From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f207.google.com (mail-oi1-f207.google.com [209.85.167.207]) (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 5C3A2369D75 for ; Mon, 3 Aug 2026 10:48:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785754108; cv=none; b=iQzHsJHgG50J9QRf6wr4lBsVeJZKEWNcvBN4CmbLuEUNugAv68JslRH4+Ec7C2fVpE3q5/+B/VIwiSDITKBjT+WGG0pFH7H+MbxQMqnEUA3l6L4oj6c9gaQC/TWwYlkVIjcaeOVdG+eThoTQVcZAdJY9tSJjDQ0oWXbj4Ein5mg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785754108; c=relaxed/simple; bh=IQECFOSabs7iDNwI1oqMe3HiNyiXN4p0L+0bXP7yHEU=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=GmRxHoj29Rg6LfefQcAYpnTV9KaBBNYnu6VHmdcYnLKqzLmR1rxv+YTDYdL6zi/vs41pwEJkUKYZ4hrSyuGsxnM/1T9jH3r8lemOcyTI5C/5J3lS3uCLl/mn0/RjjGwZAc4k3jjTGzsuzRx+5n+5IcCeTqAwVIOoDhfcINjbtpI= 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=209.85.167.207 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-oi1-f207.google.com with SMTP id 5614622812f47-4a41f46d629so4755692b6e.3 for ; Mon, 03 Aug 2026 03:48:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785754105; x=1786358905; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=5XcHfcrqk1LciEtgM1fh03VkDbfVuXIi5D6H/T0h+d8=; b=efEuNl/d1mxOKSs+86nIbrBDmIkMAZ+FtdFV4mpdVqoYYgpYAwpCgNrDDxf/dl2D7t jNKjIFA78sbyQ8VDWv2K0XBJ4lre41ss55cxOFZpxrN1WOSxRz8HV2zjBOF5OBUQ/bpP r9d90EDRqE6me1r7dhPU0gO4NMdBdMbJxxshnDwx+KFy4B3WSBvMznF3TMku+BfyQ6VQ qRZ1qSkfUXo8h4RkiqZqoLl9ZDvMFcunu1doxb2CbtfhkBLG3Z5W/w+/BaLlBW6n4Na4 UmRW2wg1InhF4sAbCK/Ll97QSR7jhXsSQ+Dr5q6wIlIlWiswf6Ab9YBpDJTFjgj+TYWT pcAg== X-Forwarded-Encrypted: i=1; AHgh+RqGRxBqRUNPYzS9Q58QHj4r/0KB9dgN8qDacU9J1Hk9c1KdE661NMHZJuZT4qXEXVmXZQRXNoYND1A73CU=@vger.kernel.org X-Gm-Message-State: AOJu0YxknWivMp8yBUUseofAX15XC8o8dGXdvvO1ohzMA4Et5+DH5qMT F1VPr1LCrYkJ60I/irl/WwU2wj6IoIX0r+4TG5TDokyHIHvxde1JLv3zk9wGqbStxzdGjCM58oF Xn1gbpU9M6wwpAK6AkIS9jgU1OD0UpdwYwDlbwfOJGwBaKzxMZlsy8/w7NLI= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:14c6:b0:4a3:4598:f390 with SMTP id 5614622812f47-4af5e3d7eabmr14546521b6e.17.1785754105395; Mon, 03 Aug 2026 03:48:25 -0700 (PDT) Date: Mon, 03 Aug 2026 03:48:25 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a7071f9.f794c993.27aeb.002f.GAE@google.com> Subject: [syzbot] [usb?] possible deadlock in tcm_alloc From: syzbot To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 11028ab62899 Merge tag 'probes-fixes-v7.2-rc5' of git://gi.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=10994aea580000 kernel config: https://syzkaller.appspot.com/x/.config?x=145fa60d73086782 dashboard link: https://syzkaller.appspot.com/bug?extid=2799146a53c356f8017d compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-11028ab6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/e2be78614a29/vmlinux-11028ab6.xz kernel image: https://storage.googleapis.com/syzbot-assets/301a11d315af/bzImage-11028ab6.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+2799146a53c356f8017d@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.239/6703 is trying to acquire lock: ffffffff90252b60 (tpg_instances_lock){+.+.}-{4:4}, at: tcm_alloc+0x20/0x440 drivers/usb/gadget/function/f_tcm.c:2733 but task is already holding lock: ffff888058a66390 (&gi->lock){+.+.}-{4:4}, at: config_usb_cfg_link+0x57/0x3a0 drivers/usb/gadget/configfs.c:439 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&gi->lock){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821 config_usb_cfg_link+0x57/0x3a0 drivers/usb/gadget/configfs.c:439 configfs_symlink+0x540/0x11f0 fs/configfs/symlink.c:196 vfs_symlink fs/namei.c:5660 [inline] vfs_symlink+0x178/0x4d0 fs/namei.c:5639 filename_symlinkat+0x2a6/0x560 fs/namei.c:5685 __do_sys_symlinkat fs/namei.c:5705 [inline] __se_sys_symlinkat fs/namei.c:5700 [inline] __x64_sys_symlinkat+0x9c/0xe0 fs/namei.c:5700 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&sb->s_type->i_mutex_key#24){++++}-{4:4}: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 