[PATCH 3/4] net: atlantic: add check for MAX_SKB_FRAGS

From: Grant Grundler
Date: Mon May 09 2022 - 22:29:04 EST


Enforce that the CPU can not get stuck in an infinite loop.

Reported-by: Aashay Shringarpure <aashay@xxxxxxxxxx>
Reported-by: Yi Chou <yich@xxxxxxxxxx>
Reported-by: Shervin Oloumi <enlightened@xxxxxxxxxx>
Signed-off-by: Grant Grundler <grundler@xxxxxxxxxxxx>
---
drivers/net/ethernet/aquantia/atlantic/aq_ring.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
index bc1952131799..8201ce7adb77 100644
--- a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
@@ -363,6 +363,7 @@ int aq_ring_rx_clean(struct aq_ring_s *self,
continue;

if (!buff->is_eop) {
+ unsigned int frag_cnt = 0U;
buff_ = buff;
do {
bool is_rsc_completed = true;
@@ -371,6 +372,8 @@ int aq_ring_rx_clean(struct aq_ring_s *self,
err = -EIO;
goto err_exit;
}
+
+ frag_cnt++;
next_ = buff_->next,
buff_ = &self->buff_ring[next_];
is_rsc_completed =
@@ -378,7 +381,8 @@ int aq_ring_rx_clean(struct aq_ring_s *self,
next_,
self->hw_head);

- if (unlikely(!is_rsc_completed)) {
+ if (unlikely(!is_rsc_completed) ||
+ frag_cnt > MAX_SKB_FRAGS) {
err = 0;
goto err_exit;
}
--
2.36.0.512.ge40c2bad7a-goog