kernel/linux.git/drivers/pci, branch v6.12.107

PCI: host-generic: Fix NULL pointer dereference on 32-bit CAM systems

2026-08-27T12:32:03+00:00

commit 008cb88edb41f3c7c8e0ed763ff9f26719830984 upstream. On 32-bit systems the config space is too large to ioremap in one go, so pci_ecam_create() maps each bus segment separately and relies on the ->add_bus callback (pci_ecam_add_bus) to populate the per-bus mapping in cfg->winp[]. pci_ecam_map_bus() then uses that mapping as the base for every config access. The generic ECAM ops (pci_generic_ecam_ops) already provide the ->add_bus and ->remove_bus callbacks, but the CAM (legacy) ops in pci-host-generic.c do not. As a result, on a 32-bit host using "pci-host-cam-generic" the per-bus mapping is never set up and the first config read dereferences a NULL base, crashing during bus enumeration: Unable to handle kernel NULL pointer dereference at virtual address 00000800 Oops [#1] CPU: 0 PID: 1 Comm: swapper Not tainted 6.9.7+ #43 Hardware name: Digilent Nexys-Video-A7 RV32 (DT) epc : pci_generic_config_read+0x40/0xb0 ra : pci_generic_config_read+0x2c/0xb0 [] pci_generic_config_read+0x40/0xb0 [] pci_bus_read_config_dword+0x50/0xb0 [] pci_bus_generic_read_dev_vendor_id+0x3c/0x1ec [] pci_scan_single_device+0xa4/0x11c [] pci_scan_slot+0x9c/0x23c [] pci_scan_child_bus_extend+0x58/0x2f4 [] pci_scan_root_bus_bridge+0x64/0xe8 [] pci_host_probe+0x20/0xc8 [] pci_host_common_probe+0x144/0x1e4 Fix this by giving the CAM ops the same ->add_bus/->remove_bus callbacks. Since pci_ecam_add_bus() and pci_ecam_remove_bus() are static to ecam.c, move the CAM ops definition there as pci_generic_cam_ops (mirroring pci_generic_ecam_ops) and export it for pci-host-generic.c to reference. Fixes: 8fe55ef23387 ("PCI: Dynamically map ECAM regions") Signed-off-by: Steffen Persvold [mani: removed timestamp from log] Signed-off-by: Manivannan Sadhasivam Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260709122446.3151899-1-spersvold@gmail.com Signed-off-by: Greg Kroah-Hartman

PCI: Skip Resizable BAR restore on read error

2026-07-24T14:11:49+00:00

[ 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 Signed-off-by: Greg Kroah-Hartman

PCI: Move Resizable BAR code to rebar.c

2026-07-24T14:11:49+00:00

[ Upstream commit 9f71938cd77f32a448f40a288e409eca60e55486 ] For lack of a better place to put it, Resizable BAR code has been placed inside pci.c and setup-res.c that do not use it for anything. Upcoming changes are going to add more Resizable BAR related functions, increasing the code size. As pci.c is huge as is, move the Resizable BAR related code and the BAR resize code from setup-res.c to rebar.c. Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Reviewed-by: Christian König Link: https://patch.msgid.link/20251113180053.27944-2-ilpo.jarvinen@linux.intel.com Stable-dep-of: ee7471fe968d ("PCI: Skip Resizable BAR restore on read error") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

PCI: Fix restoring BARs on BAR resize rollback path

2026-07-24T14:11:48+00:00

[ Upstream commit 337b1b566db087347194e4543ddfdfa5645275cc ] BAR resize operation is implemented in the pci_resize_resource() and pbus_reassign_bridge_resources() functions. pci_resize_resource() can be called either from __resource_resize_store() from sysfs or directly by the driver for the Endpoint Device. The pci_resize_resource() requires that caller has released the device resources that share the bridge window with the BAR to be resized as otherwise the bridge window is pinned in place and cannot be changed. pbus_reassign_bridge_resources() rolls back resources if the resize operation fails, but rollback is performed only for the bridge windows. Because releasing the device resources are done by the caller of the BAR resize interface, these functions performing the BAR resize do not have access to the device resources as they were before the resize. pbus_reassign_bridge_resources() could try __pci_bridge_assign_resources() after rolling back the bridge windows as they were, however, it will not guarantee the resource are assigned due to differences in how FW and the kernel assign the resources (alignment of the start address and tail). To perform rollback robustly, the BAR resize interface has to be altered to also release the device resources that share the bridge window with the BAR to be resized. Also, remove restoring from the entries failed list as saved list should now contain both the bridge windows and device resources so the extra restore is duplicated work. Some drivers (currently only amdgpu) want to prevent releasing some resources. Add exclude_bars param to pci_resize_resource() and make amdgpu pass its register BAR (BAR 2 or 5), which should never be released during resize operation. Normally 64-bit prefetchable resources do not share a bridge window with the 32-bit only register BAR, but there are various fallbacks in the resource assignment logic which may make the resources share the bridge window in rare cases. This change (together with the driver side changes) is to counter the resource releases that had to be done to prevent resource tree corruption in the ("PCI: Release assigned resource before restoring them") change. As such, it likely restores functionality in cases where device resources were released to avoid resource tree conflicts which appeared to be "working" when such conflicts were not correctly detected by the kernel. Reported-by: Simon Richter Link: https://lore.kernel.org/linux-pci/f9a8c975-f5d3-4dd2-988e-4371a1433a60@hogyros.de/ Reported-by: Alex Bennée Link: https://lore.kernel.org/linux-pci/874irqop6b.fsf@draig.linaro.org/ Signed-off-by: Ilpo Järvinen [bhelgaas: squash amdgpu BAR selection from https: //lore.kernel.org/r/20251114103053.13778-1-ilpo.jarvinen@linux.intel.com] Signed-off-by: Bjorn Helgaas Tested-by: Alex Bennée # AVA, AMD GPU Reviewed-by: Christian König Link: https://patch.msgid.link/20251113162628.5946-7-ilpo.jarvinen@linux.intel.com Stable-dep-of: ee7471fe968d ("PCI: Skip Resizable BAR restore on read error") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

PCI: Free saved list without holding pci_bus_sem

2026-07-24T14:11:48+00:00

[ Upstream commit 1d8a0506f69895b7cfd9d5c4546761c508231a8a ] Freeing the saved list does not require holding pci_bus_sem, so the critical section can be made shorter. Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Tested-by: Alex Bennée # AVA, AMD GPU Link: https://patch.msgid.link/20251113162628.5946-6-ilpo.jarvinen@linux.intel.com Stable-dep-of: ee7471fe968d ("PCI: Skip Resizable BAR restore on read error") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

PCI: Prevent resource tree corruption when BAR resize fails

2026-07-24T14:11:48+00:00

[ Upstream commit 91c4c89db41499eea1b29c56655f79c3bae66e93 ] pbus_reassign_bridge_resources() saves bridge windows into the saved list before attempting to adjust resource assignments to perform a BAR resize operation. If resource adjustments cannot be completed fully, rollback is attempted by restoring the resource from the saved list. The rollback, however, does not check whether the resources it restores were assigned by the partial resize attempt. If restore changes addresses of the resource, it can result in corrupting the resource tree. An example of a corrupted resource tree with overlapping addresses: 6200000000000-6203fbfffffff : pciex@620c3c0000000 6200000000000-6203fbff0ffff : PCI Bus 0030:01 6200020000000-62000207fffff : 0030:01:00.0 6200000000000-6203fbff0ffff : PCI Bus 0030:02 A resource that are assigned into the resource tree must remain unchanged. Thus, release such a resource before attempting to restore and claim it back. For simplicity, always do the release and claim back for the resource even in the cases where it is restored to the same address range. Note: this fix may "break" some cases where devices "worked" because the resource tree corruption allowed address space double counting to fit more resource than what can now be assigned without double counting. The upcoming changes to BAR resizing should address those scenarios (to the extent possible). Fixes: 8bb705e3e79d ("PCI: Add pci_resize_resource() for resizing BARs") Reported-by: Simon Richter Link: https://lore.kernel.org/linux-pci/67840a16-99b4-4d8c-9b5c-4721ab0970a2@hogyros.de/ Reported-by: Alex Bennée Link: https://lore.kernel.org/linux-pci/874irqop6b.fsf@draig.linaro.org/ Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Tested-by: Alex Bennée # AVA, AMD GPU Link: https://patch.msgid.link/20251113162628.5946-2-ilpo.jarvinen@linux.intel.com Stable-dep-of: ee7471fe968d ("PCI: Skip Resizable BAR restore on read error") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

