linux/net/xfrm/xfrm_compat.c
Dmitry Safonov ef19e11133 xfrm/compat: Cleanup WARN()s that can be user-triggered
Replace WARN_ONCE() that can be triggered from userspace with
pr_warn_once(). Those still give user a hint what's the issue.

I've left WARN()s that are not possible to trigger with current
code-base and that would mean that the code has issues:
- relying on current compat_msg_min[type] <= xfrm_msg_min[type]
- expected 4-byte padding size difference between
  compat_msg_min[type] and xfrm_msg_min[type]
- compat_policy[type].len <= xfrma_policy[type].len
(for every type)

Reported-by: syzbot+834ffd1afc7212eb8147@syzkaller.appspotmail.com
Fixes: 5f3eea6b7e ("xfrm/compat: Attach xfrm dumps to 64=>32 bit translator")
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: netdev@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2021-03-30 07:29:09 +02:00

633 lines
18 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* XFRM compat layer
* Author: Dmitry Safonov <dima@arista.com>
* Based on code and translator idea by: Florian Westphal <fw@strlen.de>
*/
#include <linux/compat.h>
#include <linux/xfrm.h>
#include <net/xfrm.h>
struct compat_xfrm_lifetime_cfg {
compat_u64 soft_byte_limit, hard_byte_limit;
compat_u64 soft_packet_limit, hard_packet_limit;
compat_u64 soft_add_expires_seconds, hard_add_expires_seconds;
compat_u64 soft_use_expires_seconds, hard_use_expires_seconds;
}; /* same size on 32bit, but only 4 byte alignment required */
struct compat_xfrm_lifetime_cur {
compat_u64 bytes, packets, add_time, use_time;
}; /* same size on 32bit, but only 4 byte alignment required */
struct compat_xfrm_userpolicy_info {
struct xfrm_selector sel;
struct compat_xfrm_lifetime_cfg lft;
struct compat_xfrm_lifetime_cur curlft;
__u32 priority, index;
u8 dir, action, flags, share;
/* 4 bytes additional padding on 64bit */
};
struct compat_xfrm_usersa_info {
struct xfrm_selector sel;
struct xfrm_id id;
xfrm_address_t saddr;
struct compat_xfrm_lifetime_cfg lft;
struct compat_xfrm_lifetime_cur curlft;
struct xfrm_stats stats;
__u32 seq, reqid;
u16 family;
u8 mode, replay_window, flags;
/* 4 bytes additional padding on 64bit */
};
struct compat_xfrm_user_acquire {
struct xfrm_id id;
xfrm_address_t saddr;
struct xfrm_selector sel;
struct compat_xfrm_userpolicy_info policy;
/* 4 bytes additional padding on 64bit */
__u32 aalgos, ealgos, calgos, seq;
};
struct compat_xfrm_userspi_info {
struct compat_xfrm_usersa_info info;
/* 4 bytes additional padding on 64bit */
__u32 min, max;
};
struct compat_xfrm_user_expire {
struct compat_xfrm_usersa_info state;
/* 8 bytes additional padding on 64bit */
u8 hard;
};
struct compat_xfrm_user_polexpire {
struct compat_xfrm_userpolicy_info pol;
/* 8 bytes additional padding on 64bit */
u8 hard;
};
#define XMSGSIZE(type) sizeof(struct type)
static const int compat_msg_min[XFRM_NR_MSGTYPES] = {
[XFRM_MSG_NEWSA - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_usersa_info),
[XFRM_MSG_DELSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id),
[XFRM_MSG_GETSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id),
[XFRM_MSG_NEWPOLICY - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userpolicy_info),
