From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pz2-f12.google.com (mail-pz2-f12.google.com [74.125.228.12]) (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 3309C4CCDE3 for ; Thu, 10 Sep 2026 16:23:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.228.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789057419; cv=none; b=tf+26Fpl4CRRJE+i2BuOAqkEO9CJClvRrBvI8NN2ElpBLNwclpnoIc06gay3Ja2w3T5aIlSllnHb5RfMgoYDHgP73JLdboyLFI8UBWEBUqK2kWwFIxt8PiB3EhCDIEaPkpq1CMM1AIMzAOq5W5q9JPAPkJH1gtdKR5weeA2LNos= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789057419; c=relaxed/simple; bh=kjpF59fe4ubdCkFvENJAVeCWzv0Fgh94P0CK6dGCBfM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eqi9Xv+h8ePX0VfTWkG7LADiKNjsMF9wKTTSfnELWL+9cb5dKQQ1CEQpO6yAcIsfL4E7kViPfmNbmadgaqoLJEYGZS35LOefJDmUE7/SBnAOy8ybCJYtVkeqHm74OSO2ecf1JhPDkkoVBx+eZqF9Tgw82jNBsihqzNXgST0I71Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Q7v+Z2n1; arc=none smtp.client-ip=74.125.228.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Q7v+Z2n1" Received: by mail-pz2-f12.google.com with SMTP id d2e1a72fcca58-85469e2540eso1113794b3a.1 for ; Thu, 10 Sep 2026 09:23:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1789057418; x=1789662218; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=ERs0ZBdo2a6X8YAmXloXdwhR0inMOSFiQbLLSRZtan0=; b=Q7v+Z2n17/VJ/L+PXGe7WlkcqwxZOQsbW431z/jVXAwY/ngB4i1vRxb8qg1jmd/dX3 O9wNoHnoprUCUvLxMuv3pWQ+aq+2QhjYHQWCeovs5Db7px2eAFY2i0jTlADR1LmF21aM ERCHxtffTpphvgMRw82QkrGSps7QuGV/v96Iprq9hMVbilj6CYVr7XXPD4IURvW+Tc1c sGc3R3paHUVjmT+ka6YKddie6xBBP7DizAb4ZMSVHPyLson7Wzh4ecjguMNJgWgAK0Uk 6tDccap6g7QLvpmymsr6kJy0ctbNObL1Rwsz1ICDhI5QocbZ3HngckeY51gJPOBfWdET txkA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1789057418; x=1789662218; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=ERs0ZBdo2a6X8YAmXloXdwhR0inMOSFiQbLLSRZtan0=; b=JUOMm/1969m1Uzfd0Y/pv5t+ku1ERpJ4cmLPtXLawtjUnTj5K7MV7M5K7bDofKsEU+ wfl5fIn3yhbQrEd2ST6x8xPvpggtpKJ7NmD63L202N8hIPytl1BMM/k2ior+ow1+jP0T +trUHNeeAA7plIGsiB2HDGJlYX23JgQPwqKJ5EH1Edr7/32SS+UmZue3k6auVfSkMAll zuvSLxpBc7JIX1S9FhmhmuQxMlR34geNaAATZ3/DEp09nckOmhjs6DI5AsFPS7SCKlMu etOdxamA1Q89HvYUMjUq91XqFSZ9bnqmVNoI+PBboY9mQRq6ga6wi9VmhsF56mwZ34Pj 9byw== X-Gm-Message-State: AFuF++k5dRHd9py1A1Mp6iy+7+o4c2+fpRwGF3PupDuaueG6M/I72Di4 4jlmdXQSwPS9CHVv5djbpvdLUwah9lXTowmsaabhRjdiQK849/k25Jf/ X-Gm-Gg: AYBFou3qarhVDnjcSjhPk3wspRrF0iINiSMZK5uEtw2GPK3xI79KDSEMGVFQj+J1CRH WgCW+eyr6cFqBBYn5fh4amv4RNEkg/JwSgwA8Te0muLcKuqemz4QY09PEhKlPX5GOeoCCpkQJMD e2jmP6K5321SiDEmJLqw5PgmXyg12eSMwTd8wEanT+6BWwrDGYuPPbN04PNRCwDvQ5+Y9haACki 1htMK6mFxAYfFQFmWFwDaJm9ET7UlzS5kCKjulzbej10AW41p9fM6pGissHDNFhNtN9bbTFTA4U +5FIohDK6C1skvg2bmMvxROMgYF4J0/6xBZG5iQK8+I4vdwKaX+x74Qe0HHFe5rkN0EY/K0qXBt gfKejZ+PzOEk9fFinyoSTA35hrYPo0gkX0kHjbNNddR19Ty+3KfJm4Rinf0TEcRkJGPPHs8LlSb 5fJxLOxJUrbggDtZvcGIseoa1PCqpDgeBZUFRhINZQbAiLreXPWVGiCD1HUwJFCeoqcW+XIE7ws AazeH3XBsTAqAcLt1c= X-Received: by 2002:a05:6a00:80f:b0:857:7384:b5f7 with SMTP id d2e1a72fcca58-8694801d67bmr8118952b3a.19.1789057417450; Thu, 10 Sep 2026 09:23:37 -0700 (PDT) Received: from thangnn-ASUS.. ([2405:4802:1d38:5c70:ced9:ef96:e152:2608]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-86343e6dae6sm6895066b3a.11.2026.09.10.09.23.