From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1B17B2AF07; Mon, 28 Oct 2024 06:52:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730098346; cv=none; b=WEz3p3ujpQyG4MwD3zL0dUtJKFKYgyjrPpvfBRuUZu3D6MkaNG9yfFyvMj71h9mgPfQu6CEyOn97KLMR3LbpkJSy+lLyxLwle13LFaEcADs6pGii+r4eDWfpG7QKcmU9cDGEzbiI3ocjSjmtGBlrA1BJPd9j3ky0+7TkMOD/VV8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730098346; c=relaxed/simple; bh=f2TG4ivWerYv6kBndIV6XhLX00vW56oLW9X9YvInfkM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Yr4WaClxSQnRnZOGXWCLO+ore052pJY/+q6OXWfk2Xccf7PKzTwotlBI5F6pTynWLBc/AjNUcdxXxQl+4O5cj5CMaYwSHE+sPVhwrnXdCaKVMz8fGDr+CkilFKoxP4dR6pOa2rnKHazuH6QEBkYoU3iyxQSq9X2kS7oTMflkdcw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gppAdYAt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gppAdYAt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 57C87C4CEC3; Mon, 28 Oct 2024 06:52:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730098345; bh=f2TG4ivWerYv6kBndIV6XhLX00vW56oLW9X9YvInfkM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gppAdYAtbsKdrLeZtWPE/PTJR2XEdoZvGf3tAKNk+SR+WSMhJV39hICS/lCxZF4C/ 9y59gMEoEPTw/6Dvm3xeqGk6XjMmPGQ+CAZqsoB5h9+lAPQRv/aWJ36hFcx6DmKdR4 RnA0OFW4/KltL4hNoDiKdKWuIYOsRuIznu0ktCOM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Konrad Dybcio , Bartosz Golaszewski , Bjorn Helgaas , Manivannan Sadhasivam , Sasha Levin Subject: [PATCH 6.11 187/261] PCI: Hold rescan lock while adding devices during host probe Date: Mon, 28 Oct 2024 07:25:29 +0100 Message-ID: <20241028062316.704411200@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241028062312.001273460@linuxfoundation.org> References: <20241028062312.001273460@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bartosz Golaszewski [ Upstream commit 1d59d474e1cb7d4fdf87dfaf96f44647f13ea590 ] Since adding the PCI power control code, we may end up with a race between the pwrctl platform device rescanning the bus and host controller probe functions. The latter need to take the rescan lock when adding devices or we may end up in an undefined state having two incompletely added devices and hit the following crash when trying to remove the device over sysfs: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Internal error: Oops: 0000000096000004 [#1] SMP Call trace: __pi_strlen+0x14/0x150 kernfs_find_ns+0x80/0x13c kernfs_remove_by_name_ns+0x54/0xf0 sysfs_remove_bin_file+0x24/0x34 pci_remove_resource_files+0x3c/0x84 pci_remove_sysfs_dev_files+0x28/0x38 pci_stop_bus_device+0x8c/0xd8 pci_stop_bus_device+0x40/0xd8 pci_stop_and_remove_bus_device_locked+0x28/0x48 remove_store+0x70/0xb0 dev_attr_store+0x20/0x38 sysfs_kf_write+0x58/0x78 kernfs_fop_write_iter+0xe8/0x184 vfs_write+0x2dc/0x308 ksys_write+0x7c/0xec Fixes: 4565d2652a37 ("PCI/pwrctl: Add PCI power control core code") Link: https://lore.kernel.org/r/20241003084342.27501-1-brgl@bgdev.pl Reported-by: Konrad Dybcio Tested-by: Konrad Dybcio Signed-off-by: Bartosz Golaszewski Signed-off-by: Bjorn Helgaas Reviewed-by: Manivannan Sadhasivam Signed-off-by: Sasha Levin --- drivers/pci/probe.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index e9e56bbb3b59d..d203e23b75620 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -3106,7 +3106,9 @@ int pci_host_probe(struct pci_host_bridge *bridge) list_for_each_entry(child, &bus->children, node) pcie_bus_configure_settings(child); + pci_lock_rescan_remove(); pci_bus_add_devices(bus); + pci_unlock_rescan_remove(); return 0; } EXPORT_SYMBOL_GPL(pci_host_probe); -- 2.43.0