[PATCH 5.15 125/132] net: atlantic: add check for MAX_SKB_FRAGS

Greg Kroah-Hartman
2022-05-23T17:43:36Z

From: Grant Grundler <grundler@chromium.org>

[ Upstream commit 6aecbba12b5c90b26dc062af3b9de8c4b3a2f19f ]

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

Reported-by: Aashay Shringarpure <aashay@google.com>
Reported-by: Yi Chou <yich@google.com>
Reported-by: Shervin Oloumi <enlightened@google.com>
Signed-off-by: Grant Grundler <grundler@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 339efdfb1d49..e9c6f1fa0b1a 100644
--- a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
@@ -362,6 +362,7 @@ 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;
@@ -370,6 +371,8 @@ 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 =
@@ -377,7 +380,8 @@ 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;
}
--
2.35.1