From 65bcc5f89704efe5b9d69d4ea2c1002d90c31382 Mon Sep 17 00:00:00 2001 From: Slawomir Stepien Date: Mon, 14 Sep 2026 11:50:07 +0200 Subject: [PATCH] HID: amd_sfh: Validate PCI BAR size before mapping The amd_sfh driver maps PCI BAR 2 using pcim_iomap_regions() and subsequently accesses MMIO registers at offsets up to 0x10958 (e.g., AMD_P2C_MSG3 at 0x1068C). However, the driver never validates that the BAR size is large enough to cover these accesses. If the driver is bound to a device with a smaller BAR 2, this leads to an out-of-bounds memory access and a page fault during the probe function. For example, a page fault can occur when reading from privdata->mmio + AMD_P2C_MSG3 in mp2_select_ops(): BUG: unable to handle page fault for address: ffffc9000390368c PGD 100000067 P4D 100000067 PUD 1012c1067 PMD 105b64067 PTE 0 Oops: Oops: 0000 [#1] SMP KASAN NOPTI RIP: 0010:readl arch/x86/include/asm/io.h:59 [inline] RIP: 0010:mp2_select_ops drivers/hid/amd-sfh-hid/amd_sfh_pcie.c:282 [inline] RIP: 0010:amd_mp2_pci_probe+0x337/0x5f0 drivers/hid/amd-sfh-hid/amd_sfh_pcie.c:487 Call Trace: local_pci_probe drivers/pci/pci-driver.c:332 [inline] pci_call_probe drivers/pci/pci-driver.c:394 [inline] __pci_device_probe drivers/pci/pci-driver.c:455 [inline] pci_device_probe+0x431/0xc90 drivers/pci/pci-driver.c:489 Fix this by verifying that the length of BAR 2 is at least 128KB before attempting to map it. Since the maximum accessed offset is 0x10958, and PCI BAR sizes are powers of 2, any legitimate hardware will have a BAR size of at least 128KB. Fixes: 4f567b9f8141 ("SFH: PCIe driver to add support of AMD sensor fusion hub") Assisted-by: Gemini:gemini-3.7-flash Gemini:gemini-3.1-pro-preview syzbot Reported-by: syzbot+4eadd4dfe9e66522bae8@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4eadd4dfe9e66522bae8 Link: https://syzkaller.appspot.com/ai_job?id=3bc1c45c-548f-4ab5-8243-d2c8ec321d6c Signed-off-by: Slawomir Stepien Acked-by: Basavaraj Natikar Link: https://syzkaller.appspot.com/bug?extid=4eadd4dfe9e66522bae8 Signed-off-by: Jiri Kosina --- drivers/hid/amd-sfh-hid/amd_sfh_common.h | 4 ++++ drivers/hid/amd-sfh-hid/amd_sfh_pcie.c | 10 ++++++++++ 2 files changed, 14 insertions(+) diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_common.h b/drivers/hid/amd-sfh-hid/amd_sfh_common.h index f8c6b7fc34fb..3d29119a3765 100644 --- a/drivers/hid/amd-sfh-hid/amd_sfh_common.h +++ b/drivers/hid/amd-sfh-hid/amd_sfh_common.h @@ -13,11 +13,15 @@ #include #include #include +#include #include "amd_sfh_hid.h" #define PCI_DEVICE_ID_AMD_MP2 0x15E4 #define PCI_DEVICE_ID_AMD_MP2_1_1 0x164A +/* The BAR 2 size must cover the highest register offset (0x10958) */ +#define AMD_SFH_MIN_BAR_SIZE SZ_128K + #define AMD_C2P_MSG(regno) (0x10500 + ((regno) * 4)) #define AMD_P2C_MSG(regno) (0x10680 + ((regno) * 4)) diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c index eda26a094d3f..061a63519d44 100644 --- a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c +++ b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c @@ -497,6 +497,16 @@ static int amd_mp2_pci_probe(struct pci_dev *pdev, const struct pci_device_id *i if (rc) return rc; + if (!(pci_resource_flags(pdev, 2) & IORESOURCE_MEM)) { + dev_err(&pdev->dev, "BAR 2 is not IORESOURCE_MEM\n"); + return -ENODEV; + } + + if (pci_resource_len(pdev, 2) < AMD_SFH_MIN_BAR_SIZE) { + dev_err(&pdev->dev, "BAR 2 is too small\n"); + return -EINVAL; + } + rc = pcim_iomap_regions(pdev, BIT(2), DRIVER_NAME); if (rc) return rc;