[XFRM_MSG_DELPOLICY - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
[XFRM_MSG_GETPOLICY - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
[XFRM_MSG_ALLOCSPI - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userspi_info),
[XFRM_MSG_ACQUIRE - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_acquire),
[XFRM_MSG_EXPIRE - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_expire),
[XFRM_MSG_UPDPOLICY - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userpolicy_info),
[XFRM_MSG_UPDSA - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_usersa_info),
[XFRM_MSG_POLEXPIRE - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_polexpire),
[XFRM_MSG_FLUSHSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_flush),
[XFRM_MSG_FLUSHPOLICY - XFRM_MSG_BASE] = 0,
[XFRM_MSG_NEWAE - XFRM_MSG_BASE] = XMSGSIZE(xfrm_aevent_id),
[XFRM_MSG_GETAE - XFRM_MSG_BASE] = XMSGSIZE(xfrm_aevent_id),
[XFRM_MSG_REPORT - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_report),
[XFRM_MSG_MIGRATE - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
[XFRM_MSG_NEWSADINFO - XFRM_MSG_BASE] = sizeof(u32),
[XFRM_MSG_GETSADINFO - XFRM_MSG_BASE] = sizeof(u32),
[XFRM_MSG_NEWSPDINFO - XFRM_MSG_BASE] = sizeof(u32),
[XFRM_MSG_GETSPDINFO - XFRM_MSG_BASE] = sizeof(u32),
[XFRM_MSG_MAPPING - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_mapping)
};
static const struct nla_policy compat_policy[XFRMA_MAX+1] = {
[XFRMA_SA] = { .len = XMSGSIZE(compat_xfrm_usersa_info)},
[XFRMA_POLICY] = { .len = XMSGSIZE(compat_xfrm_userpolicy_info)},
[XFRMA_LASTUSED] = { .type = NLA_U64},
[XFRMA_ALG_AUTH_TRUNC] = { .len = sizeof(struct xfrm_algo_auth)},
[XFRMA_ALG_AEAD] = { .len = sizeof(struct xfrm_algo_aead) },
[XFRMA_ALG_AUTH] = { .len = sizeof(struct xfrm_algo) },
[XFRMA_ALG_CRYPT] = { .len = sizeof(struct xfrm_algo) },
[XFRMA_ALG_COMP] = { .len = sizeof(struct xfrm_algo) },
[XFRMA_ENCAP] = { .len = sizeof(struct xfrm_encap_tmpl) },
[XFRMA_TMPL] = { .len = sizeof(struct xfrm_user_tmpl) },
[XFRMA_SEC_CTX] = { .len = sizeof(struct xfrm_sec_ctx) },
[XFRMA_LTIME_VAL] = { .len = sizeof(struct xfrm_lifetime_cur) },
[XFRMA_REPLAY_VAL] = { .len = sizeof(struct xfrm_replay_state) },
[XFRMA_REPLAY_THRESH] = { .type = NLA_U32 },
[XFRMA_ETIMER_THRESH] = { .type = NLA_U32 },
[XFRMA_SRCADDR] = { .len = sizeof(xfrm_address_t) },
[XFRMA_COADDR] = { .len = sizeof(xfrm_address_t) },
[XFRMA_POLICY_TYPE] = { .len = sizeof(struct xfrm_userpolicy_type)},
[XFRMA_MIGRATE] = { .len = sizeof(struct xfrm_user_migrate) },
[XFRMA_KMADDRESS] = { .len = sizeof(struct xfrm_user_kmaddress) },
[XFRMA_MARK] = { .len = sizeof(struct xfrm_mark) },
[XFRMA_TFCPAD] = { .type = NLA_U32 },
[XFRMA_REPLAY_ESN_VAL] = { .len = sizeof(struct xfrm_replay_state_esn) },
[XFRMA_SA_EXTRA_FLAGS] = { .type = NLA_U32 },
[XFRMA_PROTO] = { .type = NLA_U8 },
[XFRMA_ADDRESS_FILTER] = { .len = sizeof(struct xfrm_address_filter) },
[XFRMA_OFFLOAD_DEV] = { .len = sizeof(struct xfrm_user_offload) },
[XFRMA_SET_MARK] = { .type = NLA_U32 },
[XFRMA_SET_MARK_MASK] = { .type = NLA_U32 },
[XFRMA_IF_ID] = { .type = NLA_U32 },
};
static struct nlmsghdr *xfrm_nlmsg_put_compat(struct sk_buff *skb,
const struct nlmsghdr *nlh_src, u16 type)
{
int payload = compat_msg_min[type];
int src_len = xfrm_msg_min[type];
struct nlmsghdr *nlh_dst;
/* Compat messages are shorter or equal to native (+padding) */
if (WARN_ON_ONCE(src_len < payload))
return ERR_PTR(-EMSGSIZE);
nlh_dst = nlmsg_put(skb, nlh_src->nlmsg_pid, nlh_src->nlmsg_seq,
nlh_src->nlmsg_type, payload, nlh_src->nlmsg_flags);
if (!nlh_dst)
return ERR_PTR(-EMSGSIZE);
memset(nlmsg_data(nlh_dst), 0, payload);
switch (nlh_src->nlmsg_type) {
/* Compat message has the same layout as native */
case XFRM_MSG_DELSA:
case XFRM_MSG_DELPOLICY:
case XFRM_MSG_FLUSHSA:
case XFRM_MSG_FLUSHPOLICY:
case XFRM_MSG_NEWAE:
case XFRM_MSG_REPORT:
case XFRM_MSG_MIGRATE:
case XFRM_MSG_NEWSADINFO:
case XFRM_MSG_NEWSPDINFO:
case XFRM_MSG_MAPPING:
WARN_ON_ONCE(src_len != payload);
memcpy(nlmsg_data(nlh_dst), nlmsg_data(nlh_src), src_len);
break;
/* 4 byte alignment for trailing u64 on native, but not on compat */
case XFRM_MSG_NEWSA:
case XFRM_MSG_NEWPOLICY:
case XFRM_MSG_UPDSA:
case XFRM_MSG_UPDPOLICY:
WARN_ON_ONCE(src_len != payload + 4);
memcpy(nlmsg_data(nlh_dst), nlmsg_data(nlh_src), payload);
break;
case XFRM_MSG_EXPIRE: {
const struct xfrm_user_expire *src_ue = nlmsg_data(nlh_src);
struct compat_xfrm_user_expire *dst_ue = nlmsg_data(nlh_dst);
/* compat_xfrm_user_expire has 4-byte smaller state */
memcpy(dst_ue, src_ue, sizeof(dst_ue->state));
dst_ue->hard = src_ue->hard;
break;
}
case XFRM_MSG_ACQUIRE: {
const struct xfrm_user_acquire *src_ua = nlmsg_data(nlh_src);
struct compat_xfrm_user_acquire *dst_ua = nlmsg_data(nlh_dst);
memcpy(dst_ua, src_ua, offsetof(struct compat_xfrm_user_acquire, aalgos));
dst_ua->aalgos = src_ua->aalgos;
dst_ua->ealgos = src_ua->ealgos;
dst_ua->calgos = src_ua->calgos;
dst_ua->seq = src_ua->seq;
break;
}
case XFRM_MSG_POLEXPIRE: {
const struct xfrm_user_polexpire *src_upe = nlmsg_data(nlh_src);
struct compat_xfrm_user_polexpire *dst_upe = nlmsg_data(nlh_dst);
/* compat_xfrm_user_polexpire has 4-byte smaller state */
memcpy(dst_upe, src_upe, sizeof(dst_upe->pol));
dst_upe->hard = src_upe->hard;
break;
}
case XFRM_MSG_ALLOCSPI: {
const struct xfrm_userspi_info *src_usi = nlmsg_data(nlh_src);
struct compat_xfrm_userspi_info *dst_usi = nlmsg_data(nlh_dst);
/* compat_xfrm_user_polexpire has 4-byte smaller state */
memcpy(dst_usi, src_usi, sizeof(src_usi->info));
dst_usi->min = src_usi->min;
dst_usi->max = src_usi->max;
break;
}
/* Not being sent by kernel */
case XFRM_MSG_GETSA:
case XFRM_MSG_GETPOLICY:
case XFRM_MSG_GETAE:
case XFRM_MSG_GETSADINFO:
case XFRM_MSG_GETSPDINFO:
default:
pr_warn_once("unsupported nlmsg_type %d\n", nlh_src->nlmsg_type);
return ERR_PTR(-EOPNOTSUPP);
}
return nlh_dst;
}
static int xfrm_nla_cpy(struct sk_buff *dst, const struct nlattr *src, int len)
{
return nla_put(dst, src->nla_type, len, nla_data(src));
}
static int xfrm_xlate64_attr(struct sk_buff *dst, const struct nlattr *src)
{
switch (src->nla_type) {
case XFRMA_PAD:
/* Ignore */
return 0;
case XFRMA_UNSPEC:
case XFRMA_ALG_AUTH:
case XFRMA_ALG_CRYPT:
case XFRMA_ALG_COMP:
case XFRMA_ENCAP:
case XFRMA_TMPL:
return xfrm_nla_cpy(dst, src, nla_len(src));
case XFRMA_SA:
return xfrm_nla_cpy(dst, src, XMSGSIZE(compat_xfrm_usersa_info));
case XFRMA_POLICY:
