[PATCH] net: qlcnic: validate unified ROM directory bounds

[Pengpeng Hou <pengpeng@iscas.ac.cn>]

The unified ROM parser walks directory and data descriptor tables from the
firmware file. The existing checks compute table and data limits with
base + count * size or base + size before comparing with the firmware
size. Those calculations use fields from the firmware image and can wrap
before the comparison.

Add range helpers that validate tables and entries with division and
subtraction instead of overflowing additions. Pass the firmware size into
the directory lookup helper, validate each directory entry before reading
its type field, and validate bootloader, firmware and product-table
entries before their descriptor fields are used.

Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
---
 .../net/ethernet/qlogic/qlcnic/qlcnic_init.c  | 135 +++++++++++-------
 1 file changed, 86 insertions(+), 49 deletions(-)

diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_init.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_init.c
index 9192c5ad5a16..56620aed804b 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_init.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_init.c
@@ -740,21 +740,55 @@ qlcnic_has_mn(struct qlcnic_adapter *adapter)
 	return 0;
 }
 
-static
-struct uni_table_desc *qlcnic_get_table_desc(const u8 *unirom, int section)
+#define QLCNIC_UNI_DIR_TYPE_OFF		8
+#define QLCNIC_UNI_DIR_ENTRY_MIN_SIZE \
+	((QLCNIC_UNI_DIR_TYPE_OFF + 1) * sizeof(__le32))
+#define QLCNIC_UNI_PRODUCT_ENTRY_MIN_SIZE \
+	((QLCNIC_UNI_FIRMWARE_IDX_OFF + 1) * sizeof(__le32))
+
+static bool qlcnic_rom_range_valid(size_t fw_size, u32 offset, u32 len)
+{
+	return offset <= fw_size && len <= fw_size - offset;
+}
+
+static bool qlcnic_rom_table_valid(size_t size, u32 off, u32 n, u32 esz)
+{
+	if (off > size)
+		return false;
+	if (!esz)
+		return n == 0;
+
+	return n <= (size - off) / esz;
+}
+
+static bool qlcnic_rom_entry_valid(size_t size, u32 off, u32 esz, u32 idx)
+{
+	if (!esz || off > size)
+		return false;
+
+	return idx < (size - off) / esz;
+}
+
+static struct uni_table_desc *qlcnic_get_table_desc(const u8 *unirom,
+						    size_t fw_size, int section)
 {
-	u32 i, entries;
 	struct uni_table_desc *directory = (struct uni_table_desc *) &unirom[0];
-	entries = le32_to_cpu(directory->num_entries);
+	u32 entries = le32_to_cpu(directory->num_entries);
+	u32 entry_size = le32_to_cpu(directory->entry_size);
+	u32 findex = le32_to_cpu(directory->findex);
+	u32 i;
 
-	for (i = 0; i < entries; i++) {
+	if (entry_size < QLCNIC_UNI_DIR_ENTRY_MIN_SIZE ||
+	    !qlcnic_rom_table_valid(fw_size, findex, entries, entry_size))
+		return NULL;
 
-		u32 offs = le32_to_cpu(directory->findex) +
-			   i * le32_to_cpu(directory->entry_size);
-		u32 tab_type = le32_to_cpu(*((__le32 *)&unirom[offs] + 8));
+	for (i = 0; i < entries; i++) {
+		size_t offs = findex + (size_t)i * entry_size;
+		u32 tab_type = le32_to_cpu(*((__le32 *)&unirom[offs] +
+						QLCNIC_UNI_DIR_TYPE_OFF));
 
 		if (tab_type == section)
-			return (struct uni_table_desc *) &unirom[offs];
+			return (struct uni_table_desc *)&unirom[offs];
 	}
 
 	return NULL;
@@ -766,19 +800,18 @@ static int
 qlcnic_validate_header(struct qlcnic_adapter *adapter)
 {
 	const u8 *unirom = adapter->fw->data;
-	struct uni_table_desc *directory = (struct uni_table_desc *) &unirom[0];
-	u32 entries, entry_size, tab_size, fw_file_size;
-
-	fw_file_size = adapter->fw->size;
+	struct uni_table_desc *directory = (struct uni_table_desc *)&unirom[0];
+	u32 fw_file_size = adapter->fw->size;
+	u32 entries, entry_size, findex;
 
 	if (fw_file_size < FILEHEADER_SIZE)
 		return -EINVAL;
 
 	entries = le32_to_cpu(directory->num_entries);
 	entry_size = le32_to_cpu(directory->entry_size);
-	tab_size = le32_to_cpu(directory->findex) + (entries * entry_size);
+	findex = le32_to_cpu(directory->findex);
 
