Am Donnerstag, 12. Februar 2015, 17:41:59 schrieb Tom Lendacky: Hi Tom, > 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. There has been a patch around this issue -- see patch 0f477b655a524515ec9a263d70d51f460c05a161 > > 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 -- Ciao Stephan -- 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
