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From:   Maksim Davydov <davydov-max@yandex-team.ru>
To:     rajur@chelsio.com
Cc:     davydov-max@yandex-team.ru, davem@davemloft.net,
        edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
        anish@chelsio.com, hariprasad@chelsio.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH net 1/2] net/ethernet/chelsio: fix cxgb4_getpgtccfg wrong memory access
Date:   Mon, 16 Jan 2023 18:20:59 +0300
Message-Id: <20230116152100.30094-2-davydov-max@yandex-team.ru>
In-Reply-To: <20230116152100.30094-1-davydov-max@yandex-team.ru>
References: <20230116152100.30094-1-davydov-max@yandex-team.ru>
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*pgid can be in range 0 to 0xF (bitmask 0xF) but valid values for PGID
are between 0 and 7. Also the size of pgrate is 8. Thus, we are needed
additional check to make sure that this code doesn't have access to tsa.

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.

Fixes: 76bcb31efc06 ("cxgb4 : Add DCBx support codebase and dcbnl_ops")
Signed-off-by: Maksim Davydov <davydov-max@yandex-team.ru>
---
 drivers/net/ethernet/chelsio/cxgb4/cxgb4_dcb.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_dcb.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_dcb.c
index 7d5204834ee2..3aa65f0f335e 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_dcb.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_dcb.c
@@ -471,7 +471,10 @@ static void cxgb4_getpgtccfg(struct net_device *dev, int tc,
 		return;
 	}
 
-	*bw_per = pcmd.u.dcb.pgrate.pgrate[*pgid];
+	/* Valid values are: 0-7 */
+	if (*pgid <= 7)
+		*bw_per = pcmd.u.dcb.pgrate.pgrate[*pgid];
+
 	*up_tc_map = (1 << tc);
 
 	/* prio_type is link strict */
-- 
2.25.1