[PATCH 5.15 872/917] dmaengine: ti: k3-udma: Set r/tchan or rflow to NULL if request fail
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-11-16 00:38:20
Also in:
lkml
From: Kishon Vijay Abraham I <redacted> commit eb91224e47ec33a0a32c9be0ec0fcb3433e555fd upstream. udma_get_*() checks if rchan/tchan/rflow is already allocated by checking if it has a NON NULL value. For the error cases, rchan/tchan/rflow will have error value and udma_get_*() considers this as already allocated (PASS) since the error values are NON NULL. This results in NULL pointer dereference error while de-referencing rchan/tchan/rflow. Reset the value of rchan/tchan/rflow to NULL if a channel request fails. CC: stable@vger.kernel.org Acked-by: Peter Ujfalusi <redacted> Signed-off-by: Kishon Vijay Abraham I <redacted> Link: https://lore.kernel.org/r/20211031032411.27235-3-kishon@ti.com (local) Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/dma/ti/k3-udma.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-)
--- a/drivers/dma/ti/k3-udma.c
+++ b/drivers/dma/ti/k3-udma.c@@ -1380,6 +1380,7 @@ static int bcdma_get_bchan(struct udma_c static int udma_get_tchan(struct udma_chan *uc) { struct udma_dev *ud = uc->ud; + int ret; if (uc->tchan) { dev_dbg(ud->dev, "chan%d: already have tchan%d allocated\n",
@@ -1394,8 +1395,11 @@ static int udma_get_tchan(struct udma_ch */ uc->tchan = __udma_reserve_tchan(ud, uc->config.channel_tpl, uc->config.mapped_channel_id); - if (IS_ERR(uc->tchan)) - return PTR_ERR(uc->tchan); + if (IS_ERR(uc->tchan)) { + ret = PTR_ERR(uc->tchan); + uc->tchan = NULL; + return ret; + } if (ud->tflow_cnt) { int tflow_id;
@@ -1425,6 +1429,7 @@ static int udma_get_tchan(struct udma_ch static int udma_get_rchan(struct udma_chan *uc) { struct udma_dev *ud = uc->ud; + int ret; if (uc->rchan) { dev_dbg(ud->dev, "chan%d: already have rchan%d allocated\n",
@@ -1439,8 +1444,13 @@ static int udma_get_rchan(struct udma_ch */ uc->rchan = __udma_reserve_rchan(ud, uc->config.channel_tpl, uc->config.mapped_channel_id); + if (IS_ERR(uc->rchan)) { + ret = PTR_ERR(uc->rchan); + uc->rchan = NULL; + return ret; + } - return PTR_ERR_OR_ZERO(uc->rchan); + return 0; } static int udma_get_chan_pair(struct udma_chan *uc)
@@ -1494,6 +1504,7 @@ static int udma_get_chan_pair(struct udm static int udma_get_rflow(struct udma_chan *uc, int flow_id) { struct udma_dev *ud = uc->ud; + int ret; if (!uc->rchan) { dev_err(ud->dev, "chan%d: does not have rchan??\n", uc->id);
@@ -1507,8 +1518,13 @@ static int udma_get_rflow(struct udma_ch } uc->rflow = __udma_get_rflow(ud, flow_id); + if (IS_ERR(uc->rflow)) { + ret = PTR_ERR(uc->rflow); + uc->rflow = NULL; + return ret; + } - return PTR_ERR_OR_ZERO(uc->rflow); + return 0; } static void bcdma_put_bchan(struct udma_chan *uc)