This is a note to let you know that I've just added the patch titled
PCI: Release resource invalidated by coalescing
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-release-resource-invalidated-by-coalescing.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e54223275ba1bc6f704a6bab015fcd2ae4f72572 Mon Sep 17 00:00:00 2001
From: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
Date: Thu, 25 May 2023 16:32:48 +0100
Subject: PCI: Release resource invalidated by coalescing
From: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
commit e54223275ba1bc6f704a6bab015fcd2ae4f72572 upstream.
When contiguous windows are coalesced by pci_register_host_bridge(), the
second resource is expanded to include the first, and the first is
invalidated and consequently not added to the bus. However, it remains in
the resource hierarchy. For example, these windows:
fec00000-fec7ffff : PCI Bus 0000:00
fec80000-fecbffff : PCI Bus 0000:00
are coalesced into this, where the first resource remains in the tree with
start/end zeroed out:
00000000-00000000 : PCI Bus 0000:00
fec00000-fecbffff : PCI Bus 0000:00
In some cases (e.g. the Xen scratch region), this causes future calls to
allocate_resource() to choose an inappropriate location which the caller
cannot handle.
Fix by releasing the zeroed-out resource and removing it from the resource
hierarchy.
[bhelgaas: commit log]
Fixes: 7c3855c423b1 ("PCI: Coalesce host bridge contiguous apertures")
Link: https://lore.kernel.org/r/20230525153248.712779-1-ross.lagerwall@xxxxxxxxxx
Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.16+
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/probe.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -994,8 +994,10 @@ static int pci_register_host_bridge(stru
resource_list_for_each_entry_safe(window, n, &resources) {
offset = window->offset;
res = window->res;
- if (!res->flags && !res->start && !res->end)
+ if (!res->flags && !res->start && !res->end) {
+ release_resource(res);
continue;
+ }
list_move_tail(&window->node, &bridge->windows);
Patches currently in stable-queue which might be from ross.lagerwall@xxxxxxxxxx are
queue-6.1/pci-release-resource-invalidated-by-coalescing.patch
