From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f182.google.com (mail-pf1-f182.google.com [209.85.210.182]) (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 9C93944AB77 for ; Mon, 17 Aug 2026 16:09:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786982983; cv=none; b=FrjyKWS1pwd9jcb7IfQUS087Czs5iI5n4upgXpjbQPZywfrEgJSTG+w1Vbl0sQsMrqXSeqHofF0QSIrP7efXApoUuHsiXhSFA0/D0xZG4Y+3lPP+ZX+jVX0Q8n2IhuUbyW47xGVrzCpods+hbweOWhwYMpam0Hx7bwNiJ4MoKhI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786982983; c=relaxed/simple; bh=3ioQTCR6NPmKcAUQa+YGkAxDVioWSRJMHck+2juAYqg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Q9y0aq1I2YuGsJNNHDfhkc2DrBFgS496zAmc2HSjC4DQDo97hPVZFpLkaChIOg96tBpxLgnsFI6bkyVisax6nVbL7NlSUGiaKmafiLbwTUKY61qF3xXGaK9z1LHY/LXAb8TZx/qC5bKOStT6wA3eVpuv4ac7QtJ0SV/TIpRZkS4= 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=b1Cs/tck; arc=none smtp.client-ip=209.85.210.182 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="b1Cs/tck" Received: by mail-pf1-f182.google.com with SMTP id d2e1a72fcca58-8485b358552so786041b3a.2 for ; Mon, 17 Aug 2026 09:09:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1786982978; x=1787587778; 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=WC5+Xv8TC0JCUAachW4xnIwZrYhT5/dH1idLAYXXfSU=; b=b1Cs/tckyThGTz57h0yhpG5rYibcPz649vkLjnKqEY5xmCicrGBtI5GueaiL0CHqDn GqlDPPC0QWAJmXOqGlWkBH37HTt0PvcqO6OyUYVlE/z+4mJ+0KofNft0vanxOF0RyyDP jqOrFed8NDGBUye6f7Ph73KcSwkQtAnN/ieXKaaXQC2/Un9eYkdY9TSjCOF38aCvDZbe ZmneUQf9YVQ3AI97Sm4LTdINC9aWiFgRytxms2fh1TxkQj1HWn6z2OthC9p9ehJTj5eF kLBsTrXc78dYYeB5WYmAp/fUWrEv7GHXlyFwQDaEzS3C+6Ku1BSgAwnm0bJnAG2gzsm4 7pnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786982978; x=1787587778; 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=WC5+Xv8TC0JCUAachW4xnIwZrYhT5/dH1idLAYXXfSU=; b=U34qjuOOOXJ3NEPO/p4XBxvftifnEygUz5jRmLcO4QTSxiYKEyKWLkudncnw7X6AB/ FrN3abttetnTCxjCroumhyOMpaoXN8FmaUOOfNtbwv0fi1ITbEbUmB80kYa4gWLG2M3A LtF3IhvK8CeKLF8zU9ZG79EIrFHU0pzfW/92yNRChJ6zmsySuSOHC39RCPhoCnFF0vbg q85IIau92Tt9y/57pmAbn0+fANdeuKhytJGMbynqFf7D9uw6UV0YAvJY0M+0/bVNI5/r ycJSQ9lhStbnT37yeozuHx6ijylDlBZh0CeHxR9yYwqsp357SLkwSaVTSBsGJT76XFMt Tiiw== X-Forwarded-Encrypted: i=1; AHgh+RpiwMhe2znBbOZGjBHZJ7aodXp/fnfwtesuIE9K5SWyY2nlNyfgcBHGoyXMpzSvZUN78yEdlF1XvxE=@vger.kernel.org X-Gm-Message-State: AOJu0Yy4Pwh51CkkCPNaHqNMLuUabMsptea/t9f8tqgZGfOmKFN0xmJ3 TZ2C5cLv9zsuASKX1gLX74ZZU0ao0+TZbSQch/2Mel9JiwvWV5QA9EuB X-Gm-Gg: AR+sD10+x2heeVscVQfUuAYc2FnJgrVOBQRmrOTgojE+RBxsaVlxIrfOJRf7mHr1JsU khxK9kt0MOX49jA46hBmlEEmWE65wdLANaXuox0oKCzStP4w3lzP85uVsO3AgJLIHk6nodfMFQh Z1OkeF96WDTMA0GfWL6+vL5Uf6ZZvylHnd4Jx6rJi4JQxNiC1shRL5np7QN1jzJVJmYY3w7f8Xk 3Bl39QufJZvJO/ZV0OElmJC20qYEsUiYj5IgvjXcv3JiODlgcAAcQT98zGFgkDQ1HzC78wBPk0k iKW1PpQKEsp/yumDC0dlYV5kp2sQ1lWE0OgpLiYVuZWV0lc/pe06ICht3HQ/62BTS6I0R3Wlnnz e28LaBZsOq2milQ4mmJ9kW5kDqjEiew0QK4hGrtO+hGiCLpJ531wIYhzEgoRq8wktQ1tzqRiEF1 3ndDK3o/CiqcECTEWE3QDmQpRznlpa+WEJ9M9uSnd0xb4iLJhfbfR4YvApaOx4iJjH993phCaWL lJg X-Received: by 2002:a05:6a00:4186:b0:847:82db:9046 with SMTP id d2e1a72fcca58-851b885b6f0mr1776047b3a.26.1786982977545; Mon, 17 Aug 2026 09:09:37 -0700 (PDT) Received: from Default ([2409:40f4:103f:ca54:3a70:ebd6:25c9:29fd]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-851b4074d41sm818063b3a.27.2026.08.17.09.09.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Aug 2026 09:09:36 -0700 (PDT) From: Jeffin Philip To: jeffinphilip14@gmail.com Cc: christophe.jaillet@wanadoo.fr, felipe.balbi@linux.intel.com, gregkh@linuxfoundation.org, kees@kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, stable@vger.kernel.org, stern@rowland.harvard.edu, syzbot+791be35f1fbcc85d06d7@syzkaller.appspotmail.com Subject: [PATCH] usb: gadget: f_mass_storage: fix null pointer dereference in fsg_common_set_num_buffers() Date: Mon, 17 Aug 2026 21:39:16 +0530 Message-ID: <20260817160916.28523-1-jeffinphilip14@gmail.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817160319.28251-1-jeffinphilip14@gmail.com> References: <20260817160319.28251-1-jeffinphilip14@gmail.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Mon, 17 Aug 2026 21:33:19 +0530, Jeffin Philip wrote: >Kconfig currently sets the limit from 2 to 256 with default as 2. However, >we use that only at build time. So, if we enter during runtime via configfs, >we set page content to 0\0 and get the null pointer dereference. So we will >need to add the check for num < 2 in fsg_opts_num_buffers_store() and return >EINVAL? Upper bound is 256 which is below what kstrtou8() can return anyway. Correction on the last sentence: Upper bound is 256 which is _above_ what kstrtou8() can return anyway.