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 373CB3242D4 for ; Wed, 15 Jul 2026 02:46:06 +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=1784083567; cv=none; b=h9lP6pACc0soH8IDLsgK5ux6jQHq8CV/+hahaSgtPl30LN3EbqYVssl5PTz0o60qO4nXi1NJJ4E/qk4nD6jBNBRqRqw8DPIra/UEbW/NyGe8ThSbKiyYPhW6ySeqQszzevD+B5Jm8sG8npaLzmSWvKG5Z/zyiEN/swizEpX38PU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784083567; c=relaxed/simple; bh=lAlKAZPaU/kgZP97rXAB7lqeqfWIPIRXZ0tIu96uRbw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WF3o5DmYX1gcfcT5gEqB3qboF/XaUahgB+FodRN+DKxkEqBxb4fmpShx43m8VOtH5vv4Wn7ThUzlWnhok3swoa2O6xoZI4OrFSduV0WrjSluAPlAANo2W82pOcB2KbIp0YwueKTmhc85G2gQodzt+dfetxIZ8dI1fa25dtHEJ14= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=C8vIa5p2; 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="C8vIa5p2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E0841F00A3A; Wed, 15 Jul 2026 02:46:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784083566; bh=rwFCscdxx1zTtymWK4XKX49skULgpl7IMt5Wxc3tnNI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=C8vIa5p2NtTM3B389f7h2m0XD3deEAZxWgiQkwIbhP4X7lq09whK0qze8pFP763bh HqNvKF9Dv0nDPJ9O8GGFDqx9Ig6ct5I5vHGUquEnoeA/T+W1zwQ9Qw7Z4vFnJ6kXYN wt71YH2mHPmrvGHX3e7pLghAdOOuiks/2ShomAoZM+iaXM9MoFV+8E76GAuqJYD43L EAKwyxRrMm6wquEnVu0PBfCMZ07BscR8x1ncE9GN3lx7YG1d90z9mbgL9fbrzF2Vi2 VAIWlmq1e2ZD4nkLw2YSqDuvKwvFQYrPpS3EdCJCKfoVUdsKm+liNhlzu5DEbXsQ2X LixiMgNPix2Og== From: Sasha Levin To: stable@vger.kernel.org Cc: Marco Nenciarini , Bjorn Helgaas , Sasha Levin Subject: [PATCH 6.1.y 6/6] PCI: Skip Resizable BAR restore on read error Date: Tue, 14 Jul 2026 22:45:59 -0400 Message-ID: <20260715024559.106836-6-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260715024559.106836-1-sashal@kernel.org> References: <2026071309-opal-shaking-a4ea@gregkh> <20260715024559.106836-1-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 4373cd796ae99b..920ef3ab4bda35 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 = pci_resource_n(pdev, bar_idx); size = pci_rebar_bytes_to_size(resource_size(res)); -- 2.53.0