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 75DAD1E5B68 for ; Wed, 15 Jul 2026 00:18:02 +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=1784074683; cv=none; b=C+njU2eD6i0dyRnnZ0c4tRLi4yjeZgyUvoJUkUGt7e/ps5i8+Ozwwhk4kFlFey+FgUHXyhZwkUzLrS+L8Le1RpMjbtU3j5f9E7MM8UcAziFfZjNdfn9Uk/a7ukIxHlYIrPnI0KV33KoSwFYzzsTQZDrOXX//PbfWJlPVZDPKtMo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784074683; c=relaxed/simple; bh=lAlKAZPaU/kgZP97rXAB7lqeqfWIPIRXZ0tIu96uRbw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tPkYTiAC7qno3N3Y05/lF/hztdu9f4Bnr2+c0PrBDjcEvaA2zHXDnoNWOyaIcNyKA+QQmobkPezRB2FjK85I5AFuYRIQ78Olv7mJg45XAOHhJamhxXJGr5Y+tNCLTgpG+fxefQNr5awTftwt5DxHgt8oOB4+31QFjsvAb1iXjJA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=H0Dsw2Dl; 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="H0Dsw2Dl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E33031F00A3E; Wed, 15 Jul 2026 00:18:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784074682; bh=rwFCscdxx1zTtymWK4XKX49skULgpl7IMt5Wxc3tnNI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=H0Dsw2Dll0G10t7fwKnp+CKhqd2tIXw0RXsXZOYtOEgUsoDFFi/wrWP3s8xO5yX9O blFyA4z4RAY8MFhqd2zlKRr0kpKAsbIFjeGJ+A74mtDtK/TtYjxvzY6TcmYBGtwffz g5B+XAru+J+iMlHRDXY7lRxZuuJ/DfN7kGUZX/3k4y7FrabHwvLc/QSYhE1UYvDR1U LM+JFlCQlP4/ohaqeb6MmPM72FEdp4ms9wlLKVKthhNp4PZdqXB7mYkAZvH76aHUbQ acJ8zlidfpCaGaSZtgwZ4Hp2hZhtwX+WNHJzNcZxnYui+4rFq6Ddp+5DMHdyU6v41A kxg38Obhx20hQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Marco Nenciarini , Bjorn Helgaas , Sasha Levin Subject: [PATCH 6.6.y 6/6] PCI: Skip Resizable BAR restore on read error Date: Tue, 14 Jul 2026 20:17:56 -0400 Message-ID: <20260715001756.3783927-6-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260715001756.3783927-1-sashal@kernel.org> References: <2026071305-gulp-reenter-fa22@gregkh> <20260715001756.3783927-1-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