From: Harald Freudenberger freude@linux.ibm.com
commit bef9f0ba300a55d79a69aa172156072182176515 upstream.
The current kernel uses improved crypto selftests. These tests showed that the current implementation of gcm-aes-s390 is not able to deal with chunks of output buffers which are not a multiple of 16 bytes. This patch introduces a rework of the gcm aes s390 scatter walk handling which now is able to handle any input and output scatter list chunk sizes correctly.
Code has been verified by the crypto selftests, the tcrypt kernel module and additional tests ran via the af_alg interface.
Cc: stable@vger.kernel.org Reported-by: Julian Wiedmann jwi@linux.ibm.com Reviewed-by: Patrick Steuer steuer@linux.ibm.com Signed-off-by: Harald Freudenberger freude@linux.ibm.com Signed-off-by: Heiko Carstens heiko.carstens@de.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/s390/crypto/aes_s390.c | 148 +++++++++++++++++++++++++++++++------------- 1 file changed, 107 insertions(+), 41 deletions(-)
--- a/arch/s390/crypto/aes_s390.c +++ b/arch/s390/crypto/aes_s390.c @@ -826,19 +826,45 @@ static int gcm_aes_setauthsize(struct cr return 0; }
-static void gcm_sg_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg, - unsigned int len) +static void gcm_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg, + unsigned int len) { memset(gw, 0, sizeof(*gw)); gw->walk_bytes_remain = len; scatterwalk_start(&gw->walk, sg); }
-static int gcm_sg_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) +static inline unsigned int _gcm_sg_clamp_and_map(struct gcm_sg_walk *gw) +{ + struct scatterlist *nextsg; + + gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain); + while (!gw->walk_bytes) { + nextsg = sg_next(gw->walk.sg); + if (!nextsg) + return 0; + scatterwalk_start(&gw->walk, nextsg); + gw->walk_bytes = scatterwalk_clamp(&gw->walk, + gw->walk_bytes_remain); + } + gw->walk_ptr = scatterwalk_map(&gw->walk); + return gw->walk_bytes; +} + +static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw, + unsigned int nbytes) +{ + gw->walk_bytes_remain -= nbytes; + scatterwalk_unmap(&gw->walk); + scatterwalk_advance(&gw->walk, nbytes); + scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain); + gw->walk_ptr = NULL; +} + +static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) { int n;
- /* minbytesneeded <= AES_BLOCK_SIZE */ if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) { gw->ptr = gw->buf; gw->nbytes = gw->buf_bytes; @@ -851,13 +877,11 @@ static int gcm_sg_walk_go(struct gcm_sg_ goto out; }
- gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain); - if (!gw->walk_bytes) { - scatterwalk_start(&gw->walk, sg_next(gw->walk.sg)); - gw->walk_bytes = scatterwalk_clamp(&gw->walk, - gw->walk_bytes_remain); + if (!_gcm_sg_clamp_and_map(gw)) { + gw->ptr = NULL; + gw->nbytes = 0; + goto out; } - gw->walk_ptr = scatterwalk_map(&gw->walk);
if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) { gw->ptr = gw->walk_ptr; @@ -869,51 +893,90 @@ static int gcm_sg_walk_go(struct gcm_sg_ n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes); memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n); gw->buf_bytes += n; - gw->walk_bytes_remain -= n; - scatterwalk_unmap(&gw->walk); - scatterwalk_advance(&gw->walk, n); - scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain); - + _gcm_sg_unmap_and_advance(gw, n); if (gw->buf_bytes >= minbytesneeded) { gw->ptr = gw->buf; gw->nbytes = gw->buf_bytes; goto out; } - - gw->walk_bytes = scatterwalk_clamp(&gw->walk, - gw->walk_bytes_remain); - if (!gw->walk_bytes) { - scatterwalk_start(&gw->walk, sg_next(gw->walk.sg)); - gw->walk_bytes = scatterwalk_clamp(&gw->walk, - gw->walk_bytes_remain); + if (!_gcm_sg_clamp_and_map(gw)) { + gw->ptr = NULL; + gw->nbytes = 0; + goto out; } - gw->walk_ptr = scatterwalk_map(&gw->walk); }
