6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Qiuxu Zhuo [ Upstream commit 88efa0de3285be66969b71ec137d9dab1ee19e52 ] A kernel panic was reported with the following kernel log: EDAC igen6: Expected 2 mcs, but only 1 detected. BUG: unable to handle page fault for address: 000000000000d570 ... Hardware name: Notebook V54x_6x_TU/V54x_6x_TU, BIOS Dasharo (coreboot+UEFI) v0.9.0 07/17/2024 RIP: e030:ecclog_handler+0x7e/0xf0 [igen6_edac] ... igen6_probe+0x2a0/0x343 [igen6_edac] ... igen6_init+0xc5/0xff0 [igen6_edac] ... This issue occurred because one memory controller was disabled by the BIOS but the igen6_edac driver still checked all the memory controllers, including this absent one, to identify the source of the error. Accessing the null MMIO for the absent memory controller resulted in the oops above. Fix this issue by reverting the configuration structure to non-const and updating the field 'res_cfg->num_imc' to reflect the number of detected memory controllers. Fixes: 20e190b1c1fd ("EDAC/igen6: Skip absent memory controllers") Reported-by: Marek Marczykowski-Górecki Closes: https://lore.kernel.org/all/aFFN7RlXkaK_loQb@mail-itl/ Suggested-by: Borislav Petkov Signed-off-by: Qiuxu Zhuo Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Tested-by: Marek Marczykowski-Górecki Link: https://lore.kernel.org/r/20250618162307.1523736-1-qiuxu.zhuo@intel.com Signed-off-by: Sasha Levin --- drivers/edac/igen6_edac.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/edac/igen6_edac.c b/drivers/edac/igen6_edac.c index 0cf7f8bde6cac..28a6f9e667218 100644 --- a/drivers/edac/igen6_edac.c +++ b/drivers/edac/igen6_edac.c @@ -558,7 +558,7 @@ static struct res_config mtl_p_cfg = { .err_addr_to_imc_addr = adl_err_addr_to_imc_addr, }; -static const struct pci_device_id igen6_pci_tbl[] = { +static struct pci_device_id igen6_pci_tbl[] = { { PCI_VDEVICE(INTEL, DID_EHL_SKU5), (kernel_ulong_t)&ehl_cfg }, { PCI_VDEVICE(INTEL, DID_EHL_SKU6), (kernel_ulong_t)&ehl_cfg }, { PCI_VDEVICE(INTEL, DID_EHL_SKU7), (kernel_ulong_t)&ehl_cfg }, @@ -1347,9 +1347,11 @@ static int igen6_register_mcis(struct pci_dev *pdev, u64 mchbar) return -ENODEV; } - if (lmc < res_cfg->num_imc) + if (lmc < res_cfg->num_imc) { igen6_printk(KERN_WARNING, "Expected %d mcs, but only %d detected.", res_cfg->num_imc, lmc); + res_cfg->num_imc = lmc; + } return 0; -- 2.53.0