return xfrm_nla_cpy(dst, src, XMSGSIZE(compat_xfrm_userpolicy_info));
case XFRMA_SEC_CTX:
return xfrm_nla_cpy(dst, src, nla_len(src));
case XFRMA_LTIME_VAL:
return nla_put_64bit(dst, src->nla_type, nla_len(src),
nla_data(src), XFRMA_PAD);
case XFRMA_REPLAY_VAL:
case XFRMA_REPLAY_THRESH:
case XFRMA_ETIMER_THRESH:
case XFRMA_SRCADDR:
case XFRMA_COADDR:
return xfrm_nla_cpy(dst, src, nla_len(src));
case XFRMA_LASTUSED:
return nla_put_64bit(dst, src->nla_type, nla_len(src),
nla_data(src), XFRMA_PAD);
case XFRMA_POLICY_TYPE:
case XFRMA_MIGRATE:
case XFRMA_ALG_AEAD:
case XFRMA_KMADDRESS:
case XFRMA_ALG_AUTH_TRUNC:
case XFRMA_MARK:
case XFRMA_TFCPAD:
case XFRMA_REPLAY_ESN_VAL:
case XFRMA_SA_EXTRA_FLAGS:
case XFRMA_PROTO:
case XFRMA_ADDRESS_FILTER:
case XFRMA_OFFLOAD_DEV:
case XFRMA_SET_MARK:
case XFRMA_SET_MARK_MASK:
case XFRMA_IF_ID:
return xfrm_nla_cpy(dst, src, nla_len(src));
default:
BUILD_BUG_ON(XFRMA_MAX != XFRMA_IF_ID);
pr_warn_once("unsupported nla_type %d\n", src->nla_type);
return -EOPNOTSUPP;
}
}
/* Take kernel-built (64bit layout) and create 32bit layout for userspace */
static int xfrm_xlate64(struct sk_buff *dst, const struct nlmsghdr *nlh_src)
{
u16 type = nlh_src->nlmsg_type - XFRM_MSG_BASE;
const struct nlattr *nla, *attrs;
struct nlmsghdr *nlh_dst;
int len, remaining;
nlh_dst = xfrm_nlmsg_put_compat(dst, nlh_src, type);
if (IS_ERR(nlh_dst))
return PTR_ERR(nlh_dst);
attrs = nlmsg_attrdata(nlh_src, xfrm_msg_min[type]);
len = nlmsg_attrlen(nlh_src, xfrm_msg_min[type]);
nla_for_each_attr(nla, attrs, len, remaining) {
int err = xfrm_xlate64_attr(dst, nla);
if (err)
return err;
}
nlmsg_end(dst, nlh_dst);
return 0;
}
static int xfrm_alloc_compat(struct sk_buff *skb, const struct nlmsghdr *nlh_src)
{
u16 type = nlh_src->nlmsg_type - XFRM_MSG_BASE;
struct sk_buff *new = NULL;
int err;
if (type >= ARRAY_SIZE(xfrm_msg_min)) {
pr_warn_once("unsupported nlmsg_type %d\n", nlh_src->nlmsg_type);
return -EOPNOTSUPP;
}
if (skb_shinfo(skb)->frag_list == NULL) {
new = alloc_skb(skb->len + skb_tailroom(skb), GFP_ATOMIC);
if (!new)
return -ENOMEM;
skb_shinfo(skb)->frag_list = new;
}
err = xfrm_xlate64(skb_shinfo(skb)->frag_list, nlh_src);
if (err) {
if (new) {
kfree_skb(new);
skb_shinfo(skb)->frag_list = NULL;
}
return err;
}
return 0;
}
/* Calculates len of translated 64-bit message. */
static size_t xfrm_user_rcv_calculate_len64(const struct nlmsghdr *src,
struct nlattr *attrs[XFRMA_MAX+1])
{
size_t len = nlmsg_len(src);
switch (src->nlmsg_type) {
case XFRM_MSG_NEWSA:
case XFRM_MSG_NEWPOLICY:
case XFRM_MSG_ALLOCSPI:
case XFRM_MSG_ACQUIRE:
case XFRM_MSG_UPDPOLICY:
case XFRM_MSG_UPDSA:
len += 4;
break;
case XFRM_MSG_EXPIRE:
case XFRM_MSG_POLEXPIRE:
len += 8;
break;
default:
break;
}
if (attrs[XFRMA_SA])
len += 4;
if (attrs[XFRMA_POLICY])
len += 4;
/* XXX: some attrs may need to be realigned
* if !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
*/
return len;
}
static int xfrm_attr_cpy32(void *dst, size_t *pos, const struct nlattr *src,
size_t size, int copy_len, int payload)
{
struct nlmsghdr *nlmsg = dst;
struct nlattr *nla;
/* xfrm_user_rcv_msg_compat() relies on fact that 32-bit messages
* have the same len or shorted than 64-bit ones.
