From nobody Tue Dec 23 22:00:36 2025 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (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 9D122762D0 for ; Tue, 30 Jan 2024 19:26:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706642813; cv=none; b=dsnriGzc1CCwFkQsS9XHrCNsOctOGPqDGygPRiBlXjBTe+XiTxSFzxLw4CgsBc4NDcYHxR/ZQwFb1QKK43TX7re0a4Nyj70U/MrAA/eMaW91zArzcWo1NLYU/9qxT/MwUIwH24mesZGND2rMeAzzwzqwpcUyAWL/5yNoICLXrP4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706642813; c=relaxed/simple; bh=B2kjYhFbSp4GX9YZwdN8eIiOyb3LTIyipZNOAiaztKA=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=D4X2RQ8nTQl/SQH9McXRtUbN5io6fodVuR+Z5l3ThSKiMxdJBQ2o+Qnh23ysqCnn53mrNmD6OlVsLKNAU1x7tX3wOW0V//H8x+24nRbFCJLFo0+FaKmyENMsKiMgvxKj8R0d6aEsWq3eg8xKDMiD94IWHBH4XvwBKbKwq8dkXBg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--rdbabiera.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=jQz7ksEt; arc=none smtp.client-ip=209.85.210.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--rdbabiera.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="jQz7ksEt" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-6ddc41f35a3so3046237b3a.3 for ; Tue, 30 Jan 2024 11:26:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1706642811; x=1707247611; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=DLNcddy21SBz7KyeQPUGhNdRXI+N/Fl5AuS+wQy0vi4=; b=jQz7ksEt62MNFesKRuKqre79VxAZ5IqSVefXUflsI0dF+mUKo14pysm0PCMhWz41gk Bf0ikAaY9aMTKH/RFMENn5QICy0EGS62Qzd0djEBZb00zwRGaPYxgtxhIdxPN5fU7SMu bi7qnyxnbAMpz7JT7HBAKRMdFGcvhjOW+HR0DZsbdXjiO+Qydl6f7QbTCasxGkXzxCOz FRYYOY05/YHFfwwNv9o98CRh1cIHK5Bi9PXB4Y5OysEq2ypzMPfv+HjMFXghgD6GN2Dd ZXWQYE4R3R/690hPPGUtbjeaz/RLdcjhKeFGCODI+yLlrWolvwIxHm14poCPBUA6DePf SIrA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706642811; x=1707247611; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=DLNcddy21SBz7KyeQPUGhNdRXI+N/Fl5AuS+wQy0vi4=; b=Rrpt2/KX0OZGg0yUQNSIm+4f2sInJqJpb53RAY9UtIzDCXRKgUQW9kOs/LN3hRH5Pe Lw0h9JHhwgSo1nl+jNXP9wfA20zxa5Ls8OltRIbQiBUJQHAcDrcRW0f5ThgjF9ZXEkut Zh5jXqqD9XzordNuClf1/RQPipa1hLKD4vqgRIDj7ohLxWCAmPyMsPRw5irI+fLFikko DIM55NLqfyHuVW536aMjvb03wOd3fdSPwX+27cdxq1dZo1+gP/0sAkntaGnk3lBv2IFH vcD2Bsv4lcMIeSVdPAKpUp2kLr5UQzAQ3V3h/X3H06oHt3Kr3qI9Dg9B3tFjHwLJp5D3 rcwg== X-Gm-Message-State: AOJu0YwVDbUjjPX+t0ELZfQVW6chiulA8j2jzRz7ACd/ySt9tHTfZxoT w45rDenKBy+fsWVmVsOrxAmbHsdnmmZFa+Na8lKCkOzHXmx8YNY8WG+vwlPF/uaWQbZ8ruMwjMT aaiK1NpR6Q/q+NQ== X-Google-Smtp-Source: AGHT+IGzyqpHDnMzaRV+nS2+r1StE8p1R6XAs2/YV+zXv2KaMvdh3kwztGtHSqhYXdO4zpbBnD2dX6We83IfeZ0= X-Received: from rdbabiera.