Here is the fix for both 32=>64 and 64=>32 bit translators and a
selftest that reproduced the issue.
Big thanks to YueHaibing for fuzzing and reporting the issue,
I really appreciate it!
Cc: "David S. Miller" <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Steffen Klassert <[email protected]>
Cc: YueHaibing <[email protected]>
Cc: [email protected]
Dmitry Safonov (2):
net/xfrm/compat: Copy xfrm_spdattr_type_t atributes
selftests/net/ipsec: Add test for xfrm_spdattr_type_t
net/xfrm/xfrm_compat.c | 49 ++++++++-
tools/testing/selftests/net/ipsec.c | 165 +++++++++++++++++++++++++++-
2 files changed, 207 insertions(+), 7 deletions(-)
base-commit: e73f0f0ee7541171d89f2e2491130c7771ba58d3
--
2.32.0
The attribute-translator has to take in mind maxtype, that is
xfrm_link::nla_max. When it is set, attributes are not of xfrm_attr_type_t.
Currently, they can be only XFRMA_SPD_MAX (message XFRM_MSG_NEWSPDINFO),
their UABI is the same for 64/32-bit, so just copy them.
Thanks to YueHaibing for reporting this:
In xfrm_user_rcv_msg_compat() if maxtype is not zero and less than
XFRMA_MAX, nlmsg_parse_deprecated() do not initialize attrs array fully.
xfrm_xlate32() will access uninit 'attrs[i]' while iterating all attrs
array.
KASAN: probably user-memory-access in range [0x0000000041b58ab0-0x0000000041b58ab7]
CPU: 0 PID: 15799 Comm: syz-executor.2 Tainted: G W 5.14.0-rc1-syzkaller #0
RIP: 0010:nla_type include/net/netlink.h:1130 [inline]
RIP: 0010:xfrm_xlate32_attr net/xfrm/xfrm_compat.c:410 [inline]
RIP: 0010:xfrm_xlate32 net/xfrm/xfrm_compat.c:532 [inline]
RIP: 0010:xfrm_user_rcv_msg_compat+0x5e5/0x1070 net/xfrm/xfrm_compat.c:577
[...]
Call Trace:
xfrm_user_rcv_msg+0x556/0x8b0 net/xfrm/xfrm_user.c:2774
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
xfrm_netlink_rcv+0x6b/0x90 net/xfrm/xfrm_user.c:2824
netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
sock_sendmsg_nosec net/socket.c:702 [inline]
Fixes: 5106f4a8acff ("xfrm/compat: Add 32=>64-bit messages translator")
Cc: <[email protected]>
Reported-by: YueHaibing <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
net/xfrm/xfrm_compat.c | 49 +++++++++++++++++++++++++++++++++++++-----
1 file changed, 44 insertions(+), 5 deletions(-)
diff --git a/net/xfrm/xfrm_compat.c b/net/xfrm/xfrm_compat.c
index a20aec9d7393..2bf269390163 100644
--- a/net/xfrm/xfrm_compat.c
+++ b/net/xfrm/xfrm_compat.c
@@ -298,8 +298,16 @@ static int xfrm_xlate64(struct sk_buff *dst, const struct nlmsghdr *nlh_src)
len = nlmsg_attrlen(nlh_src, xfrm_msg_min[type]);
nla_for_each_attr(nla, attrs, len, remaining) {
- int err = xfrm_xlate64_attr(dst, nla);
+ int err;
+ switch (type) {
+ case XFRM_MSG_NEWSPDINFO:
+ err = xfrm_nla_cpy(dst, nla, nla_len(nla));
+ break;
+ default:
+ err = xfrm_xlate64_attr(dst, nla);
+ break;
+ }
if (err)
return err;
}
@@ -341,7 +349,8 @@ static int xfrm_alloc_compat(struct sk_buff *skb, const struct nlmsghdr *nlh_src
/* 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])
+ struct nlattr *attrs[XFRMA_MAX + 1],
+ int maxtype)
{
size_t len = nlmsg_len(src);
@@ -358,10 +367,20 @@ static size_t xfrm_user_rcv_calculate_len64(const struct nlmsghdr *src,
case XFRM_MSG_POLEXPIRE:
len += 8;
break;
+ case XFRM_MSG_NEWSPDINFO:
+ /* attirbutes are xfrm_spdattr_type_t, not xfrm_attr_type_t */
+ return len;
default:
break;
}
+ /* Unexpected for anything, but XFRM_MSG_NEWSPDINFO, please
+ * correct both 64=>32-bit and 32=>64-bit translators to copy
+ * new attributes.