* 32-bit translation that is bigger than 64-bit original is unexpected.
*/
if (WARN_ON_ONCE(copy_len > payload))
copy_len = payload;
if (size - *pos < nla_attr_size(payload))
return -ENOBUFS;
nla = dst + *pos;
memcpy(nla, src, nla_attr_size(copy_len));
nla->nla_len = nla_attr_size(payload);
*pos += nla_attr_size(copy_len);
nlmsg->nlmsg_len += nla->nla_len;
memset(dst + *pos, 0, payload - copy_len);
*pos += payload - copy_len;
return 0;
}
static int xfrm_xlate32_attr(void *dst, const struct nlattr *nla,
size_t *pos, size_t size,
struct netlink_ext_ack *extack)
{
int type = nla_type(nla);
u16 pol_len32, pol_len64;
int err;
if (type > XFRMA_MAX) {
BUILD_BUG_ON(XFRMA_MAX != XFRMA_IF_ID);
NL_SET_ERR_MSG(extack, "Bad attribute");
return -EOPNOTSUPP;
}
if (nla_len(nla) < compat_policy[type].len) {
NL_SET_ERR_MSG(extack, "Attribute bad length");
return -EOPNOTSUPP;
}
pol_len32 = compat_policy[type].len;
pol_len64 = xfrma_policy[type].len;
/* XFRMA_SA and XFRMA_POLICY - need to know how-to translate */
if (pol_len32 != pol_len64) {
if (nla_len(nla) != compat_policy[type].len) {
NL_SET_ERR_MSG(extack, "Attribute bad length");
return -EOPNOTSUPP;
}
err = xfrm_attr_cpy32(dst, pos, nla, size, pol_len32, pol_len64);
if (err)
return err;
}
return xfrm_attr_cpy32(dst, pos, nla, size, nla_len(nla), nla_len(nla));
}
static int xfrm_xlate32(struct nlmsghdr *dst, const struct nlmsghdr *src,
struct nlattr *attrs[XFRMA_MAX+1],
size_t size, u8 type, struct netlink_ext_ack *extack)
{
size_t pos;
int i;
memcpy(dst, src, NLMSG_HDRLEN);
dst->nlmsg_len = NLMSG_HDRLEN + xfrm_msg_min[type];
memset(nlmsg_data(dst), 0, xfrm_msg_min[type]);
switch (src->nlmsg_type) {
/* Compat message has the same layout as native */
case XFRM_MSG_DELSA:
case XFRM_MSG_GETSA:
case XFRM_MSG_DELPOLICY:
case XFRM_MSG_GETPOLICY:
case XFRM_MSG_FLUSHSA:
case XFRM_MSG_FLUSHPOLICY:
case XFRM_MSG_NEWAE:
case XFRM_MSG_GETAE:
case XFRM_MSG_REPORT:
case XFRM_MSG_MIGRATE:
case XFRM_MSG_NEWSADINFO:
case XFRM_MSG_GETSADINFO:
case XFRM_MSG_NEWSPDINFO:
case XFRM_MSG_GETSPDINFO:
case XFRM_MSG_MAPPING:
memcpy(nlmsg_data(dst), nlmsg_data(src), compat_msg_min[type]);
break;
/* 4 byte alignment for trailing u64 on native, but not on compat */
case XFRM_MSG_NEWSA:
case XFRM_MSG_NEWPOLICY:
case XFRM_MSG_UPDSA:
case XFRM_MSG_UPDPOLICY:
memcpy(nlmsg_data(dst), nlmsg_data(src), compat_msg_min[type]);
break;
case XFRM_MSG_EXPIRE: {
const struct compat_xfrm_user_expire *src_ue = nlmsg_data(src);
struct xfrm_user_expire *dst_ue = nlmsg_data(dst);
/* compat_xfrm_user_expire has 4-byte smaller state */
memcpy(dst_ue, src_ue, sizeof(src_ue->state));
dst_ue->hard = src_ue->hard;
break;
}
case XFRM_MSG_ACQUIRE: {
const struct compat_xfrm_user_acquire *src_ua = nlmsg_data(src);
struct xfrm_user_acquire *dst_ua = nlmsg_data(dst);
memcpy(dst_ua, src_ua, offsetof(struct compat_xfrm_user_acquire, aalgos));
dst_ua->aalgos = src_ua->aalgos;
dst_ua->ealgos = src_ua->ealgos;
dst_ua->calgos = src_ua->calgos;
dst_ua->seq = src_ua->seq;
break;
}
case XFRM_MSG_POLEXPIRE: {
const struct compat_xfrm_user_polexpire *src_upe = nlmsg_data(src);
