FAILED: patch "[PATCH] vfio/pci: Release the VGA arbiter client on register_device()" failed to apply to 5.15-stable tree

FAILED: patch "[PATCH] vfio/pci: Release the VGA arbiter client on register_device()" failed to apply to 5.15-stable tree

[gregkh]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x daedde7f024ecf88bc8e832ed40cf2c795f0796a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026071318-parasail-contents-0b7a@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From daedde7f024ecf88bc8e832ed40cf2c795f0796a Mon Sep 17 00:00:00 2001
From: Alex Williamson <alex.williamson@nvidia.com>
Date: Mon, 15 Jun 2026 13:12:30 -0600
Subject: [PATCH] vfio/pci: Release the VGA arbiter client on register_device()
 failure

The re-order in the Fixes commit below displaced vfio_pci_vga_init() as
the last failure point of what is now vfio_pci_core_register_device()
without introducing an unwind for the VGA arbiter registration.

In current kernels this is mostly benign because vfio_pci_set_decode()
only uses pci_dev state, but the original failure path could leave a
callback with a freed vdev cookie.  The stale registration also becomes
unsafe again once the callback follows drvdata to the vfio device.

Add the required VGA unwind callout.

Fixes: 4aeec3984ddc ("vfio/pci: Re-order vfio_pci_probe()")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Alex Williamson <alex.williamson@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20260615191241.688297-3-alex.williamson@nvidia.com
Signed-off-by: Alex Williamson <alex@shazbot.org>

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index f8d1755de2ce..dab82c078580 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -2254,6 +2254,7 @@ int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev)
 		pm_runtime_get_noresume(dev);
 
 	pm_runtime_forbid(dev);
+	vfio_pci_vga_uninit(vdev);
 out_vf:
 	vfio_pci_vf_uninit(vdev);
 	return ret;

[PATCH 5.15.y] vfio/pci: Release the VGA arbiter client on register_device() failure

[Sasha Levin]

From: Alex Williamson <alex.williamson@nvidia.com>

[ Upstream commit daedde7f024ecf88bc8e832ed40cf2c795f0796a ]

The re-order in the Fixes commit below displaced vfio_pci_vga_init() as
the last failure point of what is now vfio_pci_core_register_device()
without introducing an unwind for the VGA arbiter registration.

In current kernels this is mostly benign because vfio_pci_set_decode()
only uses pci_dev state, but the original failure path could leave a
callback with a freed vdev cookie.  The stale registration also becomes
unsafe again once the callback follows drvdata to the vfio device.

Add the required VGA unwind callout.

Fixes: 4aeec3984ddc ("vfio/pci: Re-order vfio_pci_probe()")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Alex Williamson <alex.williamson@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20260615191241.688297-3-alex.williamson@nvidia.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/vfio/pci/vfio_pci_core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index ea4e75be1884f2..2da7067d5c34ab 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1899,6 +1899,7 @@ int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev)
 out_power:
 	if (!disable_idle_d3)
 		vfio_pci_set_power_state(vdev, PCI_D0);
+	vfio_pci_vga_uninit(vdev);
 out_vf:
 	vfio_pci_vf_uninit(vdev);
 out_group_put:
-- 
2.53.0