ANDROID: nfc: fdp: Fix possible buffer overflow in WCS4000 NFC driver
Possible buffer overflow when reading next_read_size bytes into
tmp buffer after next_read_size was extracted from a previous packet.
Bug: 62678828
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
diff --git a/drivers/nfc/fdp/i2c.c b/drivers/nfc/fdp/i2c.c
index 712936f..fbd26ec 100644
--- a/drivers/nfc/fdp/i2c.c
+++ b/drivers/nfc/fdp/i2c.c
@@ -177,6 +177,16 @@
/* Packet that contains a length */
if (tmp[0] == 0 && tmp[1] == 0) {
phy->next_read_size = (tmp[2] << 8) + tmp[3] + 3;
+ /*
+ * Ensure next_read_size does not exceed sizeof(tmp)
+ * for reading that many bytes during next iteration
+ */
+ if (phy->next_read_size > FDP_NCI_I2C_MAX_PAYLOAD) {
+ dev_dbg(&client->dev, "%s: corrupted packet\n",
+ __func__);
+ phy->next_read_size = 5;
+ goto flush;
+ }
} else {
phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD;