[PATCH 3.16 24/99] brcmfmac: Fix use after free in brcmf_sdio_readframes()

From: Ben Hutchings
Date: Wed May 20 2020 - 10:28:08 EST


3.16.84-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit 216b44000ada87a63891a8214c347e05a4aea8fe upstream.

The brcmu_pkt_buf_free_skb() function frees "pkt" so it leads to a
static checker warning:

drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c:1974 brcmf_sdio_readframes()
error: dereferencing freed memory 'pkt'

It looks like there was supposed to be a continue after we free "pkt".

Fixes: 4754fceeb9a6 ("brcmfmac: streamline SDIO read frame routine")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Acked-by: Franky Lin <franky.lin@xxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
@@ -1972,6 +1972,7 @@ static uint brcmf_sdio_readframes(struct
BRCMF_SDIO_FT_NORMAL)) {
rd->len = 0;
brcmu_pkt_buf_free_skb(pkt);
+ continue;
}
bus->sdcnt.rx_readahead_cnt++;
if (rd->len != roundup(rd_new.len, 16)) {