-	if (fw_file_size < tab_size)
+	if (!qlcnic_rom_table_valid(fw_file_size, findex, entries, entry_size))
 		return -EINVAL;
 
 	return 0;
@@ -789,31 +822,33 @@ qlcnic_validate_bootld(struct qlcnic_adapter *adapter)
 {
 	struct uni_table_desc *tab_desc;
 	struct uni_data_desc *descr;
-	u32 offs, tab_size, data_size, idx;
 	const u8 *unirom = adapter->fw->data;
+	size_t offs;
+	u32 data_len, data_off, entry_size, findex, idx;
 	__le32 temp;
 
 	temp = *((__le32 *)&unirom[adapter->file_prd_off] +
 		 QLCNIC_UNI_BOOTLD_IDX_OFF);
 	idx = le32_to_cpu(temp);
-	tab_desc = qlcnic_get_table_desc(unirom, QLCNIC_UNI_DIR_SECT_BOOTLD);
+	tab_desc = qlcnic_get_table_desc(unirom, adapter->fw->size,
+					 QLCNIC_UNI_DIR_SECT_BOOTLD);
 
 	if (!tab_desc)
 		return -EINVAL;
 
-	tab_size = le32_to_cpu(tab_desc->findex) +
-		   le32_to_cpu(tab_desc->entry_size) * (idx + 1);
-
-	if (adapter->fw->size < tab_size)
+	entry_size = le32_to_cpu(tab_desc->entry_size);
+	findex = le32_to_cpu(tab_desc->findex);
+	if (entry_size < sizeof(*descr) ||
+	    !qlcnic_rom_entry_valid(adapter->fw->size, findex, entry_size,
+				     idx))
 		return -EINVAL;
 
-	offs = le32_to_cpu(tab_desc->findex) +
-	       le32_to_cpu(tab_desc->entry_size) * idx;
+	offs = findex + (size_t)entry_size * idx;
 	descr = (struct uni_data_desc *)&unirom[offs];
+	data_off = le32_to_cpu(descr->findex);
+	data_len = le32_to_cpu(descr->size);
 
-	data_size = le32_to_cpu(descr->findex) + le32_to_cpu(descr->size);
-
-	if (adapter->fw->size < data_size)
+	if (!qlcnic_rom_range_valid(adapter->fw->size, data_off, data_len))
 		return -EINVAL;
 
 	return 0;
@@ -825,29 +860,31 @@ qlcnic_validate_fw(struct qlcnic_adapter *adapter)
 	struct uni_table_desc *tab_desc;
 	struct uni_data_desc *descr;
 	const u8 *unirom = adapter->fw->data;
-	u32 offs, tab_size, data_size, idx;
+	size_t offs;
+	u32 data_len, data_off, entry_size, findex, idx;
 	__le32 temp;
 
 	temp = *((__le32 *)&unirom[adapter->file_prd_off] +
 		 QLCNIC_UNI_FIRMWARE_IDX_OFF);
 	idx = le32_to_cpu(temp);
-	tab_desc = qlcnic_get_table_desc(unirom, QLCNIC_UNI_DIR_SECT_FW);
+	tab_desc = qlcnic_get_table_desc(unirom, adapter->fw->size,
+					 QLCNIC_UNI_DIR_SECT_FW);
 
 	if (!tab_desc)
 		return -EINVAL;
 