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:18a8]) (user=rdbabiera job=sendgmr) by 2002:a05:6a00:4503:b0:6db:c6a5:da3e with SMTP id cw3-20020a056a00450300b006dbc6a5da3emr1109506pfb.5.1706642810832; Tue, 30 Jan 2024 11:26:50 -0800 (PST) Date: Tue, 30 Jan 2024 19:26:39 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Developer-Key: i=rdbabiera@google.com; a=openpgp; fpr=639A331F1A21D691815CE090416E17CA2BBBD5C8 X-Developer-Signature: v=1; a=openpgp-sha256; l=2174; i=rdbabiera@google.com; h=from:subject; bh=B2kjYhFbSp4GX9YZwdN8eIiOyb3LTIyipZNOAiaztKA=; b=owGbwMvMwCFW0bfok0KS4TbG02pJDKk7ffM60yYd+Lhl7s6oww+lN4scPhCRv2uN2+mdVaHLu PJ04l7O7ChlYRDjYJAVU2TR9c8zuHEldcsczhpjmDmsTCBDGLg4BWAin98wMvyM+/HxveTGZr7Z eyfIn1z480L5hIvGsScvC7ZJfWF9X/eIkWGRTL7e9FreQ1I5WwubPlhl6tTz7xXsPbjTsi0ze9b XSbwA X-Mailer: git-send-email 2.43.0.429.g432eaa2c6b-goog Message-ID: <20240130192638.3557409-2-rdbabiera@google.com> Subject: [PATCH v1] usb: typec: altmodes/displayport: add null pointer check for sysfs nodes From: RD Babiera To: rdbabiera@google.com, heikki.krogerus@linux.intel.com, gregkh@linuxfoundation.org Cc: badhri@google.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The DisplayPort driver's sysfs nodes may be present to the userspace before typec_altmode_set_drvdata() completes in dp_altmode_probe. This means that a sysfs read can trigger a NULL pointer error by deferencing dp->hpd in hpd_show or dp->lock in pin_assignment_show, as dev_get_drvdata() returns NULL in those cases. Verify dp drvdata is present in sysfs reads and writes before proceeding. Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode= ") Cc: stable@vger.kernel.org Signed-off-by: RD Babiera --- drivers/usb/typec/altmodes/displayport.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/a= ltmodes/displayport.c index 5a80776c7255..0423326219d8 100644 --- a/drivers/usb/typec/altmodes/displayport.c +++ b/drivers/usb/typec/altmodes/displayport.c @@ -518,6 +518,9 @@ configuration_store(struct device *dev, struct device_a= ttribute *attr, int con; int ret =3D 0; =20 + if (!dp) + return -ENODEV; + con =3D sysfs_match_string(configurations, buf); if (con < 0) return con; @@ -563,6 +566,9 @@ static ssize_t configuration_show(struct device *dev, u8 cur; int i; =20 + if (!dp) + return -ENODEV; + mutex_lock(&dp->lock); =20 cap =3D DP_CAP_CAPABILITY(dp->alt->vdo); @@ -615,6 +621,9 @@ pin_assignment_store(struct device *dev, struct device_= attribute *attr, u32 conf; int ret; =20 + if (!dp) + return -ENODEV; + ret =3D sysfs_match_string(pin_assignments, buf); if (ret < 0) return ret; @@ -666,6 +675,9 @@ static ssize_t pin_assignment_show(struct device *dev, u8 cur; int i; =20 + if (!dp) + return -ENODEV; + mutex_lock(&dp->lock); =20 cur =3D get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf)); @@ -698,6 +710,9 @@ static ssize_t hpd_show(struct device *dev, struct devi= ce_attribute *attr, char { struct dp_altmode *dp =3D dev_get_drvdata(dev); =20 + if (!dp) + return -ENODEV; + return sysfs_emit(buf, "%d\n", dp->hpd); } static DEVICE_ATTR_RO(hpd); base-commit: f1a27f081c1fa1eeebf38406e45f29636114470f --=20 2.43.0.429.g432eaa2c6b-goog