Re: [PATCH] HID: amd_sfh: Validate BAR 2 as memory-mapped I/O in probe
From: Jiri Kosina <jikos@kernel.org>
Date: 2026-09-11 14:22:30
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On Sat, 15 Aug 2026, Preetam Sundar Das wrote:
Syzbot reported a page fault in amd_mp2_pci_probe(). The fuzzer creates
a malicious PCI device where BAR 2 is defined as an I/O port rather
than a memory-mapped I/O (MMIO) region.
The driver previously assumed BAR 2 would always be MMIO and blindly
passed the I/O port address to readl(), causing a fatal page fault
when the CPU attempted to read from restricted memory.
Fix this by explicitly checking the PCI resource flags after waking
the device. If BAR 2 is not an IORESOURCE_MEM region, safely reject
the device with -EINVAL to prevent the panic.
Fixes: 4f567b9f8141 ("SFH: PCIe driver to add support of AMD sensor fusion hub")
Reported-by: syzbot+4eadd4dfe9e66522bae8@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?id=227a9acbe565367eb7a1277b47115df8706d9a12
Signed-off-by: Preetam Sundar Das <redacted>Basavaraj, can I please get your Ack/Reviewed-by on this one? Thanks.
quoted hunk ↗ jump to hunk
--- drivers/hid/amd-sfh-hid/amd_sfh_pcie.c | 3 +++ 1 file changed, 3 insertions(+)diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c index 4b81cebdc335..aef105a81570 100644 --- a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c +++ b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c@@ -451,6 +451,9 @@ 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)) + return -EINVAL; + rc = pcim_iomap_regions(pdev, BIT(2), DRIVER_NAME); if (rc) return rc;-- 2.43.0
-- Jiri Kosina SUSE Labs