From 2960a2d33b02345c6d710251206053678f92246b Mon Sep 17 00:00:00 2001 From: "Russell King (Oracle)" Date: Wed, 29 Mar 2023 13:11:17 +0100 Subject: [PATCH] net: mvneta: fix potential double-frees in mvneta_txq_sw_deinit() Reported on the Turris forum, mvneta provokes kernel warnings in the architecture DMA mapping code when mvneta_setup_txqs() fails to allocate memory. This happens because when mvneta_cleanup_txqs() is called in the mvneta_stop() path, we leave pointers in the structure that have been freed. Then on mvneta_open(), we call mvneta_setup_txqs(), which starts allocating memory. On memory allocation failure, mvneta_cleanup_txqs() will walk all the queues freeing any non-NULL pointers - which includes pointers that were previously freed in mvneta_stop(). Fix this by setting these pointers to NULL to prevent double-freeing of the same memory. Fixes: 2adb719d74f6 ("net: mvneta: Implement software TSO") Link: https://forum.turris.cz/t/random-kernel-exceptions-on-hbl-tos-7-0/18865/8 Signed-off-by: Russell King (Oracle) Link: https://lore.kernel.org/r/E1phUe5-00EieL-7q@rmk-PC.armlinux.org.uk Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/marvell/mvneta.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index 0e39d19..2cad76d0 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -3549,6 +3549,8 @@ static void mvneta_txq_sw_deinit(struct mvneta_port *pp, netdev_tx_reset_queue(nq); + txq->buf = NULL; + txq->tso_hdrs = NULL; txq->descs = NULL; txq->last_desc = 0; txq->next_desc_to_proc = 0; -- 2.7.4