PCI: Use pbus_select_window() during BAR resize

2026-07-24T14:11:48+00:00

[ Upstream commit 7dc58aa7f1b32a215fb0b7c6ca30ddf4663dedf4 ] Prior to a BAR resize, __resource_resize_store() loops through the normal resources of the PCI device and releases those that match to the flags of the BAR to be resized. This is necessary to allow resizing also the upstream bridge window as only childless bridge windows can be resized. While the flags check (mostly) works (if corner cases are ignored), the more straightforward way is to check if the resources share the bridge window. Change __resource_resize_store() to do the check using pbus_select_window(). Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20250829131113.36754-16-ilpo.jarvinen@linux.intel.com Stable-dep-of: ee7471fe968d ("PCI: Skip Resizable BAR restore on read error") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

PCI: mediatek: Fix IRQ domain leak when port fails to enable

2026-07-24T14:11:48+00:00

[ Upstream commit f865a57896bd92d7662eb2818d8f48872e2cbbc7 ] When mtk_pcie_enable_port() fails, mtk_pcie_port_free() removes the port from pcie->ports and frees the port structure. However, the IRQ domains set up earlier by mtk_pcie_init_irq_domain() are never freed. Fix this by refactoring mtk_pcie_irq_teardown() into a per-port helper, mtk_pcie_irq_teardown_port(), and calling it from mtk_pcie_setup() when mtk_pcie_enable_port() fails. Since the IRQ teardown must only happen in the probe error path (during resume, child devices may have active MSI mappings and the NOIRQ context prohibits sleeping locks), mtk_pcie_enable_port() is changed to return an error code so callers can distinguish the two paths and act accordingly. This issue was reported by Sashiko while reviewing the EcoNet EN7528 SoC support series. Fixes: b099631df160 ("PCI: mediatek: Add controller support for MT2712 and MT7622") Signed-off-by: Manivannan Sadhasivam Signed-off-by: Manivannan Sadhasivam Cc: stable@vger.kernel.org # 5.10 Cc: Caleb James DeLisle Link: https://patch.msgid.link/20260521174617.17692-1-mani@kernel.org Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

PCI: mediatek: Use generic MACRO for TPVPERL delay

2026-07-24T14:11:48+00:00

[ Upstream commit 2d58bc777728bfc37aa35dce7b90e72296cceb9f ] Use the generic PCI MACRO for TPVPERL delay to wait for clock and power stabilization after PERST# Signal instead of the raw value of 100 ms. Signed-off-by: Christian Marangi Signed-off-by: Manivannan Sadhasivam Reviewed-by: AngeloGioacchino Del Regno Link: https://patch.msgid.link/20251020111121.31779-5-ansuelsmth@gmail.com Stable-dep-of: f865a57896bd ("PCI: mediatek: Fix IRQ domain leak when port fails to enable") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

PCI: mediatek: Convert bool to single quirks entry and bitmap

2026-07-24T14:11:48+00:00

[ Upstream commit 04305367fab7ec9c98eeba315ad09c8b20abce93 ] To clean Mediatek SoC PCIe struct, convert all the bool to a bitmap and use a single quirks to reference all the values. This permits cleaner addition of new quirk without having to define a new bool in the struct. Signed-off-by: Christian Marangi Signed-off-by: Manivannan Sadhasivam Reviewed-by: AngeloGioacchino Del Regno Link: https://patch.msgid.link/20251020111121.31779-4-ansuelsmth@gmail.com Stable-dep-of: f865a57896bd ("PCI: mediatek: Fix IRQ domain leak when port fails to enable") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman