From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794064639; b=xxBXzzziTHwxU3Q7KKGE/FLI52hyw4ufgGShZLvkuo5D4MQl8tXImoAf+0GFW7dOaFZ2 6d+ta4pDhBZSoTVhfmxL3AuSx0xQ/NARzbZ/jiGC9lvJehghNFbGg4ad1yD8WEwgzdAWn QV8+GaMrVs5reOIMbVxMKh5AvABsEyr0y1lr1Pk3uSM0yYH9ZBvn07zNQWR5rTeq6SHgi foM4yhdO7VY1u7k1HCRjhV2x+1Ncax/zzU6e9bDPrJ4WvI9VPClNMkRCJ/SY4t1OWeKNP aY7lVDRVLfbBWLvtIL+ugeIaeczetsZ3MZ2UPh6z0WnvIJ+8GU5iifleyY23GrFcWKw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794064639; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=rFAh4fhFgav3l7Sr3lLD1Nbowio+9qAvMvvM1T+luLA=; b=4QYLLVx2RBNjZFgu5l5On/4PuRUzb+UypVmNpWntmSt4zYtarZDqgDUjssZQhTRgT2KT EoVO86HcKCJqzYx4IOy/m3N2xA18CogInXjU3WRQsbiK/x/jVhqqV3L4/pvxWpyPpz0Dl gE55TA53FvdSOHymbZB1q5vXPGgLvmNNzALCuB7JRZbZ7c7lV352sjQsR6/m527VyswYi 0vFKcacKCXOepx2lpjC9VRBLaV+E2YKP0tNab6cMoixpVjP4APNxwQDksXXTFWhVFmsCM 74opjcBCSw17djDa+WSaBUXQ6sMejyd2ZIUidGo3Cjc++qPatF8Ul2i1JxW7tkM/swg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=0GOAlDWI; 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 1C3D2606A33D; Sat, 7 Nov 2026 15:17:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=0GOAlDWI Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE6DB1F0089F; Sat, 7 Nov 2026 15:17:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794064639; bh=rFAh4fhFgav3l7Sr3lLD1Nbowio+9qAvMvvM1T+luLA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=0GOAlDWIdrPoLCm6sndy8i+dDxyqU8TAqLIZQvBAp3sw2T7xAHqaX0FXeYbtKcpjj sJkMGk85GTmvjvI5MWTLk6RYQRLTIsrZXCnUkMaoX5iKIUty3XcBQw2WhrYVNmfXfd i+np0epbGNl5UyqwWoGZLOxtXypysDoQSWbty5Zk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Qu Wenruo , Hengyu Liang , David Sterba , Sasha Levin Subject: [PATCH 7.3 0644/1257] btrfs: return -ENOTTY for unknown ioctls on the control device Date: Sat, 7 Nov 2026 08:49:00 -0500 Message-ID: <20261107134957.060886575@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134939.434104957@linuxfoundation.org> References: <20261107134939.434104957@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hengyu Liang [ Upstream commit 9985f1643ac3f8595862e2f82108f0ccae4cf959 ] Commit 5ab2b180884c ("btrfs: factor out validation of btrfs_ioctl_vol_args::name") made btrfs_control_ioctl() store the result of btrfs_check_ioctl_vol_args_path() in ret before it looks at the command. However, ret is initialized to -ENOTTY and the switch has no default case, so this initial value was what an unknown command returned. As of now, every unknown ioctl on /dev/btrfs-control returns 0. A tool that tries a control ioctl which the running kernel does not have is told that the ioctl succeeded. The issue can be reproduced with a simple C program, run as root: #include #include #include int main(void) { static char buf[4096]; int fd = open("/dev/btrfs-control", O_RDWR); if (ioctl(fd, TCGETS, buf) < 0) perror("ioctl"); else printf("ioctl succeeded\n"); return 0; } Before commit 5ab2b180884c ("btrfs: factor out validation of btrfs_ioctl_vol_args::name"), the result is: ioctl: Inappropriate ioctl for device After that commit, the result is: ioctl succeeded This patch will add a default case that returns -ENOTTY. Fixes: 5ab2b180884c ("btrfs: factor out validation of btrfs_ioctl_vol_args::name") CC: stable@vger.kernel.org Reviewed-by: Qu Wenruo Signed-off-by: Hengyu Liang Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/super.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index ddb620ac241b4..2c9b29aa59a2e 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -2305,6 +2305,9 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, case BTRFS_IOC_GET_SUPPORTED_FEATURES: ret = btrfs_ioctl_get_supported_features((void __user*)arg); break; + default: + ret = -ENOTTY; + break; } out: -- 2.53.0