tls: rx: device: bound the frag walk

We can't do skb_walk_frags() on the input skbs, because
the input skbs is really just a pointer to the tcp read
queue. We need to bound the "is decrypted" check by the
amount of data in the message.

Note that the walk in tls_device_reencrypt() is after a
CoW so the skb there is safe to walk. Actually in the
current implementation it can't have frags at all, but
whatever, maybe one day it will.

Reported-by: Tariq Toukan <tariqt@nvidia.com>
Fixes: 84c61fe1a7 ("tls: rx: do not use the standard strparser")
Tested-by: Ran Rozenstein <ranro@nvidia.com>
Link: https://lore.kernel.org/r/20220809175544.354343-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski 2022-08-09 10:55:43 -07:00
parent 9ad36309e2
commit 86b259f6f8

View File

@ -984,11 +984,17 @@ int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
int is_decrypted = skb->decrypted;
int is_encrypted = !is_decrypted;
struct sk_buff *skb_iter;
int left;
left = rxm->full_len - skb->len;
/* Check if all the data is decrypted already */
skb_walk_frags(skb, skb_iter) {
skb_iter = skb_shinfo(skb)->frag_list;
while (skb_iter && left > 0) {
is_decrypted &= skb_iter->decrypted;
is_encrypted &= !skb_iter->decrypted;
left -= skb_iter->len;
skb_iter = skb_iter->next;
}
trace_tls_device_decrypted(sk, tcp_sk(sk)->copied_seq - rxm->full_len,