From: Johan Hovold <johan@kernel.org> stable inclusion from stable-v6.6.122 commit 1a179ac01ff3993ab97e33cc77c316ed7415cda1 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/13527 CVE: CVE-2025-71186 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit dd6e4943889fb354efa3f700e42739da9bddb6ef ] Make sure to drop the reference taken when looking up the DMA mux platform device during route allocation. Note that holding a reference to a device does not prevent its driver data from going away so there is no point in keeping the reference. Fixes: df7e762db5f6 ("dmaengine: Add STM32 DMAMUX driver") Cc: stable@vger.kernel.org # 4.15 Cc: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com> Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Amelie Delaunay <amelie.delaunay@foss.st.com> Link: https://patch.msgid.link/20251117161258.10679-11-johan@kernel.org Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yin Tirui <yintirui@huawei.com> --- drivers/dma/stm32-dmamux.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/dma/stm32-dmamux.c b/drivers/dma/stm32-dmamux.c index 8d77e2a7939a..791179760782 100644 --- a/drivers/dma/stm32-dmamux.c +++ b/drivers/dma/stm32-dmamux.c @@ -90,23 +90,25 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec, struct stm32_dmamux_data *dmamux = platform_get_drvdata(pdev); struct stm32_dmamux *mux; u32 i, min, max; - int ret; + int ret = -EINVAL; unsigned long flags; if (dma_spec->args_count != 3) { dev_err(&pdev->dev, "invalid number of dma mux args\n"); - return ERR_PTR(-EINVAL); + goto err_put_pdev; } if (dma_spec->args[0] > dmamux->dmamux_requests) { dev_err(&pdev->dev, "invalid mux request number: %d\n", dma_spec->args[0]); - return ERR_PTR(-EINVAL); + goto err_put_pdev; } mux = kzalloc(sizeof(*mux), GFP_KERNEL); - if (!mux) - return ERR_PTR(-ENOMEM); + if (!mux) { + ret = -ENOMEM; + goto err_put_pdev; + } spin_lock_irqsave(&dmamux->lock, flags); mux->chan_id = find_first_zero_bit(dmamux->dma_inuse, @@ -133,7 +135,6 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec, dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", i - 1); if (!dma_spec->np) { dev_err(&pdev->dev, "can't get dma master\n"); - ret = -EINVAL; goto error; } @@ -160,6 +161,8 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec, dev_dbg(&pdev->dev, "Mapping DMAMUX(%u) to DMA%u(%u)\n", mux->request, mux->master, mux->chan_id); + put_device(&pdev->dev); + return mux; error: @@ -167,6 +170,9 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec, error_chan_id: kfree(mux); +err_put_pdev: + put_device(&pdev->dev); + return ERR_PTR(ret); } -- 2.43.0