down_write+0x8b/0x1f0 kernel/locking/rwsem.c:1631 inode_lock include/linux/fs.h:1024 [inline] configfs_depend_item_unlocked+0xf3/0x6a0 fs/configfs/dir.c:1259 usbg_make_tpg+0x261/0x620 drivers/usb/gadget/function/f_tcm.c:1686 target_fabric_make_tpg+0xab/0x8c0 drivers/target/target_core_fabric_configfs.c:939 configfs_mkdir+0x51e/0xb70 fs/configfs/dir.c:1360 vfs_mkdir+0x361/0x850 fs/namei.c:5276 filename_mkdirat+0x48b/0x5e0 fs/namei.c:5309 __do_sys_mkdir fs/namei.c:5336 [inline] __se_sys_mkdir fs/namei.c:5333 [inline] __x64_sys_mkdir+0x6b/0x90 fs/namei.c:5333 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&opts->dep_lock){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821 usbg_make_tpg+0x1a4/0x620 drivers/usb/gadget/function/f_tcm.c:1678 target_fabric_make_tpg+0xab/0x8c0 drivers/target/target_core_fabric_configfs.c:939 configfs_mkdir+0x51e/0xb70 fs/configfs/dir.c:1360 vfs_mkdir+0x361/0x850 fs/namei.c:5276 filename_mkdirat+0x48b/0x5e0 fs/namei.c:5309 __do_sys_mkdir fs/namei.c:5336 [inline] __se_sys_mkdir fs/namei.c:5333 [inline] __x64_sys_mkdir+0x6b/0x90 fs/namei.c:5333 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (tpg_instances_lock){+.+.}-{4:4}: check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3165 check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x136c/0x1a40 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821 tcm_alloc+0x20/0x440 drivers/usb/gadget/function/f_tcm.c:2733 usb_get_function+0x5e/0xd0 drivers/usb/gadget/functions.c:61 config_usb_cfg_link+0x1ed/0x3a0 drivers/usb/gadget/configfs.c:469 configfs_symlink+0x540/0x11f0 fs/configfs/symlink.c:196 vfs_symlink fs/namei.c:5660 [inline] vfs_symlink+0x178/0x4d0 fs/namei.c:5639 filename_symlinkat+0x2a6/0x560 fs/namei.c:5685 __do_sys_symlinkat fs/namei.c:5705 [inline] __se_sys_symlinkat fs/namei.c:5700 [inline] __x64_sys_symlinkat+0x9c/0xe0 fs/namei.c:5700 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: tpg_instances_lock --> &sb->s_type->i_mutex_key#24 --> &gi->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&gi->lock); lock(&sb->s_type->i_mutex_key#24); lock(&gi->lock); lock(tpg_instances_lock); *** DEADLOCK *** 3 locks held by syz.0.239/6703: #0: ffff888024522450 (sb_writers#13){.+.+}-{0:0}, at: filename_create+0x10d/0x400 fs/namei.c:4948 #1: ffff888057d20ac0 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #1: ffff888057d20ac0 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: configfs_symlink+0x3c0/0x11f0 fs/configfs/symlink.c:186 #2: ffff888058a66390 (&gi->lock){+.+.}-{4:4}, at: config_usb_cfg_link+0x57/0x3a0 drivers/usb/gadget/configfs.c:439 stack backtrace: CPU: 2 UID: 0 PID: 6703 Comm: syz.0.239 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3165 check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x136c/0x1a40 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821 tcm_alloc+0x20/0x440 drivers/usb/gadget/function/f_tcm.c:2733 usb_get_function+0x5e/0xd0 drivers/usb/gadget/functions.c:61 config_usb_cfg_link+0x1ed/0x3a0 drivers/usb/gadget/configfs.c:469 configfs_symlink+0x540/0x11f0 fs/configfs/symlink.c:196 vfs_symlink fs/namei.c:5660 [inline] vfs_symlink+0x178/0x4d0 fs/namei.c:5639 filename_symlinkat+0x2a6/0x560 fs/namei.c:5685 __do_sys_symlinkat fs/namei.c:5705 [inline] __se_sys_symlinkat fs/namei.c:5700 [inline] __x64_sys_symlinkat+0x9c/0xe0 fs/namei.c:5700 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f358b59df99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f358c541028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007f358b825fa0 RCX: 00007f358b59df99 RDX: 0000200000000400 RSI: ffffffffffffff9c RDI: 0000200000000300 RBP: 00007f358b634ec4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f358b826038 R14: 00007f358b825fa0 R15: 00007ffdf9fc7e88 --- This report is generated by a bot. 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