I was doing some testing of the CCP driver using the AF_ALG interface and encountered a BUG_ON statement during scatter-gather DMA mapping. In algif_skcipher.c, before submitting a request to the the Crypto API the input sg list is not updated to mark the last valid sg entry of the input data. So even if there is only a single valid sg entry, sg_nents returns 127 (the initial value used when creating the sg table). In the CCP driver, when making a call to dma_map_sg I supply the number of entries as returned by sg_nents. During this call, the sg elements that are not valid cause a BUG_ON statement to be hit. I've worked around the issue in skcipher_recvmsg by marking the last valid sg entry (sg_mark_end(sgl->sg + sgl->cur - 1)) just before the call to ablkcipher_request_set_crypt and then unmarking the entry after the return from af_alg_wait_for_completion (using sg_unmark_end). Is this an appropriate/valid solution for this issue? If so, I can submit a patch with the fix in algif_skcipher and algif_hash. Thanks, Tom -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