struct xfrm_user_polexpire *dst_upe = nlmsg_data(dst);
/* compat_xfrm_user_polexpire has 4-byte smaller state */
memcpy(dst_upe, src_upe, sizeof(src_upe->pol));
dst_upe->hard = src_upe->hard;
break;
}
case XFRM_MSG_ALLOCSPI: {
const struct compat_xfrm_userspi_info *src_usi = nlmsg_data(src);
struct xfrm_userspi_info *dst_usi = nlmsg_data(dst);
/* compat_xfrm_user_polexpire has 4-byte smaller state */
memcpy(dst_usi, src_usi, sizeof(src_usi->info));
dst_usi->min = src_usi->min;
dst_usi->max = src_usi->max;
break;
}
default:
NL_SET_ERR_MSG(extack, "Unsupported message type");
return -EOPNOTSUPP;
}
pos = dst->nlmsg_len;
for (i = 1; i < XFRMA_MAX + 1; i++) {
int err;
if (i == XFRMA_PAD)
continue;
if (!attrs[i])
continue;
err = xfrm_xlate32_attr(dst, attrs[i], &pos, size, extack);
if (err)
return err;
}
return 0;
}
static struct nlmsghdr *xfrm_user_rcv_msg_compat(const struct nlmsghdr *h32,
int maxtype, const struct nla_policy *policy,
struct netlink_ext_ack *extack)
{
/* netlink_rcv_skb() checks if a message has full (struct nlmsghdr) */
u16 type = h32->nlmsg_type - XFRM_MSG_BASE;
struct nlattr *attrs[XFRMA_MAX+1];
struct nlmsghdr *h64;
size_t len;
int err;
BUILD_BUG_ON(ARRAY_SIZE(xfrm_msg_min) != ARRAY_SIZE(compat_msg_min));
if (type >= ARRAY_SIZE(xfrm_msg_min))
return ERR_PTR(-EINVAL);
/* Don't call parse: the message might have only nlmsg header */
if ((h32->nlmsg_type == XFRM_MSG_GETSA ||
h32->nlmsg_type == XFRM_MSG_GETPOLICY) &&
(h32->nlmsg_flags & NLM_F_DUMP))
return NULL;
err = nlmsg_parse_deprecated(h32, compat_msg_min[type], attrs,
maxtype ? : XFRMA_MAX, policy ? : compat_policy, extack);
if (err < 0)
return ERR_PTR(err);
len = xfrm_user_rcv_calculate_len64(h32, attrs);
/* The message doesn't need translation */
if (len == nlmsg_len(h32))
return NULL;
len += NLMSG_HDRLEN;
h64 = kvmalloc(len, GFP_KERNEL);
if (!h64)
return ERR_PTR(-ENOMEM);
err = xfrm_xlate32(h64, h32, attrs, len, type, extack);
if (err < 0) {
kvfree(h64);
return ERR_PTR(err);
}
return h64;
}
static int xfrm_user_policy_compat(u8 **pdata32, int optlen)
{
struct compat_xfrm_userpolicy_info *p = (void *)*pdata32;
u8 *src_templates, *dst_templates;
u8 *data64;
if (optlen < sizeof(*p))
return -EINVAL;
data64 = kmalloc_track_caller(optlen + 4, GFP_USER | __GFP_NOWARN);
if (!data64)
return -ENOMEM;
memcpy(data64, *pdata32, sizeof(*p));
memset(data64 + sizeof(*p), 0, 4);
src_templates = *pdata32 + sizeof(*p);
dst_templates = data64 + sizeof(*p) + 4;
memcpy(dst_templates, src_templates, optlen - sizeof(*p));
kfree(*pdata32);
*pdata32 = data64;
return 0;
}
static struct xfrm_translator xfrm_translator = {
.owner = THIS_MODULE,
.alloc_compat = xfrm_alloc_compat,
.rcv_msg_compat = xfrm_user_rcv_msg_compat,
.xlate_user_policy_sockptr = xfrm_user_policy_compat,
};
static int __init xfrm_compat_init(void)
{
return xfrm_register_translator(&xfrm_translator);
}
static void __exit xfrm_compat_exit(void)
{
xfrm_unregister_translator(&xfrm_translator);
}
module_init(xfrm_compat_init);
module_exit(xfrm_compat_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Dmitry Safonov");
MODULE_DESCRIPTION("XFRM 32-bit compatibility layer");