From 1b47fd4551061ad6db5adf063d424aded798a7c9 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Sat, 2 Jan 2016 00:27:01 +0000 Subject: [PATCH] PCI: acpiphp_ibm: Fix null dereferences on null ibm_slot ibm_slot_from_id() can return null if the des header signature is not "aPCI" or if the kmalloc() for the return ACPI descriptor fails, causing potential null pointer dereferences on the return null descriptor. Handle the null case with appropriate check and error return. Signed-off-by: Colin Ian King Signed-off-by: Bjorn Helgaas --- drivers/pci/hotplug/acpiphp_ibm.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/pci/hotplug/acpiphp_ibm.c b/drivers/pci/hotplug/acpiphp_ibm.c index 6ca23998ee8f..9d16c9dbd76e 100644 --- a/drivers/pci/hotplug/acpiphp_ibm.c +++ b/drivers/pci/hotplug/acpiphp_ibm.c @@ -154,7 +154,8 @@ static union apci_descriptor *ibm_slot_from_id(int id) ibm_slot_done: if (ret) { ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL); - memcpy(ret, des, sizeof(union apci_descriptor)); + if (ret) + memcpy(ret, des, sizeof(union apci_descriptor)); } kfree(table); return ret; @@ -175,8 +176,13 @@ static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status) acpi_status stat; unsigned long long rc; union apci_descriptor *ibm_slot; + int id = hpslot_to_sun(slot); - ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); + ibm_slot = ibm_slot_from_id(id); + if (!ibm_slot) { + pr_err("APLS null ACPI descriptor for slot %d\n", id); + return -ENODEV; + } pr_debug("%s: set slot %d (%d) attention status to %d\n", __func__, ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, @@ -215,8 +221,13 @@ static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status) static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status) { union apci_descriptor *ibm_slot; + int id = hpslot_to_sun(slot); - ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); + ibm_slot = ibm_slot_from_id(id); + if (!ibm_slot) { + pr_err("APLS null ACPI descriptor for slot %d\n", id); + return -ENODEV; + } if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08) *status = 1;