| Message ID | 20220504014440.3697851-6-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | Introduce flexible array struct memcpy() helpers | expand |
On 5/4/2022 3:44 AM, Kees Cook wrote: > 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. > Reviewed-by: 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; So does mem_to_flex_dup() store event->datalen? Don't have the entire thread so missing bits and pieces, but at least this raises questions for me. Thanks, Arend
On Mon, May 16, 2022 at 02:49:21PM +0200, Arend van Spriel wrote: > On 5/4/2022 3:44 AM, Kees Cook wrote: > > 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. > > > Reviewed-by: Arend van Spriel <aspriel@gmail.com> Thanks! > > [...] > > 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); > > }; > > [...] > > @@ -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; > > So does mem_to_flex_dup() store event->datalen? > > Don't have the entire thread so missing bits and pieces, but at least this > raises questions for me. Yes, that's part of the internal workings here -- the flex array counter is declared and will be set as part of the copy.
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);
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(-)