[PATCH 05/32] brcmfmac: Use mem_to_flex_dup() with struct brcmf_fweh_queue_item

Kees Cook
2022-05-04T01:52:45Z

As part of the work to perform bounds checking on all memcpy() uses,
replace the open-coded a deserialization of bytes out of memory into a
trailing flexible array by using a flex_array.h helper to perform the
allocation, bounds checking, and copying.

Cc: Arend van Spriel <aspriel@gmail.com>
Cc: Franky Lin <franky.lin@broadcom.com>
Cc: Hante Meuleman <hante.meuleman@broadcom.com>
Cc: Kalle Valo <kvalo@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-wireless@vger.kernel.org
Cc: brcm80211-dev-list.pdl@broadcom.com
Cc: SHA-cyfmac-dev-list@infineon.com
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
.../net/wireless/broadcom/brcm80211/brcmfmac/fweh.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
index bc3f4e4edcdf..bea798ca6466 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
@@ -32,8 +32,8 @@ struct brcmf_fweh_queue_item {
u8 ifidx;
u8 ifaddr[ETH_ALEN];
struct brcmf_event_msg_be emsg;
- u32 datalen;
- u8 data[];
+ DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(u32, datalen);
+ DECLARE_FLEX_ARRAY_ELEMENTS(u8, data);
};

/*
@@ -395,7 +395,7 @@ void brcmf_fweh_process_event(struct brcmf_pub *drvr,
{
enum brcmf_fweh_event_code code;
struct brcmf_fweh_info *fweh = &drvr->fweh;
- struct brcmf_fweh_queue_item *event;
+ struct brcmf_fweh_queue_item *event = NULL;
void *data;
u32 datalen;

@@ -414,8 +414,7 @@ void brcmf_fweh_process_event(struct brcmf_pub *drvr,
datalen + sizeof(*event_packet) > packet_len)
return;

- event = kzalloc(sizeof(*event) + datalen, gfp);
- if (!event)
+ if (mem_to_flex_dup(&event, data, datalen, gfp))
return;

event->code = code;
@@ -423,8 +422,6 @@ void brcmf_fweh_process_event(struct brcmf_pub *drvr,

/* use memcpy to get aligned event message */
memcpy(&event->emsg, &event_packet->msg, sizeof(event->emsg));
- memcpy(event->data, data, datalen);
- event->datalen = datalen;
memcpy(event->ifaddr, event_packet->eth.h_dest, ETH_ALEN);

brcmf_fweh_queue_event(fweh, event);
--
2.32.0