Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.14 800/849] dmaengine: ti: k3-udma: Set bchan to NULL if a channel request fail | Date | Mon, 15 Nov 2021 18:04:43 +0100 |
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From: Kishon Vijay Abraham I <kishon@ti.com>
commit 5c6c6d60e4b489308ae4da8424c869f7cc53cd12 upstream.
bcdma_get_*() checks if bchan is already allocated by checking if it has a NON NULL value. For the error cases, bchan will have error value and bcdma_get_*() considers this as already allocated (PASS) since the error values are NON NULL. This results in NULL pointer dereference error while de-referencing bchan.
Reset the value of bchan to NULL if a channel request fails.
CC: stable@vger.kernel.org Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Link: https://lore.kernel.org/r/20211031032411.27235-2-kishon@ti.com Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/dma/ti/k3-udma.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
--- a/drivers/dma/ti/k3-udma.c +++ b/drivers/dma/ti/k3-udma.c @@ -1348,6 +1348,7 @@ static int bcdma_get_bchan(struct udma_c { struct udma_dev *ud = uc->ud; enum udma_tp_level tpl; + int ret; if (uc->bchan) { dev_dbg(ud->dev, "chan%d: already have bchan%d allocated\n", @@ -1365,8 +1366,11 @@ static int bcdma_get_bchan(struct udma_c tpl = ud->bchan_tpl.levels - 1; uc->bchan = __udma_reserve_bchan(ud, tpl, -1); - if (IS_ERR(uc->bchan)) - return PTR_ERR(uc->bchan); + if (IS_ERR(uc->bchan)) { + ret = PTR_ERR(uc->bchan); + uc->bchan = NULL; + return ret; + } uc->tchan = uc->bchan;
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