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 B1BE93EC83A; Mon, 17 Aug 2026 15:20:45 +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=1786980046; cv=none; b=UmFZolWA4TqW2jUKozgoMs1d2O0TjmsNGVsInmKFEQqNLvNfmHFa4PsnWcT55YDFHb85AqwlYonAPtO8xkVB/ii3nQ9ZDbhXzzV+bVtZxaS3B7+9JGujsQcgRuWbwqN1shRtge95vDvvtm5LPNa4VPikwfqe1eMJJ4to5lfPwJY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786980046; c=relaxed/simple; bh=SSfmVpG0Amivm7nYSL/gzbpFc2+FBDeE7R2pbAMTtrQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=oq3Z9I6Pbom1ltXgAsCqNwZGWaoOPPAMYGwliVfUCoDiOQXlkV0SPCz9ciS6WD0LNOEKgX7kn+5rL1OpBQtHSxRz/Dn4zMOcN4tk08lNL1zhK7Lt/CxsoA1JD5vA0HCMZPFvDHdurXVuvypm+WPPUpcElXSYPyZlygCY6yS8HTc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QWi4P/US; 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="QWi4P/US" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DF20F1F000E9; Mon, 17 Aug 2026 15:20:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786980045; bh=0PlBQfwnfnhlLLBuRkipG0r0+h1hkphVzA8pprTvPBQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QWi4P/US4XLRaRb3riuIQgCUoy6HKgkCTUkt8fQAURARqfhmwPrH3xBHvLtr9pjZu 7vQv1RXqNU8EAyf/jV7gdOBLalaq5bTGQi8zMZxnrAeGqire0gZTyX/R6zjVwqsbZS wT6B7vtkZPFJg720+r0qCFVegNK9dXqCOZkPF43A= 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 6.1 436/609] s390/dasd: Fix potential NULL pointer dereference Date: Mon, 17 Aug 2026 15:32:12 +0200 Message-ID: <20260817132558.663717859@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132543.039278408@linuxfoundation.org> References: <20260817132543.039278408@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 6.1-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 @@ -330,7 +330,7 @@ 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;