The current linking of receive sgls is invalid.
It only works with a single list, but when multiple rsgls are being chained
the list is built incorrectly. The following example, when run on the existing
implementation causes an Oops.
----- %< ------
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <linux/types.h>
#define SOL_ALG 279
#define SPLICE_F_GIFT (0x08)
struct sockaddr_alg {
__u16 salg_family;
__u8 salg_type[14];
__u32 salg_feat;
__u32 salg_mask;
__u8 salg_name[64];
};
struct af_alg_iv {
__u32 ivlen;
__u8 iv[0];
};
/* Socket options */
#define ALG_SET_KEY 1
#define ALG_SET_IV 2
#define ALG_SET_OP 3
#define ALG_SET_AEAD_ASSOCLEN 4
#define ALG_SET_AEAD_AUTHSIZE 5
/* Operations */
#define ALG_OP_DECRYPT 0
#define ALG_OP_ENCRYPT 1
#define ASSOCLEN 512
#define AUTHLEN 64
#define PKG_SIZE ((4096 * 16) + ASSOCLEN)
#define PKG_SIZE_TO_READ ((512 * 16) + AUTHLEN)
#define PKG_SINGLE_LEN (512)
#define PKG_SINGLE_RCV_LEN (512)
static char buf[PKG_SIZE]__attribute__((__aligned__(4096)));
void dump(char *mem, unsigned int len)
{
unsigned int i;
for (i = 0; i < len ; i++)
{
if (!(i % 0x10))
printf("0x%04x: ", i);
if (i < len)
printf("%02x ", 0xff & *(mem + i));
if (i && !((i + 1) % 0x10))
printf("\n");
}
}
int main(int argc, char **argv)
{
const char key[16] =
"\x06\xa9\x21\x40\x36\xb8\xa1\x5b"
"\x51\x2e\x03\xd5\x34\x12\x00\x06";
char oiv[16] =
"\x3d\xaf\xba\x42\x9d\x9e\xb4\x30"
"\xb4\x22\xda\x80\x2c\x9f\xac\x41";
int opfd;
int tfmfd;
struct sockaddr_alg sa = {
.salg_family = AF_ALG,
.salg_type = "aead",
.salg_name = "authenc(hmac(sha512),cbc(aes))"
};
struct msghdr msg = {};
struct msghdr rcvmsg = {};
struct cmsghdr *cmsg;
char cbuf[CMSG_SPACE(4) + CMSG_SPACE(4) + CMSG_SPACE(20)] = {};
struct aes_iv {
__u32 len;
__u8 iv[16];
} *iv;
struct iovec iov[16];
struct iovec rcviov[16];
char *ptrs[16];
int pipes[2];
int i, ret;
memset(buf, 'A', PKG_SIZE);
pipe(pipes);
tfmfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
bind(tfmfd, (struct sockaddr *)&sa, sizeof(sa));
setsockopt(tfmfd, SOL_ALG, ALG_SET_KEY, key, 16);
setsockopt(tfmfd, SOL_ALG, ALG_SET_AEAD_AUTHSIZE, NULL, AUTHLEN);
opfd = accept(tfmfd, NULL, 0);
msg.msg_control = cbuf;
msg.msg_controllen = sizeof(cbuf);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_ALG;
cmsg->cmsg_type = ALG_SET_OP;
cmsg->cmsg_len = CMSG_LEN(4);
*(__u32 *)CMSG_DATA(cmsg) = ALG_OP_ENCRYPT;
cmsg = CMSG_NXTHDR(&msg, cmsg);
cmsg->cmsg_level = SOL_ALG;
cmsg->cmsg_type = ALG_SET_AEAD_ASSOCLEN;
cmsg->cmsg_len = CMSG_LEN(4);
*(__u32 *)CMSG_DATA(cmsg) = ASSOCLEN;
cmsg = CMSG_NXTHDR(&msg, cmsg);
cmsg->cmsg_level = SOL_ALG;
cmsg->cmsg_type = ALG_SET_IV;
cmsg->cmsg_len = CMSG_LEN(20);
iv = (void *)CMSG_DATA(cmsg);
iv->len = 16;
memcpy(iv->iv, oiv, 16);
for (i = 0; i < 16; i++)
{
ptrs[i] = malloc(PKG_SINGLE_RCV_LEN);
if (!ptrs[i])
return -1;
memset(ptrs[i], 'A', PKG_SINGLE_RCV_LEN);
}
for (i = 0; i < 16; i++)
{
iov[i].iov_base = buf + i * 4096;
iov[i].iov_len = PKG_SINGLE_LEN;
}
iov[0].iov_len += ASSOCLEN;
msg.msg_iovlen = 0;
msg.msg_flags = MSG_MORE;
for (i = 0; i < 16; i++)
{
rcviov[i].iov_base = ptrs[i];
rcviov[i].iov_len = PKG_SINGLE_RCV_LEN;
}
rcvmsg.msg_iovlen = 16;
rcvmsg.msg_iov = rcviov;
ret = sendmsg(opfd, &msg, 0);
vmsplice(pipes[1], iov, 16, SPLICE_F_GIFT);
splice(pipes[0], NULL, opfd, NULL, PKG_SIZE_TO_READ, 0);
ret = recvmsg(opfd, &rcvmsg, 0);
for (i = 0; i < 16; i++)
{
printf("*********** Buff %d ***************\n", i);
dump(ptrs[i], PKG_SINGLE_RCV_LEN);
free(ptrs[i]);
}
close(opfd);
close(tfmfd);
close(pipes[0]);
close(pipes[1]);
}
----- %< ------
This patch fixes it.
Also minor updates to comments.
Signed-off-by: Tadeusz Struk <tadeusz.struk@xxxxxxxxx>
---
crypto/algif_aead.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c
index 53702e9..a55e4e6 100644
--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -34,7 +34,7 @@ struct aead_ctx {
/*
* RSGL_MAX_ENTRIES is an artificial limit where user space at maximum
* can cause the kernel to allocate RSGL_MAX_ENTRIES * ALG_MAX_PAGES
- * bytes
+ * pages
*/
#define RSGL_MAX_ENTRIES ALG_MAX_PAGES
struct af_alg_sgl rsgl[RSGL_MAX_ENTRIES];
@@ -436,11 +436,10 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored,
if (err < 0)
goto unlock;
usedpages += err;
- /* chain the new scatterlist with initial list */
+ /* chain the new scatterlist with previous one */
if (cnt)
- scatterwalk_crypto_chain(ctx->rsgl[0].sg,
- ctx->rsgl[cnt].sg, 1,
- sg_nents(ctx->rsgl[cnt-1].sg));
+ af_alg_link_sg(&ctx->rsgl[cnt-1], &ctx->rsgl[cnt]);
+
/* we do not need more iovecs as we have sufficient memory */
if (outlen <= usedpages)
break;
--
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