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 4232A36921B; Sat, 12 Sep 2026 08:23:03 +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=1789201384; cv=none; b=XjGLHMkfgj5P8zY8pmw7fRGTgPngUvBrbPBLJnJPEWVp9+IYVqpo7BaFt6+luX0QEDYwjV0GGjppS9ortK/WcWDyONT+sfnlu/4nWk6jUjlSfxd3ZV1sQZnb01gRVn7Gob8+oJU7Ah/+O05xN0ymsN9OXo7KtR0TBnrjkVdV57s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789201384; c=relaxed/simple; bh=K8n03uwyjqHi+/e1GQ8d7ni5oo7nR6KLbCxonLnqAWA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=R4QIM+tw8zofAO0MN2vjjs7uV5mEzFkx1CZzHTcoWpxJVrKaJJNmWrWzzch4mqzywkY/lwZ3i7NzcLwjsi7cRQ9eUEC5KhvlcgHFut/Zx2EqrO4nXZznJG5kn0wbkQTHzTDicEq+fJbF/oI8UzOPzbBUwe988M+frSAcgG/c8vM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vNv0Y4MK; 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="vNv0Y4MK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D49081F000FF; Sat, 12 Sep 2026 08:23:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789201383; bh=7MLwPDE2hWzearVSYZ5tt8Ytit/2p6pYfr3WRh0QDr8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=vNv0Y4MKRoUysgMupAT31IsPdy/2nnBS/fNIQvVKcPwfWq/ADpIug83ewFYXWw6V1 gcGtbq1kvndlvXNC8dpcXJBQElVSTjFk62T8MZ+xdcZLQkSN4v963awXHbzQX+U9Is myjq+U3jLWsHprVMnaheX/6A10dpYCn709MT4o+k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gou Hao , jiazhenyuan , Madhavan Srinivasan , Sasha Levin Subject: [PATCH 7.2 0985/1815] powerpc/smp: add NULL guard for cause_ipi in smp_muxed_ipi_message_pass Date: Sat, 12 Sep 2026 08:45:35 +0200 Message-ID: <20260912065712.118149013@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065648.999753832@linuxfoundation.org> References: <20260912065648.999753832@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-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gou Hao [ Upstream commit 5aabc192702defb8950e7c81b05c3f4ca8ee43ec ] smp_muxed_ipi_message_pass() calls smp_ops->cause_ipi() without checking whether it has been set. On platforms using muxed IPI (e.g. powernv/pseries), smp_ops->cause_ipi is initialized to NULL in the static smp_ops and only assigned during the platform smp_probe() handler. If the IPI subsystem fails to initialize -- for example when xive_init_ipis() fails and xive_smp_probe() returns an error -- the probe handler returns early and cause_ipi is never set. Any subsequent IPI send (e.g. arch_smp_send_reschedule()) would dereference the NULL pointer. Add a NULL check to avoid the crash in that situation. Fixes: 23d72bfd8f9f ("powerpc: Consolidate ipi message mux and demux") Signed-off-by: Gou Hao Reviewed-by: jiazhenyuan Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260727104215.184786-6-gouhao@uniontech.com Signed-off-by: Sasha Levin --- arch/powerpc/kernel/smp.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 3467f86fd78f2..6a5a5469aaae5 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -289,6 +289,9 @@ void smp_muxed_ipi_set_message(int cpu, int msg) void smp_muxed_ipi_message_pass(int cpu, int msg) { + if (!smp_ops->cause_ipi) + return; + smp_muxed_ipi_set_message(cpu, msg); /* -- 2.53.0