB8pmit2qujvMc4ab13j/7IMjKmt4IeKVjMuUJvA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746141025; c=relaxed/simple; bh=rCiO67wSaKR/J66Y5RaJa3XiHHnRvsJAqdp3twkFRr0=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=L9WqZ66WWnsTwQ5pIm5zOBbnHJb7GcC6LasOe+ltdascSbfvvsnyz/Ne5mSsFZfBHB8+BYmWBomZjPlYrmhLJfw6n9bnTQbSybJIkqUlJ6ETcI0qLHIwGNz4S7QcaADDZ2Qo3qzhJSpe9mZYTVuhMI/Jy/VAiivnf0eQo4t95to= 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=209.85.166.208 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-il1-f208.google.com with SMTP id e9e14a558f8ab-3d6e10f8747so14580285ab.3 for ; Thu, 01 May 2025 16:10:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746141023; x=1746745823; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=CmMunFqJ0wsYItBEBVvHHIbIV4X1ZAlRO6ddSnExrAM=; b=k0jL0XjL7bXR1rDobrXfr+cM+Wwv9nIO6ChqqrZLcyeUh8f3/8ltsRQWDAi0X5a5gO C/O82ocjMu7Zd2t6QE6AxVQA4L/4eNwnIVkRbmtRe8sXjmSjcVt9Itr8lFupJtRpkVXA 4oVKjY2GfVUG2CD2C+Tl0kuw52rZ76u2GORqg4NpCePiquksbKwYr2sSouOQYFhgoaWy PUf6Gft60A3a/iClRQ+7j+isz3xAtrBBKpzqm9TsAvzXQQ3c4SGQNXOR9XOlKtECcM3L ttkIR7pc82DcaFTclN5BcJe6KiqENsuh373ukFMjlh+UKZS8x7gslq4geDaLMZMVpNmh F/rQ== X-Gm-Message-State: AOJu0Yz2HajokjExxcSu777bTrsV+Fnp5dQXLwNSJoZq65IbD+awCuH/ iylo1/Bg9COYMH6dUbAHcZdmQx4wVhf8+ByXfWywc9CIjwisRsgQZ00KlXseMHpS7M++Bx0NASl TH++VjUbjreggszpFWtOKTxE1LDAJK1zlcKq0c3DGkuZilEmvGHJ4TmlFfA== X-Google-Smtp-Source: AGHT+IHePGwor4oDjYFlZ6AgTMwp1kt5Ebu1QDtTzbj5/n5aPAKQAnbOGU5nfMeO/496/7sL6A6NdbF2PLqvXXmbxhyV7ATREENs Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:b46:b0:3d8:1d7c:e180 with SMTP id e9e14a558f8ab-3d97c186f80mr8708795ab.6.1746141022869; Thu, 01 May 2025 16:10:22 -0700 (PDT) Date: Thu, 01 May 2025 16:10:22 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6813ff5e.050a0220.14dd7d.001b.GAE@google.com> Subject: [syzbot] [trace?] possible deadlock in print_event_fields From: syzbot To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com, mhiramat@kernel.org, rostedt@goodmis.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 5bc1018675ec Merge tag 'pci-v6.15-fixes-3' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1246a374580000 kernel config: https://syzkaller.appspot.com/x/.config?x=d61fd67fbda678a0 dashboard link: https://syzkaller.appspot.com/bug?extid=441582c1592938fccf09 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/af5f43d5128c/disk-5bc10186.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/2a6f8aa6c1e6/vmlinux-5bc10186.xz kernel image: https://storage.googleapis.com/syzbot-assets/423f4c1d2cde/bzImage-5bc10186.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+441582c1592938fccf09@syzkaller.appspotmail.com ============================================ WARNING: possible recursive locking detected 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 Tainted: G U -------------------------------------------- syz.3.3247/22963 is trying to acquire lock: ffffffff8e44b590 (trace_event_sem){++++}-{4:4}, at: print_event_fields+0x70e/0xc90 kernel/trace/trace_output.c:1049 but task is already holding lock: ffffffff8e44b590 (trace_event_sem){++++}-{4:4}, at: tracing_read_pipe+0x3e0/0xc60 kernel/trace/trace.c:6658 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(trace_event_sem); lock(trace_event_sem); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by syz.3.3247/22963: #0: ffff888027fc37b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1213 #1: ffff8880785f8090 (&iter->mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:201 [inline] #1: ffff8880785f8090 (&iter->mutex){+.+.}-{4:4}, at: tracing_read_pipe+0x65/0xc60 kernel/trace/trace.c:6626 #2: ffffffff8e44b590 (trace_event_sem){++++}-{4:4}, at: tracing_read_pipe+0x3e0/0xc60 kernel/trace/trace.c:6658 #3: ffffffff8e443170 (all_cpu_access_lock){++++}-{4:4}, at: trace_access_lock kernel/trace/trace.c:933 [inline] #3: ffffffff8e443170 (all_cpu_access_lock){++++}-{4:4}, at: trace_access_lock kernel/trace/trace.c:929 [inline] #3: ffffffff8e443170 (all_cpu_access_lock){++++}-{4:4}, at: tracing_read_pipe+0x8c7/0xc60 kernel/trace/trace.c:6659 stack backtrace: CPU: 0 UID: 0 PID: 22963 Comm: syz.3.3247 Tainted: G U 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_deadlock_bug+0x1e9/0x240 kernel/locking/lockdep.c:3042 check_deadlock kernel/locking/lockdep.c:3094 [inline] validate_chain kernel/locking/lockdep.c:3896 [inline] __lock_acquire+0xff7/0x1ba0 kernel/locking/lockdep.c:5235 lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 down_read+0x9b/0x480 kernel/locking/rwsem.c:1524 print_event_fields+0x70e/0xc90 kernel/trace/trace_output.c:1049 print_trace_fmt kernel/trace/trace.c:4208 [inline] print_trace_line+0x129a/0x17a0 kernel/trace/trace.c:4376 tracing_read_pipe+0x4b9/0xc60 kernel/trace/trace.c:6664 vfs_read+0x1de/0xc70 fs/read_write.c:568 ksys_read+0x12a/0x240 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f87f858e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f87f9439038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f87f87b5fa0 RCX: 00007f87f858e969 RDX: 0000000000000067 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007f87f8610ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f87f87b5fa0 R15: 00007ffcda5a13e8 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup