[PATCH 4.14 041/237] brcmfmac: Fix use after free in brcmf_sdio_readframes()

Greg Kroah-Hartman
2020-02-27T14:40:13Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 216b44000ada87a63891a8214c347e05a4aea8fe ]

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@oracle.com>
Acked-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
index 4c28b04ea6053..d198a8780b966 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
@@ -1932,6 +1932,7 @@ static uint brcmf_sdio_readframes(struct brcmf_sdio *bus, uint maxframes)
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)) {
--
2.20.1