out: return gw->nbytes; }
-static void gcm_sg_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) +static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) { - int n; + if (gw->walk_bytes_remain == 0) { + gw->ptr = NULL; + gw->nbytes = 0; + goto out; + } + + if (!_gcm_sg_clamp_and_map(gw)) { + gw->ptr = NULL; + gw->nbytes = 0; + goto out; + }
+ if (gw->walk_bytes >= minbytesneeded) { + gw->ptr = gw->walk_ptr; + gw->nbytes = gw->walk_bytes; + goto out; + } + + scatterwalk_unmap(&gw->walk); + gw->walk_ptr = NULL; + + gw->ptr = gw->buf; + gw->nbytes = sizeof(gw->buf); + +out: + return gw->nbytes; +} + +static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) +{ if (gw->ptr == NULL) - return; + return 0;
if (gw->ptr == gw->buf) { - n = gw->buf_bytes - bytesdone; + int n = gw->buf_bytes - bytesdone; if (n > 0) { memmove(gw->buf, gw->buf + bytesdone, n); - gw->buf_bytes -= n; + gw->buf_bytes = n; } else gw->buf_bytes = 0; - } else { - gw->walk_bytes_remain -= bytesdone; - scatterwalk_unmap(&gw->walk); - scatterwalk_advance(&gw->walk, bytesdone); - scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain); - } + } else + _gcm_sg_unmap_and_advance(gw, bytesdone); + + return bytesdone; +} + +static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) +{ + int i, n; + + if (gw->ptr == NULL) + return 0; + + if (gw->ptr == gw->buf) { + for (i = 0; i < bytesdone; i += n) { + if (!_gcm_sg_clamp_and_map(gw)) + return i; + n = min(gw->walk_bytes, bytesdone - i); + memcpy(gw->walk_ptr, gw->buf + i, n); + _gcm_sg_unmap_and_advance(gw, n); + } + } else + _gcm_sg_unmap_and_advance(gw, bytesdone); + + return bytesdone; }
static int gcm_aes_crypt(struct aead_request *req, unsigned int flags) @@ -926,7 +989,7 @@ static int gcm_aes_crypt(struct aead_req unsigned int pclen = req->cryptlen; int ret = 0;
- unsigned int len, in_bytes, out_bytes, + unsigned int n, len, in_bytes, out_bytes, min_bytes, bytes, aad_bytes, pc_bytes; struct gcm_sg_walk gw_in, gw_out; u8 tag[GHASH_DIGEST_SIZE]; @@ -963,14 +1026,14 @@ static int gcm_aes_crypt(struct aead_req *(u32 *)(param.j0 + ivsize) = 1; memcpy(param.k, ctx->key, ctx->key_len);
- gcm_sg_walk_start(&gw_in, req->src, len); - gcm_sg_walk_start(&gw_out, req->dst, len); + gcm_walk_start(&gw_in, req->src, len); + gcm_walk_start(&gw_out, req->dst, len);
do { min_bytes = min_t(unsigned int, aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE); - in_bytes = gcm_sg_walk_go(&gw_in, min_bytes); - out_bytes = gcm_sg_walk_go(&gw_out, min_bytes); + in_bytes = gcm_in_walk_go(&gw_in, min_bytes); + out_bytes = gcm_out_walk_go(&gw_out, min_bytes); bytes = min(in_bytes, out_bytes);
if (aadlen + pclen <= bytes) { @@ -997,8 +1060,11 @@ static int gcm_aes_crypt(struct aead_req gw_in.ptr + aad_bytes, pc_bytes, gw_in.ptr, aad_bytes);
- gcm_sg_walk_done(&gw_in, aad_bytes + pc_bytes); - gcm_sg_walk_done(&gw_out, aad_bytes + pc_bytes); + n = aad_bytes + pc_bytes; + if (gcm_in_walk_done(&gw_in, n) != n) + return -ENOMEM; + if (gcm_out_walk_done(&gw_out, n) != n) + return -ENOMEM; aadlen -= aad_bytes; pclen -= pc_bytes; } while (aadlen + pclen > 0);