On 9/22/23 11:28, 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 tc_pedit.
I think the annotation for struct tc_pedit_sel is missing.
Thanks
--
Gustavo
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: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
Cc: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Cc: Jiri Pirko <jiri@xxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
net/sched/act_pedit.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c
index 1ef8fcfa9997..77c407eff3b0 100644
--- a/net/sched/act_pedit.c
+++ b/net/sched/act_pedit.c
@@ -515,11 +515,11 @@ static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
spin_unlock_bh(&p->tcf_lock);
return -ENOBUFS;
}
+ opt->nkeys = parms->tcfp_nkeys;
memcpy(opt->keys, parms->tcfp_keys,
flex_array_size(opt, keys, parms->tcfp_nkeys));
opt->index = p->tcf_index;
- opt->nkeys = parms->tcfp_nkeys;
opt->flags = parms->tcfp_flags;
opt->action = p->tcf_action;
opt->refcnt = refcount_read(&p->tcf_refcnt) - ref;
