This is a note to let you know that I've just added the patch titled dmaengine: ti: k3-udma: Set r/tchan or rflow to NULL if request fail to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dmaengine-ti-k3-udma-set-r-tchan-or-rflow-to-null-if-request-fail.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From eb91224e47ec33a0a32c9be0ec0fcb3433e555fd Mon Sep 17 00:00:00 2001 From: Kishon Vijay Abraham I <kishon@xxxxxx> Date: Sun, 31 Oct 2021 08:54:11 +0530 Subject: dmaengine: ti: k3-udma: Set r/tchan or rflow to NULL if request fail From: Kishon Vijay Abraham I <kishon@xxxxxx> 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@xxxxxxxxxxxxxxx Acked-by: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx> Link: https://lore.kernel.org/r/20211031032411.27235-3-kishon@xxxxxx Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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) Patches currently in stable-queue which might be from kishon@xxxxxx are queue-5.14/dmaengine-ti-k3-udma-set-bchan-to-null-if-a-channel-request-fail.patch queue-5.14/arm64-dts-ti-k3-j721e-main-fix-max-virtual-functions.patch queue-5.14/dmaengine-ti-k3-udma-set-r-tchan-or-rflow-to-null-if-request-fail.patch queue-5.14/arm64-dts-ti-j7200-main-fix-bus-range-upto-256-bus-n.patch queue-5.14/arm64-dts-ti-j7200-main-fix-vendor-id-device-id-prop.patch queue-5.14/arm64-dts-ti-k3-j721e-main-fix-bus-range-upto-256-bu.patch