dmaengine: switchtec-dma: fix double-free in switchtec_dma_free_desc()

switchtec_dma_free_desc() frees swdma_chan->hw_sq, hw_cq, and every
desc_ring[] entry without clearing the pointers afterward. If
switchtec_dma_alloc_chan_resources() fails partway through and calls
it during unwind, then a later retry of alloc_chan_resources() fails
in switchtec_dma_alloc_desc() before reallocating one of those
pointers, its own failure path calls switchtec_dma_free_desc() again
and frees the same, already-freed pointers a second time.

NULL out each pointer as it's freed so a subsequent call is a no-op
for anything already released.

Fixes: 30eba9df76ad ("dmaengine: switchtec-dma: Implement hardware initialization and cleanup")
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://patch.msgid.link/20260902062153.31048-2-logang@deltatee.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

0 files changed, 0 insertions, 0 deletions