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 238733E557A for ; Thu, 13 Aug 2026 11:09:29 +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=1786619373; cv=none; b=O6OEYqGhkPpXsynSCDLi5AhewT5hZ/LXdgdNRliBqiIk00Dju5mem+ci/tiViF5fyAqCB49LaWqkGULNfuWq50iDZ4AmmDK+QCaCd/V8tFjYbAE9cJvYwT3cK3T/A7HKIKTm10OEiIjKxgqPBZqwy/nBwslIcXwEIJm8+wqlghI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786619373; c=relaxed/simple; bh=nklSGYzTFrEXRqDIC+vzeix++hNvYLxyahLpOEON5Xw=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=RdgBo/BMxG/KgzHu3oOWEALBLInmwwAGa7+5nCk+j+FUmECzLEIzHTM5CbOApMtV+WpAXuWw+W6+dSYdQkr7z2VpagYpoEeZwsTJZAkpG7cW0+EsSQ4zvV7lET1qjuTC8KOsk7SYtPzfq+IbzbyV+M/REpBSt74Ni/He2SsT8Kc= 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-44d0960fb5bso539781fac.2 for ; Thu, 13 Aug 2026 04:09:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786619367; x=1787224167; 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=vvy2QSHbhCXFzvruiaDhQ4QiWYHFV4jhCjoYcqQ0lcs=; b=bJD/3Dadi6Zs7Ax1fvswbeYGYi7kqUvpfpmuz4FLyIgEaNNhsRiL6QC0l2bWPq5dqU 9+eXqmW6WNjJ6BripccEchhI2+1jLlhTq1pOYcCIi/2rYTJC/QtiCGGFo1BpRJqKUsBm frnzAsy9VVmS9FHB+Q9fWdGvTT89B6G4Ua9e2q7+Ev09g5A6h5UgaG8eV43Jz3Bk0qH9 qXvI3hqlYMnqAcekk0Hnt8ho1U00Kdn4b6eL41memwEouszTE+J/jdSn91MKV6Rbvbkl wQWr2epn6OCJsmObzGW0a3Ik3Wp1PIKs43DYDcAS2y8xC7NlSodoiR0/ebxTcLS+Peln HR0w== X-Forwarded-Encrypted: i=1; AHgh+RrcNZFvgSlfxf42PJf1+iM2PyVdFcJdIYz1Pj3AEtRzcMRgjU4IUcjIX9mDnWfJbrVxogTypPHcuJxelP4=@vger.kernel.org X-Gm-Message-State: AOJu0YzueDZI8SO4J7pbej28I5G1K28A3DhgQn6AIL+I3sGBY7EHuxv2 7hLFdqZZn8/8+klQaLwsMBJ9bwqm2PnF3QknD8KACEPMl7A14ccr4k968AHZk1C2jyeB/86K8IE xcv66oZwcMH6gE5h4A7JtJkzYQsX32mNeMJkIV07qYvOLXIWA0lBdVNc+bXk= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:3104:b0:6ae:a950:9faa with SMTP id 006d021491bc7-6b0c4226407mr4203951eaf.10.1786619367550; Thu, 13 Aug 2026 04:09:27 -0700 (PDT) Date: Thu, 13 Aug 2026 04:09:27 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a7da5e7.a2bb2777.31c27d.0018.GAE@google.com> Subject: [syzbot] [usb?] possible deadlock in uvcg_frame_dw_frame_interval_store 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: 06cf61899d64 Merge tag 'x86-urgent-2026-08-08' of git://gi.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=13484149580000 kernel config: https://syzkaller.appspot.com/x/.config?x=8a233ed2ce9a8096 dashboard link: https://syzkaller.appspot.com/bug?extid=b37b42183fe588ceeb88 compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 userspace arch: i386 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-06cf6189.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/1a9de4812597/vmlinux-06cf6189.xz kernel image: https://storage.googleapis.com/syzbot-assets/e873dfe980ea/bzImage-06cf6189.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b37b42183fe588ceeb88@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.0.2631/16146 is trying to acquire lock: ffffffff901cc668 (gadget_subsys.su_mutex){+.+.}-{4:4}, at: uvcg_frame_dw_frame_interval_store+0xdf/0x4b0 drivers/usb/gadget/function/uvc_configfs.c:2076 but task is already holding lock: ffff8880275d5170 (&p->frag_sem){++++}-{4:4}, at: flush_write_buffer fs/configfs/file.c:205 [inline] ffff8880275d5170 (&p->frag_sem){++++}-{4:4}, at: configfs_write_iter+0x218/0x4e0 fs/configfs/file.c:229 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&p->frag_sem){++++}-{4:4}: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 down_write_killable+0x93/0x250 kernel/locking/rwsem.c:1643 configfs_rmdir+0x3fa/0x950 fs/configfs/dir.c:1534 vfs_rmdir fs/namei.c:5381 [inline] vfs_rmdir+0x328/0x8a0 fs/namei.c:5354 filename_rmdir+0x31a/0x5c0 fs/namei.c:5438 __do_sys_unlinkat fs/namei.c:5613 [inline] __se_sys_unlinkat fs/namei.c:5606 [inline] __ia32_sys_unlinkat+0xf5/0x130 fs/namei.c:5606 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #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] __ia32_sys_mkdir+0x6a/0x90 fs/namei.c:5333 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #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 tcm_set_name+0x29/0xb0 drivers/usb/gadget/function/f_tcm.c:2669 function_make+0x21c/0x3f0 drivers/usb/gadget/configfs.c:636 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] __ia32_sys_mkdir+0x6a/0x90 fs/namei.c:5333 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #0 (gadget_subsys.su_mutex){+.+.}-{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 uvcg_frame_dw_frame_interval_store+0xdf/0x4b0 drivers/usb/gadget/function/uvc_configfs.c:2076 flush_write_buffer fs/configfs/file.c:207 [inline] configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e other info that might help us debug this: Chain exists of: gadget_subsys.su_mutex --> &sb->s_type->i_mutex_key#24 --> &p->frag_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&p->frag_sem); lock(&sb->s_type->i_mutex_key#24); lock(&p->frag_sem); lock(gadget_subsys.su_mutex); *** DEADLOCK *** 4 locks held by syz.0.2631/16146: #0: ffff8880211ceb70 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259 #1: ffff888022078450 (sb_writers#12){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #2: ffff888075cc2e80 (&buffer->mutex#2){+.+.}-{4:4}, at: configfs_write_iter+0x76/0x4e0 fs/configfs/file.c:226 #3: ffff8880275d5170 (&p->frag_sem){++++}-{4:4}, at: flush_write_buffer fs/configfs/file.c:205 [inline] #3: ffff8880275d5170 (&p->frag_sem){++++}-{4:4}, at: configfs_write_iter+0x218/0x4e0 fs/configfs/file.c:229 stack backtrace: CPU: 1 UID: 0 PID: 16146 Comm: syz.0.2631 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP 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 uvcg_frame_dw_frame_interval_store+0xdf/0x4b0 drivers/usb/gadget/function/uvc_configfs.c:2076 flush_write_buffer fs/configfs/file.c:207 [inline] configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f93fec Code: Unable to access opcode bytes at 0xf7f93fc2. RSP: 002b:00000000f545650c EFLAGS: 00000292 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080000080 RDX: 000000000000000b RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 --- 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. 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