From e270045b569cc7030abd29857f3a4e7906524ec0 Mon Sep 17 00:00:00 2001 From: Vladimir Kondratiev Date: Sun, 12 May 2013 14:43:33 +0300 Subject: [PATCH] wil6210: Sanity check for reported DMA length If Rx descriptor contains garbage, it is possible to access memory beyond allocated buffer. Check this condition and drop Rx if reported length is unreasonable large Signed-off-by: Vladimir Kondratiev Signed-off-by: John W. Linville --- drivers/net/wireless/ath/wil6210/txrx.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/wil6210/txrx.c b/drivers/net/wireless/ath/wil6210/txrx.c index 6a20f0a..92f1821 100644 --- a/drivers/net/wireless/ath/wil6210/txrx.c +++ b/drivers/net/wireless/ath/wil6210/txrx.c @@ -349,7 +349,13 @@ static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil, d1 = wil_skb_rxdesc(skb); *d1 = *d; + wil_vring_advance_head(vring, 1); dmalen = le16_to_cpu(d1->dma.length); + if (dmalen > sz) { + wil_err(wil, "Rx size too large: %d bytes!\n", dmalen); + kfree(skb); + return NULL; + } skb_trim(skb, dmalen); wil->stats.last_mcs_rx = wil_rxdesc_mcs(d1); @@ -362,8 +368,6 @@ static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil, wil_hex_dump_txrx("Rx ", DUMP_PREFIX_NONE, 32, 4, (const void *)d, sizeof(*d), false); - wil_vring_advance_head(vring, 1); - /* no extra checks if in sniffer mode */ if (ndev->type != ARPHRD_ETHER) return skb; -- 2.7.4