| Message ID | 20230817211531.4193219-1-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Johannes Berg |
| Headers | show |
| Series | wifi: cfg80211: Annotate with __counted_by | expand |
On Thu, Aug 17, 2023 at 2:16 PM Kees Cook <keescook@chromium.org> wrote: > > 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 checking via CONFIG_UBSAN_BOUNDS > (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > As found with Coccinelle[1], add __counted_by for struct cfg80211_acl_data. > Additionally, since the element count member must be set before accessing > the annotated flexible array member, move its initialization earlier. > > [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci > > Cc: Johannes Berg <johannes@sipsolutions.net> > 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: netdev@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Justin Stitt <justinstitt@google.com> > --- > include/net/cfg80211.h | 2 +- > net/wireless/nl80211.c | 3 +-- > 2 files changed, 2 insertions(+), 3 deletions(-) > > diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h > index d6fa7c8767ad..eb73b5af5d04 100644 > --- a/include/net/cfg80211.h > +++ b/include/net/cfg80211.h > @@ -1282,7 +1282,7 @@ struct cfg80211_acl_data { > int n_acl_entries; > > /* Keep it last */ > - struct mac_address mac_addrs[]; > + struct mac_address mac_addrs[] __counted_by(n_acl_entries); > }; > > /** > diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c > index 8bcf8e293308..80633e815311 100644 > --- a/net/wireless/nl80211.c > +++ b/net/wireless/nl80211.c > @@ -4889,13 +4889,12 @@ static struct cfg80211_acl_data *parse_acl_data(struct wiphy *wiphy, > acl = kzalloc(struct_size(acl, mac_addrs, n_entries), GFP_KERNEL); > if (!acl) > return ERR_PTR(-ENOMEM); > + acl->n_acl_entries = n_entries; > > nla_for_each_nested(attr, info->attrs[NL80211_ATTR_MAC_ADDRS], tmp) { > memcpy(acl->mac_addrs[i].addr, nla_data(attr), ETH_ALEN); > i++; > } > - > - acl->n_acl_entries = n_entries; > acl->acl_policy = acl_policy; > > return acl; > -- > 2.34.1 >
On 8/17/23 15:15, Kees Cook wrote: > 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 checking via CONFIG_UBSAN_BOUNDS > (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > As found with Coccinelle[1], add __counted_by for struct cfg80211_acl_data. > Additionally, since the element count member must be set before accessing > the annotated flexible array member, move its initialization earlier. > > [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci > > Cc: Johannes Berg <johannes@sipsolutions.net> > 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: netdev@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Thanks -- Gustavo > --- > include/net/cfg80211.h | 2 +- > net/wireless/nl80211.c | 3 +-- > 2 files changed, 2 insertions(+), 3 deletions(-) > > diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h > index d6fa7c8767ad..eb73b5af5d04 100644 > --- a/include/net/cfg80211.h > +++ b/include/net/cfg80211.h > @@ -1282,7 +1282,7 @@ struct cfg80211_acl_data { > int n_acl_entries; > > /* Keep it last */ > - struct mac_address mac_addrs[]; > + struct mac_address mac_addrs[] __counted_by(n_acl_entries); > }; > > /** > diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c > index 8bcf8e293308..80633e815311 100644 > --- a/net/wireless/nl80211.c > +++ b/net/wireless/nl80211.c > @@ -4889,13 +4889,12 @@ static struct cfg80211_acl_data *parse_acl_data(struct wiphy *wiphy, > acl = kzalloc(struct_size(acl, mac_addrs, n_entries), GFP_KERNEL); > if (!acl) > return ERR_PTR(-ENOMEM); > + acl->n_acl_entries = n_entries; > > nla_for_each_nested(attr, info->attrs[NL80211_ATTR_MAC_ADDRS], tmp) { > memcpy(acl->mac_addrs[i].addr, nla_data(attr), ETH_ALEN); > i++; > } > - > - acl->n_acl_entries = n_entries; > acl->acl_policy = acl_policy; > > return acl;
On 8/17/2023 2:15 PM, Kees Cook wrote: > 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 checking via CONFIG_UBSAN_BOUNDS > (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > As found with Coccinelle[1], add __counted_by for struct cfg80211_acl_data. > Additionally, since the element count member must be set before accessing > the annotated flexible array member, move its initialization earlier. > > [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci > > Cc: Johannes Berg <johannes@sipsolutions.net> > 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: netdev@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Jeff Johnson <quic_jjohnson@quicinc.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index d6fa7c8767ad..eb73b5af5d04 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -1282,7 +1282,7 @@ struct cfg80211_acl_data { int n_acl_entries; /* Keep it last */ - struct mac_address mac_addrs[]; + struct mac_address mac_addrs[] __counted_by(n_acl_entries); }; /** diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 8bcf8e293308..80633e815311 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -4889,13 +4889,12 @@ static struct cfg80211_acl_data *parse_acl_data(struct wiphy *wiphy, acl = kzalloc(struct_size(acl, mac_addrs, n_entries), GFP_KERNEL); if (!acl) return ERR_PTR(-ENOMEM); + acl->n_acl_entries = n_entries; nla_for_each_nested(attr, info->attrs[NL80211_ATTR_MAC_ADDRS], tmp) { memcpy(acl->mac_addrs[i].addr, nla_data(attr), ETH_ALEN); i++; } - - acl->n_acl_entries = n_entries; acl->acl_policy = acl_policy; return acl;
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 checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct cfg80211_acl_data. Additionally, since the element count member must be set before accessing the annotated flexible array member, move its initialization earlier. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Cc: Johannes Berg <johannes@sipsolutions.net> 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: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- include/net/cfg80211.h | 2 +- net/wireless/nl80211.c | 3 +-- 2 files changed, 2 insertions(+), 3 deletions(-)