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From:   Grant Grundler <grundler@chromium.org>
To:     Igor Russkikh <irusskikh@marvell.com>
Cc:     Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
        netdev <netdev@vger.kernel.org>,
        "David S . Miller" <davem@davemloft.net>,
        LKML <linux-kernel@vger.kernel.org>,
        Aashay Shringarpure <aashay@google.com>,
        Yi Chou <yich@google.com>,
        Shervin Oloumi <enlightened@google.com>,
        Grant Grundler <grundler@chromium.org>
Subject: [PATCH 4/5] net: atlantic: add check for MAX_SKB_FRAGS
Date:   Mon, 18 Apr 2022 16:17:45 -0700
Message-Id: <20220418231746.2464800-5-grundler@chromium.org>
In-Reply-To: <20220418231746.2464800-1-grundler@chromium.org>
References: <20220418231746.2464800-1-grundler@chromium.org>
MIME-Version: 1.0
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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>
---
 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.rc0.470.gd361397f0d-goog