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Sep 2026 09:23:37 -0700 (PDT) From: Nguyen Ngoc Thang To: Jiri Kosina , Benjamin Tissoires Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+093e05755c2d99caab91@syzkaller.appspotmail.com, Dmitry Torokhov , sashiko-bot@kernel.org, Nguyen Ngoc Thang Subject: [PATCH v2] HID: multitouch: use GFP_ATOMIC for report/application allocations Date: Thu, 10 Sep 2026 23:23:31 +0700 Message-ID: <20260910162331.31578-1-ngocthang2710.1999@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260910155305.58E4A1F000FF@smtp.kernel.org> References: <20260910155305.58E4A1F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-input@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit mt_allocate_report_data() and mt_allocate_application() devm_kzalloc() with GFP_KERNEL, but they are reachable from mt_event()/mt_report() via hid_report_raw_event(), which can run in (soft)irq context off a USB URB completion (e.g. dummy_hcd's hrtimer softirq). GFP_KERNEL there may call into fs_reclaim, which lockdep flags as an inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} use of fs_reclaim, alongside a "sleeping function called from invalid context" splat. Switch both to GFP_ATOMIC since neither is on a path that needs to sleep. mt_allocate_usage() is left at GFP_KERNEL: it is only reached from mt_touch_input_mapping(), which runs at probe time (hid_hw_start()), never from mt_event(), so it does not need the downgrade. Reported-by: syzbot+093e05755c2d99caab91@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=093e05755c2d99caab91 Signed-off-by: Nguyen Ngoc Thang --- v2: - Keep mt_allocate_usage() at GFP_KERNEL. It is only reached from mt_touch_input_mapping(), at probe time, never from mt_event(), so the GFP_ATOMIC downgrade there was unnecessary. (feedback from sashiko-bot) --- drivers/hid/hid-multitouch.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c index 2c41bacab1ca..9b78f8f23fcf 100644 --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -604,6 +604,7 @@ static struct mt_usages *mt_allocate_usage(struct hid_device *hdev, { struct mt_usages *usage; + /* only called from mt_touch_input_mapping(), at probe time */ usage = devm_kzalloc(&hdev->dev, sizeof(*usage), GFP_KERNEL); if (!usage) return NULL; @@ -633,8 +634,9 @@ static struct mt_application *mt_allocate_application(struct mt_device *td, unsigned int application = report->application; struct mt_application *mt_application; + /* may run from hid_report_raw_event() in (soft)irq context */ mt_application = devm_kzalloc(&td->hdev->dev, sizeof(*mt_application), - GFP_KERNEL); + GFP_ATOMIC); if (!mt_application) return NULL; @@ -692,7 +694,8 @@ static struct mt_report_data *mt_allocate_report_data(struct mt_device *td, struct hid_field *field; int r, n; - rdata = devm_kzalloc(&td->hdev->dev, sizeof(*rdata), GFP_KERNEL); + /* may run from hid_report_raw_event() in (soft)irq context */ + rdata = devm_kzalloc(&td->hdev->dev, sizeof(*rdata), GFP_ATOMIC); if (!rdata) return NULL; -- 2.43.0