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 C17541FC110; Sat, 12 Sep 2026 10:41:03 +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=1789209664; cv=none; b=AG9y2VFvyCacIoRzacgerERjHTCymwRg8xaM7RbC+4aO7rnktOkpPEoFcNEwZE6gQ94oChQ5p7GL68RMLRpPMendUoz3fZLbO4o0nyttIFRJT1vbZfN+cuu/kXv15YH+ieDjbqKAXbmdcqb3cXv5436DgwJETCHiKoXLLt1ZAEc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789209664; c=relaxed/simple; bh=OOJ2VcrFivHie2ycSEqJ8tFMeMDPpyCgvBhAA8x1hME=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ckBBtT9FtelX6NFL08c1UpL8tb8xrSt8AKV+qeSa3mmS60IRU9HqH3DG9p9C2Gb93XaUeWJMorUM8z7yM9lt6QNHUelWUMx91zn4MFNpBZqStZxSGB2HLVaksQk85Mzu+dRw9WYFmREZD/JzGsk/17dBcY0qqlT8jsr8LrBAv64= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mXO11E3l; 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="mXO11E3l" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93A861F000FF; Sat, 12 Sep 2026 10:41:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789209663; bh=P7NbRw5rObm+ZI6afXf5grvHogpRWhtI34CEX9Ik+r4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=mXO11E3lexPfhlklJinZb6gMQZ8oysAHb35KHTqVT2KdRZs430RcNhK7/ZxU3qJzR ZYFcwFn0WdLY0nMwPbsatJbd1hKisttgciaIB4ARKIYSaruwsfFseVqz5qHiPupGtK aFkbPMIVw1ho8k3aWax4JIjUlw5wt1J8bxGD2scc= 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 6.18 0830/1518] powerpc/smp: add NULL guard for cause_ipi in smp_muxed_ipi_message_pass Date: Sat, 12 Sep 2026 08:49:59 +0200 Message-ID: <20260912065642.215752393@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065623.398859879@linuxfoundation.org> References: <20260912065623.398859879@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 6.18-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 0cd9c0c21af3e..b5518fba3b92e 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