Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).
Also, relocate `event->datalen = datalen;` to before calling
`memcpy(event->data, data, datalen);`, so that the __counted_by
annotation has effect, and flex-array member `data` can be properly
bounds-checked at run-time.
While there, use struct_size() helper, instead of the open-coded
version, to calculate the size for the allocation of the whole
flexible structure, including of course, the flexible-array member.
This code was found with the help of Coccinelle, and audited and
fixed manually.
Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
---
drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
index dac7eb77799b..68960ae98987 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
@@ -33,7 +33,7 @@ struct brcmf_fweh_queue_item {
u8 ifaddr[ETH_ALEN];
struct brcmf_event_msg_be emsg;
u32 datalen;
- u8 data[];
+ u8 data[] __counted_by(datalen);
};
/*
@@ -418,17 +418,17 @@ void brcmf_fweh_process_event(struct brcmf_pub *drvr,
datalen + sizeof(*event_packet) > packet_len)
return;
- event = kzalloc(sizeof(*event) + datalen, gfp);
+ event = kzalloc(struct_size(event, data, datalen), gfp);
if (!event)
return;
+ event->datalen = datalen;
event->code = code;
event->ifidx = event_packet->msg.ifidx;
/* 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);
--
2.34.1