-	tab_size = le32_to_cpu(tab_desc->findex) +
-		   le32_to_cpu(tab_desc->entry_size) * (idx + 1);
-
-	if (adapter->fw->size < tab_size)
+	entry_size = le32_to_cpu(tab_desc->entry_size);
+	findex = le32_to_cpu(tab_desc->findex);
+	if (entry_size < sizeof(*descr) ||
+	    !qlcnic_rom_entry_valid(adapter->fw->size, findex, entry_size,
+				     idx))
 		return -EINVAL;
 
-	offs = le32_to_cpu(tab_desc->findex) +
-	       le32_to_cpu(tab_desc->entry_size) * idx;
+	offs = findex + (size_t)entry_size * idx;
 	descr = (struct uni_data_desc *)&unirom[offs];
-	data_size = le32_to_cpu(descr->findex) + le32_to_cpu(descr->size);
-
-	if (adapter->fw->size < data_size)
+	data_off = le32_to_cpu(descr->findex);
+	data_len = le32_to_cpu(descr->size);
+	if (!qlcnic_rom_range_valid(adapter->fw->size, data_off, data_len))
 		return -EINVAL;
 
 	return 0;
@@ -859,30 +896,30 @@ qlcnic_validate_product_offs(struct qlcnic_adapter *adapter)
 	struct uni_table_desc *ptab_descr;
 	const u8 *unirom = adapter->fw->data;
 	int mn_present = qlcnic_has_mn(adapter);
-	u32 entries, entry_size, tab_size, i;
+	u32 entries, entry_size, findex, i;
+	u32 section = QLCNIC_UNI_DIR_SECT_PRODUCT_TBL;
 	__le32 temp;
 
-	ptab_descr = qlcnic_get_table_desc(unirom,
-				QLCNIC_UNI_DIR_SECT_PRODUCT_TBL);
+	ptab_descr = qlcnic_get_table_desc(unirom, adapter->fw->size, section);
 	if (!ptab_descr)
 		return -EINVAL;
 
 	entries = le32_to_cpu(ptab_descr->num_entries);
 	entry_size = le32_to_cpu(ptab_descr->entry_size);
-	tab_size = le32_to_cpu(ptab_descr->findex) + (entries * entry_size);
-
-	if (adapter->fw->size < tab_size)
+	findex = le32_to_cpu(ptab_descr->findex);
+	if (entry_size < QLCNIC_UNI_PRODUCT_ENTRY_MIN_SIZE ||
+	    !qlcnic_rom_table_valid(adapter->fw->size, findex, entries,
+				     entry_size))
 		return -EINVAL;
 
 nomn:
 	for (i = 0; i < entries; i++) {
-
-		u32 flags, file_chiprev, offs;
+		size_t offs;
+		u32 flags, file_chiprev;
 		u8 chiprev = adapter->ahw->revision_id;
 		u32 flagbit;
 
-		offs = le32_to_cpu(ptab_descr->findex) +
-		       i * le32_to_cpu(ptab_descr->entry_size);
+		offs = findex + (size_t)i * entry_size;
 		temp = *((__le32 *)&unirom[offs] + QLCNIC_UNI_FLAGS_OFF);
 		flags = le32_to_cpu(temp);
 		temp = *((__le32 *)&unirom[offs] + QLCNIC_UNI_CHIP_REV_OFF);
@@ -891,7 +928,7 @@ qlcnic_validate_product_offs(struct qlcnic_adapter *adapter)
 		flagbit = mn_present ? 1 : 2;
 
 		if ((chiprev == file_chiprev) &&
-					((1ULL << flagbit) & flags)) {
+		    ((1ULL << flagbit) & flags)) {
 			adapter->file_prd_off = offs;
 			return 0;
 		}
@@ -945,7 +982,7 @@ struct uni_data_desc *qlcnic_get_data_desc(struct qlcnic_adapter *adapter,
 	temp = *((__le32 *)&unirom[adapter->file_prd_off] + idx_offset);
 	idx = le32_to_cpu(temp);
 
-	tab_desc = qlcnic_get_table_desc(unirom, section);
+	tab_desc = qlcnic_get_table_desc(unirom, adapter->fw->size, section);
 
 	if (tab_desc == NULL)
 		return NULL;
-- 
2.43.0