From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f205.google.com (mail-il1-f205.google.com [209.85.166.205]) (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 DB7B228935C for ; Tue, 8 Jul 2025 12:40:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.205 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751978428; cv=none; b=IJxsoslp7JA9Ex2jstL2kI5cnGqQzAJmOM+W3qZQ+ESPPJ6IPCGJQQtY2z2Tg2cn+8vzWi9vTIBCoFFHg9fTRp6MmQF0qmIiemYw9VS314FYeN9ZEgxTBRUIWCSjyu9+H4aMBo579ErngTF8ZrHKABWJ2VynO/qCtLbGx2f0/kQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751978428; c=relaxed/simple; bh=O/mt5Laig4YvyGxBOM7n5YBR4Qhf37DNVb8KTwe0N+4=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=R9hz+EgnWchjh463gedxTxWg0w0vA3Gs6/uyqiUEzf01R1bKCBf/NuvElaOrrBbGkqSux6ZMqTuwD3bDZE1ua+wCLxG4wEYeWZamyKzVnwDvhJ3qTsaUeR2XlmK8kl6XFcEV7X/O5XfiAp9eTviLDBlCFgh7pOxJXgNUtzC0Isw= 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=209.85.166.205 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-f205.google.com with SMTP id e9e14a558f8ab-3df4022687eso40922595ab.1 for ; Tue, 08 Jul 2025 05:40:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1751978426; x=1752583226; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=zNeagxp53Cib7FyDAeK/ti1QQrnWh7OkocmUSUE0k20=; b=kdpAxv0dO/w9Z29tt382SQDHM3xZU/Rmj5slCTynVio2/eYdVCQVrSdAgfkAo9VneB OYPTJby3kvx5Ei6KBYVPaSxpLAiobZfbkpKvwz9LSfvMdBTYjhvsjU7ykDOg0ao3B3Oy ezB+6JocNuZE3WND72V2Td8L1aC1Gm1LkrOmZ+qa4+WkTzrD9wFoYqPtsd4oFL4zw3EU 4GtkqqWR6xiwDyexEod4m+wFyS5xjsWS524By0E5c6+ZJ/bwj1RdWKEGsaIkVBwX9W9Z GPOFonJ693b0dE8k6K4zJbk6C/ZzKWAdvmRkjy3+g2weDqZGW89Icpq9+9RqeIOFM6uH zTQg== X-Forwarded-Encrypted: i=1; AJvYcCVEXKdN4mFC5J3WtKvR0t7HaDPOyqmcJ4678aTR/CjPPdmJbXLmf3zGPAHPuS4YojC4g13SXqgxUZIvLXU=@vger.kernel.org X-Gm-Message-State: AOJu0YxOILWgoPz9bpwcL6NbFBs8ffeE9sUtgcVSEbgmc5Y7AJs1XMRC DZ3DDRXYjbFINkQI6MGT0MvsmEnF0Xwz/qcrhli+eGNTmkF0RbcLn8Yu81Rpx0wlIWtyrSENrtR mdykfan5Xs79kmZdl0EZzV9/Abp0GzlXnCxjZNFywqswLkqnDl3l0CKi+uO4= X-Google-Smtp-Source: AGHT+IHW29YJ0mMkJYKj8RbFg2PDoBHxN7Fim5IsU3FV9f0fYeHOL+oENDpilrPghcgkrhRME5kY/BWHO2MReuuphrGQjynxh0a5 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:112:b0:3dd:bf91:23f7 with SMTP id e9e14a558f8ab-3e154e51b43mr20192605ab.7.1751978425899; Tue, 08 Jul 2025 05:40:25 -0700 (PDT) Date: Tue, 08 Jul 2025 05:40:25 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <686d11b9.050a0220.1ffab7.0009.GAE@google.com> Subject: [syzbot] [net?] possible deadlock in ptp_clock_adjtime From: syzbot To: andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, richardcochran@gmail.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: d7b8f8e20813 Linux 6.16-rc5 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12b3728c580000 kernel config: https://syzkaller.appspot.com/x/.config?x=c963f5de3d9eab7d dashboard link: https://syzkaller.appspot.com/bug?extid=28ddd7a3988eea351eb3 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/b35e485ae779/disk-d7b8f8e2.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/8478fc45f5f6/vmlinux-d7b8f8e2.xz kernel image: https://storage.googleapis.com/syzbot-assets/86a991e3c539/bzImage-d7b8f8e2.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+28ddd7a3988eea351eb3@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected 6.16.0-rc5-syzkaller #0 Tainted: G U ------------------------------------------------------ syz.0.4267/20512 is trying to acquire lock: ffff88802ffba868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at: ptp_vclock_in_use drivers/ptp/ptp_private.h:113 [inline] ffff88802ffba868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at: ptp_vclock_in_use drivers/ptp/ptp_private.h:99 [inline] ffff88802ffba868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at: ptp_clock_freerun drivers/ptp/ptp_private.h:130 [inline] ffff88802ffba868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at: ptp_clock_freerun drivers/ptp/ptp_private.h:125 [inline] ffff88802ffba868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at: ptp_clock_adjtime+0x527/0x760 drivers/ptp/ptp_clock.c:125 but task is already holding lock: ffff88802ffba130 (&clk->rwsem){++++}-{4:4}, at: get_posix_clock kernel/time/posix-clock.c:25 [inline] ffff88802ffba130 (&clk->rwsem){++++}-{4:4}, at: get_clock_desc+0x125/0x240 kernel/time/posix-clock.c:209 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&clk->rwsem){++++}-{4:4}: down_write+0x92/0x200 kernel/locking/rwsem.c:1577 posix_clock_unregister+0x4d/0xd0 kernel/time/posix-clock.c:184 ptp_clock_unregister+0x14f/0x250 drivers/ptp/ptp_clock.c:432 ptp_vclock_unregister+0x11a/0x160 drivers/ptp/ptp_vclock.c:228 unregister_vclock+0x108/0x1a0 drivers/ptp/ptp_sysfs.c:177 device_for_each_child_reverse+0x133/0x1a0 drivers/base/core.c:4051 n_vclocks_store+0x4b6/0x6d0 drivers/ptp/ptp_sysfs.c:241 dev_attr_store+0x58/0x80 drivers/base/core.c:2440 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x354/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6c4/0x1150 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&ptp->n_vclocks_mux){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain kernel/locking/lockdep.c:3911 [inline] __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240 lock_acquire kernel/locking/lockdep.c:5871 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:747 ptp_vclock_in_use drivers/ptp/ptp_private.h:113 [inline] ptp_vclock_in_use drivers/ptp/ptp_private.h:99 [inline] ptp_clock_freerun drivers/ptp/ptp_private.h:130 [inline] ptp_clock_freerun drivers/ptp/ptp_private.h:125 [inline] ptp_clock_adjtime+0x527/0x760 drivers/ptp/ptp_clock.c:125 pc_clock_adjtime+0x115/0x1e0 kernel/time/posix-clock.c:239 do_clock_adjtime kernel/time/posix-timers.c:1162 [inline] __do_sys_clock_adjtime+0x172/0x290 kernel/time/posix-timers.c:1174 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&clk->rwsem); lock(&ptp->n_vclocks_mux); lock(&clk->rwsem); lock(&ptp->n_vclocks_mux); *** DEADLOCK *** 1 lock held by syz.0.4267/20512: #0: ffff88802ffba130 (&clk->rwsem){++++}-{4:4}, at: get_posix_clock kernel/time/posix-clock.c:25 [inline] #0: ffff88802ffba130 (&clk->rwsem){++++}-{4:4}, at: get_clock_desc+0x125/0x240 kernel/time/posix-clock.c:209 stack backtrace: CPU: 0 UID: 0 PID: 20512 Comm: syz.0.4267 Tainted: G U 6.16.0-rc5-syzkaller #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2046 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain kernel/locking/lockdep.c:3911 [inline] __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240 lock_acquire kernel/locking/lockdep.c:5871 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:747 ptp_vclock_in_use drivers/ptp/ptp_private.h:113 [inline] ptp_vclock_in_use drivers/ptp/ptp_private.h:99 [inline] ptp_clock_freerun drivers/ptp/ptp_private.h:130 [inline] ptp_clock_freerun drivers/ptp/ptp_private.h:125 [inline] ptp_clock_adjtime+0x527/0x760 drivers/ptp/ptp_clock.c:125 pc_clock_adjtime+0x115/0x1e0 kernel/time/posix-clock.c:239 do_clock_adjtime kernel/time/posix-timers.c:1162 [inline] __do_sys_clock_adjtime+0x172/0x290 kernel/time/posix-timers.c:1174 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffbd478e929 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:00007ffbd5676038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007ffbd49b6080 RCX: 00007ffbd478e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: fffffffffffffffb RBP: 00007ffbd4810b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffbd49b6080 R15: 00007fff4cf8c228 --- This report is generated by a bot. 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