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

Commit Message

Kees Cook May 4, 2022, 1:44 a.m. UTC

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 <[e-mail]>
Cc: Franky Lin <[e-mail]>
Cc: Hante Meuleman <[e-mail]>
Cc: Kalle Valo <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: Eric Dumazet <[e-mail]>
Cc: Jakub Kicinski <[e-mail]>
Cc: Paolo Abeni <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Kees Cook <[e-mail]>
---
 .../net/wireless/broadcom/brcm80211/brcmfmac/fweh.c   | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

Patch

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);