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From:   Inga Stotland <inga.stotland@intel.com>
To:     linux-bluetooth@vger.kernel.org
Cc:     brian.gix@intel.com, Inga Stotland <inga.stotland@intel.com>
Subject: [PATCH BlueZ] mesh: Fix double free of a pointer in mesh-io-generic
Date:   Wed,  7 Aug 2019 13:06:36 -0700
Message-Id: <20190807200636.19614-1-inga.stotland@intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

This fixes a crash in bluetooth-meshd due to freeing the same pointer
twice. The fix is to initialize the address of freed TX buffer to NULL.
---
 mesh/mesh-io-generic.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/mesh/mesh-io-generic.c b/mesh/mesh-io-generic.c
index 576c5df1b..cc91f494e 100644
--- a/mesh/mesh-io-generic.c
+++ b/mesh/mesh-io-generic.c
@@ -654,8 +654,12 @@ static bool tx_cancel(struct mesh_io *io, const uint8_t *data, uint8_t len)
 			tx = l_queue_remove_if(pvt->tx_pkts, find_by_ad_type,
 							L_UINT_TO_PTR(data[0]));
 			l_free(tx);
+
+			if (tx == pvt->tx)
+				pvt->tx = NULL;
+
 		} while (tx);
-	}  else {
+	} else {
 		struct tx_pattern pattern = {
 			.data = data,
 			.len = len
@@ -665,6 +669,10 @@ static bool tx_cancel(struct mesh_io *io, const uint8_t *data, uint8_t len)
 			tx = l_queue_remove_if(pvt->tx_pkts, find_by_pattern,
 								&pattern);
 			l_free(tx);
+
+			if (tx == pvt->tx)
+				pvt->tx = NULL;
+
 		} while (tx);
 	}
 
-- 
2.21.0