diff --git a/drivers/net/wwan/iosm/iosm_ipc_mux_codec.c b/drivers/net/wwan/iosm/iosm_ipc_mux_codec.c index bff46f7ca59f..0bbd41263cc2 100644 --- a/drivers/net/wwan/iosm/iosm_ipc_mux_codec.c +++ b/drivers/net/wwan/iosm/iosm_ipc_mux_codec.c @@ -553,19 +553,21 @@ static int mux_dl_process_dg(struct iosm_mux *ipc_mux, struct mux_adbh *adbh, u32 packet_offset, i, rc, dg_len; for (i = 0; i < nr_of_dg; i++, dg++) { - if (le32_to_cpu(dg->datagram_index) - < sizeof(struct mux_adbh)) + u32 dg_index = le32_to_cpu(dg->datagram_index); + + dg_len = le16_to_cpu(dg->datagram_length); + + if (dg_index < sizeof(struct mux_adbh)) goto dg_error; - /* Is the packet inside of the ADB */ - if (le32_to_cpu(dg->datagram_index) >= - le32_to_cpu(adbh->block_length)) { + /* Is the packet inside of the ADB and the received skb ? */ + if (dg_index >= le32_to_cpu(adbh->block_length) || + dg_index >= skb->len || + dg_len > skb->len - dg_index || + dl_head_pad_len >= dg_len) { goto dg_error; } else { - packet_offset = - le32_to_cpu(dg->datagram_index) + - dl_head_pad_len; - dg_len = le16_to_cpu(dg->datagram_length); + packet_offset = dg_index + dl_head_pad_len; /* Pass the packet to the netif layer. */ rc = ipc_mux_net_receive(ipc_mux, if_id, ipc_mux->wwan, packet_offset, @@ -589,12 +591,16 @@ static void mux_dl_adb_decode(struct iosm_mux *ipc_mux, struct mux_adbh *adbh; struct mux_adth *adth; int nr_of_dg, if_id; - u32 adth_index; + u32 adth_index, prev_index = 0; u8 *block; block = skb->data; adbh = (struct mux_adbh *)block; + /* The block header itself must fit in the received skb. */ + if (skb->len < sizeof(struct mux_adbh)) + goto adb_decode_err; + /* Process the aggregated datagram tables. */ adth_index = le32_to_cpu(adbh->first_table_index); @@ -606,6 +612,16 @@ static void mux_dl_adb_decode(struct iosm_mux *ipc_mux, /* Loop through mixed session tables. */ while (adth_index) { + /* The table header must lie within the received skb, and the + * chain must move forward so a modem cannot make the loop + * cycle between two tables. + */ + if (adth_index <= prev_index || + adth_index < sizeof(struct mux_adbh) || + adth_index > skb->len - sizeof(struct mux_adth)) + goto adb_decode_err; + prev_index = adth_index; + /* Get the reference to the table header. */ adth = (struct mux_adth *)(block + adth_index); @@ -629,6 +645,10 @@ static void mux_dl_adb_decode(struct iosm_mux *ipc_mux, if (le16_to_cpu(adth->table_length) < sizeof(struct mux_adth)) goto adb_decode_err; + /* The whole datagram table must fit in the received skb. */ + if (le16_to_cpu(adth->table_length) > skb->len - adth_index) + goto adb_decode_err; + /* Calculate the number of datagrams. */ nr_of_dg = (le16_to_cpu(adth->table_length) - sizeof(struct mux_adth)) /