From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1ECD633DEFE; Fri, 7 Aug 2026 15:10:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786115429; cv=none; b=Ldyd43HrFm2ox1Nsbv5XDvIUP6zPXSW5R2XepSE4OcjJt7yigAoW1kNtcILFUsB2pnV6fhB4d4kowLYEySQvW5HzE0RBLkZ4NlhDE64X4xAIQ/ofNmvAkeC5FoN75BSPAe//NdKRo2lVXMTZFkw+zoBwX8VSMTDHZK2nwZYRVNc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786115429; c=relaxed/simple; bh=/YYfGoiDFrmHLm0lORHceMs7+aA5mtOKP5Zr1/XqfgM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=q3CtyWkQI3QZp8BORr2melikEOxcH8vJa65Cn+nqIkzLLL/TRfbEpTRx7XqIaVI9XpP2MVpDjGFlHSuZFu7k2xIrkKdlmYK+a+numZj44MD8Oar5zRlu7zW9JhuiRnMEdZur7RfrWw2rY/ZzPPFem4oLkanPeAr7UTkswn0M6eM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gaiSB8gf; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gaiSB8gf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6FE8B1F000E9; Fri, 7 Aug 2026 15:10:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786115428; bh=hOW3wmJKSggPL05NaBZ/ME1paNcuAZfSVqwg+mo26wo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gaiSB8gfuVCq0vgPeECuJ2A0IWafy64k8JjOQA5yiyPA0IECNcknpNl7P8fCQTFFn Dej6mSQULDHJY20dkb+fPKTSnpolC/QbgB2dm2xxeOULUM+zGb9ucF6rR++f19NqbC GtPJ1ur71fPiUQfM3v2UDMGcxsegfbxqf2cUikPQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Vasily Gorbik , Eduard Shishkin , Stefan Haberland , =?UTF-8?q?Jan=20H=C3=B6ppner?= , Jens Axboe Subject: [PATCH 6.18 272/396] s390/dasd: Fix potential NULL pointer dereference Date: Fri, 7 Aug 2026 16:37:12 +0200 Message-ID: <20260807143430.122027480@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807143424.272339768@linuxfoundation.org> References: <20260807143424.272339768@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan Höppner commit 9973026f572db6b67570cadc30942f3014e41079 upstream. dasd_release_space() checks the implementation of the is_ese() discipline function before calling it to determine if a given device is an ESE DASD. The current usage of the logical AND operator will lead to a NULL pointer dereference as the function is called even if the function pointer is NULL. Fix this by using the logical OR operator. Fixes: 91dc4a197569 ("s390/dasd: Add new ioctl to release space") Cc: stable@vger.kernel.org # v5.3+ Reported-by: Vasily Gorbik Acked-by: Eduard Shishkin Reviewed-by: Stefan Haberland Signed-off-by: Jan Höppner Signed-off-by: Stefan Haberland Link: https://patch.msgid.link/20260727142840.567286-3-sth@linux.ibm.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/s390/block/dasd_ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/s390/block/dasd_ioctl.c +++ b/drivers/s390/block/dasd_ioctl.c @@ -325,7 +325,7 @@ out_err: static int dasd_release_space(struct dasd_device *device, struct format_data_t *rdata) { - if (!device->discipline->is_ese && !device->discipline->is_ese(device)) + if (!device->discipline->is_ese || !device->discipline->is_ese(device)) return -ENOTSUPP; if (!device->discipline->release_space) return -ENOTSUPP;