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 28D9D41A903 for ; Wed, 15 Jul 2026 11:16:25 +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=1784114186; cv=none; b=J8PWfGLEvehO04N0uRkf7mXn3Fgj5KjDz0tzd6WiLjF11b277rhV21q8dgYRIgWg2ZKmc6hqpD2YCWHTTCWcCFNod14o+FZCzlxvPn8Etae0m//VKv3yjidHaFp9qebZg9cRmzHmr7uq4JNnCSeSzymyh3jWo/+LkjniCWhKl9U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784114186; c=relaxed/simple; bh=8au4cYz3SjqaNkdSFgEgRmD7D8xS1kQVhbYS0wI2adA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DsMqQh3RHfdyKeW+ghF6Rs7ODXEB60fBkBkrTqwGquigVYnLcP82DB12vwqjxhYbBIbuYZU/fAN+7XmNmCaaiBYF551Z6CfRHW7nLkXECO9h1PqAP8TskQGAASfVyy/Y50xx37bNG0UW2fjItLDJtCS5sGU6EXaLAwqMhv33P4A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bvvI90HZ; 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="bvvI90HZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90A031F000E9; Wed, 15 Jul 2026 11:16:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784114185; bh=AXA9EnA2jvPUUM7HKiFzOIAT6uUlV/mN6uJt3mHalnM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bvvI90HZHS8AsBVxwLx/FPsCX8OPigWUWPGroiJsDZkHlGnFggAfabj9Yr6Un6Ycd JWHl2IHFJfxfTIeN4eUbK9U9okzJ/SOe5JwTS10PrWz1D78OwR25UY6I1y8/v4YTAs UlRiyaZz4Ctd3fgO7iOhWrQk5wRCq2hyQQ1LhuoQojA/M8qCHrLiEbA9s8JjbW2bcK gTcPjlZL9x1+kkemBU/eXO8bWaSkW3GsRrD5fAMSU4RuTXBsjHvFm7nwujwNLJP3zX PhEu8yXHpT+55TRlp1OnVBYSVVBi2aC0di/vD6zhUkk7IKlHO0uquv0YA7AN4aCzdB 9hTI9jThg0wew== From: Sasha Levin To: stable@vger.kernel.org Cc: Marco Nenciarini , Bjorn Helgaas , Sasha Levin Subject: [PATCH 5.15.y 6/6] PCI: Skip Resizable BAR restore on read error Date: Wed, 15 Jul 2026 07:16:18 -0400 Message-ID: <20260715111618.647249-6-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260715111618.647249-1-sashal@kernel.org> References: <2026071314-tableware-flashback-79cc@gregkh> <20260715111618.647249-1-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 a10d264a7c77ea..02ad0ed8311c4a 100644 --- a/drivers/pci/rebar.c +++ b/drivers/pci/rebar.c @@ -131,6 +131,9 @@ 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) { @@ -138,6 +141,9 @@ 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 = pci_rebar_bytes_to_size(resource_size(res)); -- 2.53.0