crypto DMACleanup Leak

Vulnerability analysis

In the Cavium CPT crypto accelerator driver, the error cleanup path that unmaps DMA scatter-gather buffers uses the wrong loop index variable, causing it to skip unmapping all successfully-mapped entries (leaking their DMA mappings) and instead repeatedly attempt to unmap the single entry that already failed. This error path is reached when a DMA mapping fails partway through setup, which can be induced under memory pressure. The kernel crypto API is accessible to unprivileged local users via AF_ALG sockets on systems with Cavium Octeon-TX hardware, making the leak triggerable without special privileges. The fix corrects the loop index so each successfully-mapped buffer is properly unmapped during cleanup, preventing both the resource leak and the redundant unmapping of the failed entry.