orinoco: validate firmware header
Check the Agere firmware headers for validity before attempting to
download it.
Signed-off-by: David Kilroy <kilroyd@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/orinoco/fw.c b/drivers/net/wireless/orinoco/fw.c
index 7d2292d..9f163fe 100644
--- a/drivers/net/wireless/orinoco/fw.c
+++ b/drivers/net/wireless/orinoco/fw.c
@@ -43,6 +43,33 @@
char signature[0]; /* FW signature length headersize-20 */
} __attribute__ ((packed));
+/* Check the range of various header entries. Return a pointer to a
+ * description of the problem, or NULL if everything checks out. */
+static const char *validate_fw(const struct orinoco_fw_header *hdr, size_t len)
+{
+ u16 hdrsize;
+
+ if (len < sizeof(*hdr))
+ return "image too small";
+ if (memcmp(hdr->hdr_vers, "HFW", 3) != 0)
+ return "format not recognised";
+
+ hdrsize = le16_to_cpu(hdr->headersize);
+ if (hdrsize > len)
+ return "bad headersize";
+ if ((hdrsize + le32_to_cpu(hdr->block_offset)) > len)
+ return "bad block offset";
+ if ((hdrsize + le32_to_cpu(hdr->pdr_offset)) > len)
+ return "bad PDR offset";
+ if ((hdrsize + le32_to_cpu(hdr->pri_offset)) > len)
+ return "bad PRI offset";
+ if ((hdrsize + le32_to_cpu(hdr->compat_offset)) > len)
+ return "bad compat offset";
+
+ /* TODO: consider adding a checksum or CRC to the firmware format */
+ return NULL;
+}
+
/* Download either STA or AP firmware into the card. */
static int
orinoco_dl_firmware(struct orinoco_private *priv,
@@ -58,6 +85,7 @@
const unsigned char *first_block;
const unsigned char *end;
const char *firmware;
+ const char *fw_err;
struct net_device *dev = priv->ndev;
int err = 0;
@@ -93,6 +121,15 @@
hdr = (const struct orinoco_fw_header *) fw_entry->data;
+ fw_err = validate_fw(hdr, fw_entry->size);
+ if (fw_err) {
+ printk(KERN_WARNING "%s: Invalid firmware image detected (%s). "
+ "Aborting download\n",
+ dev->name, fw_err);
+ err = -EINVAL;
+ goto abort;
+ }
+
/* Enable aux port to allow programming */
err = hermesi_program_init(hw, le32_to_cpu(hdr->entry_point));
printk(KERN_DEBUG "%s: Program init returned %d\n", dev->name, err);