From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f198.google.com (mail-oi1-f198.google.com [209.85.167.198]) (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 46E7B30DD22 for ; Tue, 11 Aug 2026 05:12:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786425125; cv=none; b=GxDwreROPlqEi/7hsqayzVB6kzN7A5I4ziHPpkQjjCRaogASuVRgKx6xI+cTy5KbJLHSmdx7AEyyQXaeXk5c27f/iKPy+QN4dUNhwHBGldG6Y9Ijiduk6BcQKA9RSVNoBLPEUJaQrFxkG9p2kzErPCi69bBBvpdjyTyZeYZkg3E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786425125; c=relaxed/simple; bh=E1fgSG70XEc308TGwbEjifBn/kxcqNQbPWrumm5L/qU=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=QPSDTXLfL3ISDFRJw6YQgVaQuBKTkZ/kz/E7yWUs3C3Tx6H3xyMcewzovFh48AjsfFGeiHKClruJPpwkqTNXL12vOo4TMSKJ7AFA1nMZklq8gJpsZqF7Q4bquc7affQgY4I+mVVNnLKY/vP1CytIZNqs80HdDmRyISgvCTgphQw= 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=209.85.167.198 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-f198.google.com with SMTP id 5614622812f47-4ab8b4887d4so1727524b6e.1 for ; Mon, 10 Aug 2026 22:12:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786425123; x=1787029923; h=content-type:to:from:subject:message-id:in-reply-to:date :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=U59JoiCvzR5UvjE8CU3AIcYo/LnOyNAwJvC1JAvZP9E=; b=bcSRMNDaDhOsWj8v4cDUav3YDq6Rb4rLv4mahy8FPGNYdvVQqlE3vReGl9H/Ti/HJI jsa+yRBYsSNCY3Nl3hQPEihRvrqaDQM6EyViuvcgWBXJGoaF9PLWBLHDExB4w5iEs6wz APmbWer+GLVIsPcD9rIW5Krb/x80hppQeryj4thGKdHAPR1MRE08bMs84Ni+4Ug7+6HL ogMTc+pmoVGOuPxSq3nGbiC7EjlJmSNK4UK2yCDTRZF7w489Nwq6Crs2FhWIl5i7SARC P1ou23OY4SapqooQkwoZz6gak6jmrLbxKCvGvNDru/JJRsA1un7Nj6PrVj6VDvEdlK91 CCsg== X-Forwarded-Encrypted: i=1; AHgh+Rrvn5x1dpoW+ZK99SQAcffaSajuq5ozuOtezrIbehe96qy4lSu1FzPvDVdSgZYCSdTOLH2d8ttany7bv2o=@vger.kernel.org X-Gm-Message-State: AOJu0Ywae4tbPsXB5oL2oFcKhqtkluOFRiY9dZeUw/VwglygSsJBRnPW bNcnDI0MH6GENAvi3c/94onDL0r97x1qxu2UPP2vyU3kFktcMXfOkQ7iR6TGToqKWQToTDcwut1 63AtS7TAdUDRqtREqoDcKEXswZvX6JL+Q5b0ez2UkMET5FB0DZKU2kQZun8E= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:1a0d:b0:4b1:bc2e:3f60 with SMTP id 5614622812f47-4b1fd8141a5mr389368b6e.16.1786425123050; Mon, 10 Aug 2026 22:12:03 -0700 (PDT) Date: Mon, 10 Aug 2026 22:12:03 -0700 In-Reply-To: <6a7aa9c4.c4d3d80a.193916.4813@mx.google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a7aaf23.01d0871a.3a0d52.00be.GAE@google.com> Subject: Re: [syzbot] [usb?] WARNING: refcount bug in trace_suspend_resume (2) From: syzbot To: khiemtranzo532001@gmail.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: WARNING: refcount bug in trace_suspend_resume udc dummy_udc.1: failed to start USB Gadget filesystem: -12 gadgetfs gadget.1: probe with driver gadgetfs failed with error -12 UDC core: USB Gadget filesystem: couldn't find an available UDC ------------[ cut here ]------------ WARNING: lib/refcount.c:28 at refcount_warn_saturate+0x134/0x170 lib/refcount.c:28, CPU#1: syz.2.17/5117 refcount_t: underflow; use-after-free. Modules linked in: Kernel panic - not syncing: kernel: panic_on_warn set ... CPU: 1 UID: 0 PID: 5117 Comm: syz.2.17 Not tainted syzkaller #0 PREEMPT Hardware name: ARM-Versatile Express Call trace: [<80201998>] (dump_backtrace) from [<80201a8c>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257) r7:82a20f78 r6:00000000 r5:823338f8 r4:00000001 [<80201a74>] (show_stack) from [<8021e5b8>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201a74>] (show_stack) from [<8021e5b8>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120) [<8021e55c>] (dump_stack_lvl) from [<8021e5e4>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r7:82a20f78 r6:00000000 r5:84166e40 r4:82c82d40 [<8021e5cc>] (dump_stack) from [<80202590>] (vpanic+0x114/0x320 kernel/panic.c:651) [<8020247c>] (vpanic) from [<802027d0>] (trace_suspend_resume+0x0/0x100 kernel/panic.c:788) r7:8092f5a8 [<8020279c>] (panic) from [<80250a80>] (check_panic_on_warn kernel/panic.c:525 [inline]) [<8020279c>] (panic) from [<80250a80>] (get_taint+0x0/0x1c kernel/panic.c:520) r3:82a0b144 r2:00000001 r1:8231965c r0:82320fb8 [<80250a08>] (check_panic_on_warn) from [<80250bfc>] (__warn+0x98/0x1a4 kernel/panic.c:1104) [<80250b64>] (__warn) from [<80250ef0>] (warn_slowpath_fmt+0x1e8/0x1f4 kernel/panic.c:1144) r8:00000009 r7:8238d554 r6:dfa09da4 r5:84166e40 r4:00000000 [<80250d0c>] (warn_slowpath_fmt) from [<8092f5a8>] (refcount_warn_saturate+0x134/0x170 lib/refcount.c:28) r10:850839c0 r9:00000000 r8:830e9c10 r7:8346cc00 r6:85e35660 r5:00000000 r4:8550ca00 [<8092f474>] (refcount_warn_saturate) from [<8111fd0c>] (__refcount_sub_and_test include/linux/refcount.h:400 [inline]) [<8092f474>] (refcount_warn_saturate) from [<8111fd0c>] (__refcount_dec_and_test include/linux/refcount.h:432 [inline]) [<8092f474>] (refcount_warn_saturate) from [<8111fd0c>] (refcount_dec_and_test include/linux/refcount.h:450 [inline]) [<8092f474>] (refcount_warn_saturate) from [<8111fd0c>] (put_dev+0x4c/0x6c drivers/usb/gadget/legacy/inode.c:165) [<8111fcc0>] (put_dev) from [<8111fdd4>] (dev_release+0x48/0x6c drivers/usb/gadget/legacy/inode.c:1224) [<8111fd8c>] (dev_release) from [<805a168c>] (__fput+0xd8/0x2f4 fs/file_table.c:512) r5:040f801b r4:83981480 [<805a15b4>] (__fput) from [<805a193c>] (____fput+0x14/0x18 fs/file_table.c:540) r9:00000000 r8:841676d4 r7:82c836ac r6:84166e40 r5:841676a0 r4:00000000 [<805a1928>] (____fput) from [<8027d7c8>] (task_work_run+0x8c/0xb4 kernel/task_work.c:233) [<8027d73c>] (task_work_run) from [<80257888>] (exit_task_work include/linux/task_work.h:40 [inline]) [<8027d73c>] (task_work_run) from [<80257888>] (do_exit+0x2ac/0xadc kernel/exit.c:1009) r9:00000000 r8:dfa09e90 r7:841676d0 r6:84ff1d4c r5:84166e40 r4:84ff1c00 [<802575dc>] (do_exit) from [<8025828c>] (do_group_exit+0x40/0x8c kernel/exit.c:1152) r7:00000004 [<8025824c>] (do_group_exit) from [<80269358>] (get_signal+0xa68/0xa90 kernel/signal.c:3046) r7:00000004 r4:84166e40 [<802688f0>] (get_signal) from [<8022a630>] (do_signal arch/arm/kernel/signal.c:579 [inline]) [<802688f0>] (get_signal) from [<8022a630>] (do_work_pending+0x124/0x4f0 arch/arm/kernel/signal.c:619) r10:00000004 r9:84166e40 r8:0000001f r7:00000004 r6:8020029c r5:dfa09fb0 r4:84166e40 [<8022a50c>] (do_work_pending) from [<80200088>] (slow_work_pending+0xc/0x24) Exception stack(0xdfa09fb0 to 0xdfa09ff8) 9fa0: 0000001f 20000400 0000001f 00000000 9fc0: 00000000 00000000 00356310 00000004 003562d8 00000000 00000001 76f4f0dc 9fe0: 76f4ee88 76f4ee78 00018fa0 001309d0 60000010 00000003 r10:00000004 r9:84166e40 r8:8020029c r7:00000004 r6:00356310 r5:00000000 r4:00000000 Rebooting in 86400 seconds.. Tested on: commit: 5d5fd841 Merge 7.2-rc5 into usb-next git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-next console output: https://syzkaller.appspot.com/x/log.txt?x=162dca9e580000 kernel config: https://syzkaller.appspot.com/x/.config?x=db7ba9edb9755fc1 dashboard link: https://syzkaller.appspot.com/bug?extid=8496ab5e117502750445 compiler: arm-linux-gnueabi-gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 userspace arch: arm patch: https://syzkaller.appspot.com/x/patch.diff?x=132112c6580000