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 <[email protected]> --- 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
