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smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Lt+YaIK4; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1B8B76082BFE; Wed, 4 Nov 2026 17:49:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Lt+YaIK4 Received: by smtp.kernel.org (Postfix) with ESMTPSA id DEBC01F00A02; Wed, 4 Nov 2026 17:49:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793814579; bh=WXeWRtHDTvlcvQqGcGXKpHSOkC75TIYAS6cttW7V/+A=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Lt+YaIK4iwvhO88yz6f+jCVQ4EeVtRm3q99whbt1o/jNi7xtD4GqEdXZoJFzfX6Mp WhMZbYdWqf2DxTyriqyK8bk+1pkoMOeKNlWc1KnsmnTw9VPIopuCsvCi1M52TYyyYy mLRpfJ5+g7TTPX7fTPYeQh+RWFIoWO07NXukL0yXrI10YEQ4gET0I5LF9DVoDQmUfc lxhs2rswNnIdaIHeRhuWnBLDBlekuRGf9w/PHx4KPTJhR73a5GVIB+8eRNFo3DUyff XmvJcy95iTPua8zzn9tBaoG3qUN1vOZ1Duxa0Dj2HpRO0snpxh5ps1EWgqor16H8rg xLTK+rVahkKTw== From: Christian Brauner To: linux-fsdevel@vger.kernel.org Cc: Linus Torvalds , Jann Horn , Josef Bacik , Chris Mason , Jeff Layton , NeilBrown , Eric Dumazet , Thomas Gleixner , Al Viro , Jonathan Corbet , Christoph Hellwig , Greg Kroah-Hartman , Joel Granados , Kees Cook , Jan Kara , Jan Kara , linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-um@lists.infradead.org, linux-wireless@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, ntfs3@lists.linux.dev, platform-driver-x86@vger.kernel.org, coreteam@netfilter.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org, linux-sound@vger.kernel.org, netfilter-devel@vger.kernel.org, dri-devel@lists.freedesktop.org, ibm-acpi-devel@lists.sourceforge.net, jfs-discussion@lists.sourceforge.net, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-cifs@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-mm@kvack.org, linux-sh@vger.kernel.org, linux-usb@vger.kernel.org, samba-technical@lists.samba.org, sparclinux@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-doc@vger.kernel.org, linux-serial@vger.kernel.org, linux-atm-general@lists.sourceforge.net, Takashi Iwai , linux-input@vger.kernel.org, linux-raid@vger.kernel.org, linux-ext4@vger.kernel.org, linux-modules@vger.kernel.org, linux-debuggers@vger.kernel.org, "Christian Brauner (Amutable)" , Chuck Lever , stable@vger.kernel.org Subject: [PATCH v2 18/51] platform/x86: toshiba_acpi: reject malformed brightness and fan writes Date: Wed, 4 Nov 2026 18:47:04 +0100 Message-ID: <20261104-work-procfs-bugfixes-v2-18-bbf7d5546809@kernel.org> In-Reply-To: <20261104-work-procfs-bugfixes-v2-0-bbf7d5546809@kernel.org> References: <20261104-work-procfs-bugfixes-v2-0-bbf7d5546809@kernel.org> X-Mailing-List: linux-modules@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" X-Mailer: b4 0.17-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1850; i=brauner@kernel.org; h=from:subject:message-id; bh=dBPyRrfA4AE5uU+SDwP01KQAXBYhly7L9ZsRpXHhzrM=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWS9zruys4H5zATJQ56FL4QUZwrEz3fqPb76g29l8a1fL 34Us/t+6yhlYRDjYpAVU2RxaDcJl1vOU7HZKFMDZg4rE8gQBi5OAZjIpPMMf0V6J05hXXkg4U7m Il2PkyIVrevVp6rG3zbnfJ6waxtPdw/D/+K7i173sLVVenL7Mu5oFdvPFn8nM9t33dyDiXp7bPP NWAA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Content-Transfer-Encoding: 8bit When lcd_proc_write() and fan_proc_write() were refactored their checks were inverted but the && stayed. They only fail if sscanf() didn't parse anything and the value is out of range at the same time, and for the brightness value < 0 && value > levels can't be true at all. So an out of range brightness or fan setting is passed on to the hardware, and so is the uninitialized value if nothing could be parsed. Restore the checks as they were before the refactoring. Fixes: e1a949c1b988 ("toshiba_acpi: Refactor *{get, set} functions return value") Fixes: 3e07e5baa2af ("toshiba_acpi: Add set_fan_status function") Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) --- drivers/platform/x86/toshiba_acpi.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c index a0b8060836d0..9eb8f1e5aeda 100644 --- a/drivers/platform/x86/toshiba_acpi.c +++ b/drivers/platform/x86/toshiba_acpi.c @@ -1498,8 +1498,8 @@ static ssize_t lcd_proc_write(struct file *file, const char __user *buf, cmd[len] = '\0'; levels = dev->backlight_dev->props.max_brightness + 1; - if (sscanf(cmd, " brightness : %i", &value) != 1 && - value < 0 && value > levels) + if (sscanf(cmd, " brightness : %i", &value) != 1 || + value < 0 || value >= levels) return -EINVAL; if (set_lcd_brightness(dev, value)) @@ -1678,8 +1678,8 @@ static ssize_t fan_proc_write(struct file *file, const char __user *buf, return -EFAULT; cmd[len] = '\0'; - if (sscanf(cmd, " force_on : %i", &value) != 1 && - value != 0 && value != 1) + if (sscanf(cmd, " force_on : %i", &value) != 1 || + value < 0 || value > 1) return -EINVAL; if (set_fan_status(dev, value)) -- 2.53.0