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 BA01737E2E7; Sat, 12 Sep 2026 12:43:40 +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=1789217021; cv=none; b=u5H4q2LePBuFuyMd3Kz1sW1bsIqwuiFQfLGD8EJNsZExkMNd8nSKKmCvVAd7IYjyUZtJfVwgbfxgYMg0/4X9p3yl8x0P06Ec801h35t96eyyclw30W8cdCYHzCG/ipeWs+NpQBm4LmnWmdRMIKnJnaNj90kALAj/DVdOmnd2Ers= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789217021; c=relaxed/simple; bh=mHH8hwn0oidFxhNbamtr3w0gJE5DtIIkYXEhZkmBodY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aeM0vUYGFhKK6Whlb7KOclS1+vg62WD9oKVb6MK1/M0RdXaJDF9yVaXm0hXP54rmKrsFNilYQBNwvtbNQKPQAQA127tweWGOppYWTaYybBq3XfiiZf2xxZ9B7lo9XQl8cefTeoa859aXZf1pwMB8FYjB8oUQKM015oIO2TY/26c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WSuEROKV; 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="WSuEROKV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7346E1F000FF; Sat, 12 Sep 2026 12:43:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789217020; bh=q0McLJYVHImiwlaE7dcar+jV/t3nqPxYmMS+xdHCOPk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WSuEROKV0JGeVyOEMZOjGPjjoAUCWfED9RikkPMwkr5THtTTo+/hIFdF5dciDUoQa H96APDzkxgdICmrEexVLLdxAUvYvqkoxAhvoMB8o5IjKCqsHa+GwLglPdAYissKEWQ RzURN5BEiK4zBdR49kAq/EakQKsr7/XZ9vS82tcA= 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 6.12 0856/1376] powerpc/smp: add NULL guard for cause_ipi in smp_muxed_ipi_message_pass Date: Sat, 12 Sep 2026 08:54:42 +0200 Message-ID: <20260912065626.639515569@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.535295758@linuxfoundation.org> References: <20260912065607.535295758@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 6.12-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 09b2ccf387118..6bf939d15f1f5 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -288,6 +288,9 @@ 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