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If the vchan tasklet is still running, descriptor cleanup may race with callback processing and trigger use-after-free. Call vchan_synchronize() in free_chan_resources() and terminate_all() to drain pending tasklet activity before/after descriptor list cleanup. Also fix axi_chan_list_dump_lli() to iterate over desc_head->nr_hw_descs instead of the channel-wide descs_allocated counter. The old bound could exceed the current descriptor array and cause out-of-bounds access in the error-dump path. Signed-off-by: Ilya Polyvyanyy --- drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c index 4d53f077e..4c317ee82 100644 --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c @@ -553,6 +553,7 @@ static void dma_chan_free_chan_resources(struct dma_chan *dchan) axi_chan_disable(chan); axi_chan_irq_disable(chan, DWAXIDMAC_IRQ_ALL); + vchan_synchronize(&chan->vc); vchan_free_chan_resources(&chan->vc); @@ -1049,9 +1050,13 @@ static void axi_chan_dump_lli(struct axi_dma_chan *chan, static void axi_chan_list_dump_lli(struct axi_dma_chan *chan, struct axi_dma_desc *desc_head) { - int count = atomic_read(&chan->descs_allocated); + int count; int i; + if (!desc_head || !desc_head->hw_desc) + return; + + count = desc_head->nr_hw_descs; for (i = 0; i < count; i++) axi_chan_dump_lli(chan, &desc_head->hw_desc[i]); } @@ -1206,6 +1211,7 @@ static int dma_chan_terminate_all(struct dma_chan *dchan) spin_unlock_irqrestore(&chan->vc.lock, flags); vchan_dma_desc_free_list(&chan->vc, &head); + vchan_synchronize(&chan->vc); dev_vdbg(dchan2dev(dchan), "terminated: %s\n", axi_chan_name(chan)); -- 2.54.0