Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Ziyang Xuan <william.xuanziyang@huawei.com>
To:     <sgoutham@marvell.com>, <gakula@marvell.com>,
        <sbhatta@marvell.com>, <hkelam@marvell.com>, <davem@davemloft.net>,
        <edumazet@google.com>, <kuba@kernel.org>, <pabeni@redhat.com>,
        <netdev@vger.kernel.org>
CC:     <linux-kernel@vger.kernel.org>
Subject: [PATCH net 2/2] octeontx2-pf: Fix a potential double free in otx2_sq_free_sqbs()
Date:   Fri, 25 Nov 2022 15:45:46 +0800
Message-ID: <047b210eb3b3a2e26703d8b0570a0a017789c169.1669361183.git.william.xuanziyang@huawei.com>
In-Reply-To: <cover.1669361183.git.william.xuanziyang@huawei.com>
References: <cover.1669361183.git.william.xuanziyang@huawei.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 7BIT
Content-Type:   text/plain; charset=US-ASCII
Precedence: bulk

otx2_sq_free_sqbs() will be called twice when goto "err_free_nix_queues"
label in otx2_init_hw_resources(). The first calling is within
otx2_free_sq_res() at "err_free_nix_queues" label, and the second calling
is at later "err_free_sq_ptrs" label.

In otx2_sq_free_sqbs(), If sq->sqb_ptrs[i] is not 0, the memory page it
points to will be freed, and sq->sqb_ptrs[i] do not be assigned 0 after
memory page be freed. If otx2_sq_free_sqbs() is called twice, the memory
page pointed by sq->sqb_ptrs[i] will be freeed twice. To fix the bug,
assign 0 to sq->sqb_ptrs[i] after memory page be freed.

Fixes: caa2da34fd25 ("octeontx2-pf: Initialize and config queues")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
---
 drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
index 9e10e7471b88..5a25fe51d102 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
@@ -1146,6 +1146,7 @@ void otx2_sq_free_sqbs(struct otx2_nic *pfvf)
 					     DMA_FROM_DEVICE,
 					     DMA_ATTR_SKIP_CPU_SYNC);
 			put_page(virt_to_page(phys_to_virt(pa)));
+			sq->sqb_ptrs[sqb] = 0;
 		}
 		sq->sqb_count = 0;
 	}
-- 
2.25.1