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 7AF683B2D04 for ; Wed, 15 Jul 2026 16:32:30 +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=1784133151; cv=none; b=p78rs89AubvuZ+LqGugON3WCc9CJA+7OO7sEN5RwVEnn6+Z/SRqJirju9J6Va1wliFsRpng57KCjd6Yej06S1R9lRQCnGwPSNkf4tmqybCUg/1eA/YCUtdL/lNksXPynlE6y+aQctewMlGqkRp2vHRqh9bbF4Jg2X2ZEXrhdBfM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784133151; c=relaxed/simple; bh=qTXwCLEqv/IQ5hFQ+ddwAvb3/4aF1OqpZeppw0vcnV4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ru4PtLTq1R8cuq2HFcIjhZHC0tuApsqH1B6FjgPVyWuhTXfTl1uTZfcGN4/7tbaaFACoGRfsOFPfEHA+YL58HvTaPR1mUPbxDEmLY/NWXGEjwg99iEItIiOq9vYDepkJv+YhCLbQw9Xtx5YfnkFKsrIHCx3yxQ6rEf4b7U7spAA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KEgDE58R; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KEgDE58R" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E29BC1F00A3E; Wed, 15 Jul 2026 16:32:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784133150; bh=Gi5yX5BkgxDAu8wqQA3uIgWMaOdkDsiJ24p1mBwTl1w=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KEgDE58Rngg0d6EXq+bEo244gXS9BF2DGlNsT9Uf9kvRGfHkyxNuqdPe9e8KXGdXE dOYM8gYo8qxafbE+xJChdqLQBkz8voqCOErSC8WXLSq2fXW8xTdxN7ZcdcTG+/zSmX UsyZzBve3ZwOKxpgzBnVdW+0yWW7As3Nb3Y9nel+EPXfEWrOCufhMz6K7/Ukq+QV3L G3kAKUpXT0yOHvPcpIfu4j8l5vO6qDx/dXrgBjFdAJ75/n0D2uslCC2uprw823JlW3 Vtx0kJNpoHTJYecPoUt1D747zcXh9PESXvR8x8+Zd4FsY3lnalEUNmuj3p/ml0SI1q 88Ki5WvKazbWg== From: Sasha Levin To: stable@vger.kernel.org Cc: Marco Nenciarini , Bjorn Helgaas , Sasha Levin Subject: [PATCH 5.10.y 6/6] PCI: Skip Resizable BAR restore on read error Date: Wed, 15 Jul 2026 12:32:23 -0400 Message-ID: <20260715163223.952417-6-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260715163223.952417-1-sashal@kernel.org> References: <2026071318-kettle-cringe-5d1a@gregkh> <20260715163223.952417-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Marco Nenciarini [ Upstream commit ee7471fe968d210939be9046089a924cd23c8c3b ] pci_restore_rebar_state() uses the Resizable BAR Control register to decide how many BARs to restore (nbars) and which BAR each iteration addresses (bar_idx). When a device does not respond, config reads typically return PCI_ERROR_RESPONSE (~0). Both fields are 3 bits wide, so nbars and bar_idx both evaluate to 7, past the spec's valid ranges for both fields. pci_resource_n() then returns an unrelated resource slot, whose size is used to derive a nonsensical value written back to the Resizable BAR Control register. Bail out if any Resizable BAR Control read returns PCI_ERROR_RESPONSE. No further BARs are touched, which is safe because a config read that returns PCI_ERROR_RESPONSE indicates the device is unreachable and restoration is pointless. Fixes: d3252ace0bc6 ("PCI: Restore resized BAR state on resume") Signed-off-by: Marco Nenciarini Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org Link: https://patch.msgid.link/666cac19b5daa0ab0e0ab64454e76b4d24465dbd.1776429882.git.mnencia@kcore.it Signed-off-by: Sasha Levin --- drivers/pci/rebar.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/pci/rebar.c b/drivers/pci/rebar.c index ec449374291020..f0d3217841c0cf 100644 --- a/drivers/pci/rebar.c +++ b/drivers/pci/rebar.c @@ -130,6 +130,9 @@ void pci_restore_rebar_state(struct pci_dev *pdev) return; pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + if (PCI_POSSIBLE_ERROR(ctrl)) + return; + nbars = FIELD_GET(PCI_REBAR_CTRL_NBAR_MASK, ctrl); for (i = 0; i < nbars; i++, pos += 8) { @@ -137,6 +140,9 @@ void pci_restore_rebar_state(struct pci_dev *pdev) int bar_idx, size; pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + if (PCI_POSSIBLE_ERROR(ctrl)) + return; + bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; res = pdev->resource + bar_idx; size = ilog2(resource_size(res)) - 20; -- 2.53.0