+ */
+ if (WARN_ON_ONCE(maxtype))
+ return len;
+
if (attrs[XFRMA_SA])
len += 4;
if (attrs[XFRMA_POLICY])
@@ -440,7 +459,8 @@ static int xfrm_xlate32_attr(void *dst, const struct nlattr *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 size, u8 type, int maxtype,
+ struct netlink_ext_ack *extack)
{
size_t pos;
int i;
@@ -520,6 +540,25 @@ static int xfrm_xlate32(struct nlmsghdr *dst, const struct nlmsghdr *src,
}
pos = dst->nlmsg_len;
+ if (maxtype) {
+ /* attirbutes are xfrm_spdattr_type_t, not xfrm_attr_type_t */
+ WARN_ON_ONCE(src->nlmsg_type != XFRM_MSG_NEWSPDINFO);
+
+ for (i = 1; i <= maxtype; i++) {
+ int err;
+
+ if (!attrs[i])
+ continue;
+
+ /* just copy - no need for translation */
+ err = xfrm_attr_cpy32(dst, &pos, attrs[i], size,
+ nla_len(attrs[i]), nla_len(attrs[i]));
+ if (err)
+ return err;
+ }
+ return 0;
+ }
+
for (i = 1; i < XFRMA_MAX + 1; i++) {
int err;
@@ -564,7 +603,7 @@ static struct nlmsghdr *xfrm_user_rcv_msg_compat(const struct nlmsghdr *h32,
if (err < 0)
return ERR_PTR(err);
- len = xfrm_user_rcv_calculate_len64(h32, attrs);
+ len = xfrm_user_rcv_calculate_len64(h32, attrs, maxtype);
/* The message doesn't need translation */
if (len == nlmsg_len(h32))
return NULL;
@@ -574,7 +613,7 @@ static struct nlmsghdr *xfrm_user_rcv_msg_compat(const struct nlmsghdr *h32,
if (!h64)
return ERR_PTR(-ENOMEM);
- err = xfrm_xlate32(h64, h32, attrs, len, type, extack);
+ err = xfrm_xlate32(h64, h32, attrs, len, type, maxtype, extack);
if (err < 0) {
kvfree(h64);
return ERR_PTR(err);
--
2.32.0
Set hthresh, dump it again and verify thresh.lbits && thresh.rbits.
They are passed as attributes of xfrm_spdattr_type_t, different from
other message attributes that use xfrm_attr_type_t.
Also, test attribute that is bigger than XFRMA_SPD_MAX, currently it
should be silently ignored.
Cc: Shuah Khan <[email protected]>
Cc: [email protected]
Signed-off-by: Dmitry Safonov <[email protected]>
---
tools/testing/selftests/net/ipsec.c | 165 +++++++++++++++++++++++++++-
1 file changed, 163 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/net/ipsec.c b/tools/testing/selftests/net/ipsec.c
index f23438d512c5..3d7dde2c321b 100644
--- a/tools/testing/selftests/net/ipsec.c
+++ b/tools/testing/selftests/net/ipsec.c
@@ -484,13 +484,16 @@ enum desc_type {
MONITOR_ACQUIRE,
EXPIRE_STATE,
EXPIRE_POLICY,
+ SPDINFO_ATTRS,
};
const char *desc_name[] = {
"create tunnel",
"alloc spi",
"monitor acquire",
"expire state",
- "expire policy"
+ "expire policy",
+ "spdinfo attributes",
+ ""
};
struct xfrm_desc {
enum desc_type type;
@@ -1593,6 +1596,155 @@ static int xfrm_expire_policy(int xfrm_sock, uint32_t *seq,
return ret;
}
+static int xfrm_spdinfo_set_thresh(int xfrm_sock, uint32_t *seq,
+ unsigned thresh4_l, unsigned thresh4_r,
+ unsigned thresh6_l, unsigned thresh6_r,
+ bool add_bad_attr)
+
+{
+ struct {
+ struct nlmsghdr nh;
+ union {
+ uint32_t unused;
+ int error;
+ };
+ char attrbuf[MAX_PAYLOAD];
+ } req;
+ struct xfrmu_spdhthresh thresh;
+
+ memset(&req, 0, sizeof(req));
+ req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.unused));
+ req.nh.nlmsg_type = XFRM_MSG_NEWSPDINFO;
+ req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
+ req.nh.nlmsg_seq = (*seq)++;
+
+ thresh.lbits = thresh4_l;
+ thresh.rbits = thresh4_r;
+ if (rtattr_pack(&req.nh, sizeof(req), XFRMA_SPD_IPV4_HTHRESH, &thresh, sizeof(thresh)))
+ return -1;
+
+ thresh.lbits = thresh6_l;
+ thresh.rbits = thresh6_r;
+ if (rtattr_pack(&req.nh, sizeof(req), XFRMA_SPD_IPV6_HTHRESH, &thresh, sizeof(thresh)))
+ return -1;
+
+ if (add_bad_attr) {
+ BUILD_BUG_ON(XFRMA_IF_ID <= XFRMA_SPD_MAX + 1);
+ if (rtattr_pack(&req.nh, sizeof(req), XFRMA_IF_ID, NULL, 0)) {
+ pr_err("adding attribute failed: no space");
+ return -1;
+ }
+ }
+
+ if (send(xfrm_sock, &req, req.nh.nlmsg_len, 0) < 0) {
+ pr_err("send()");
+ return -1;
+ }
+
+ if (recv(xfrm_sock, &req, sizeof(req), 0) < 0) {
+ pr_err("recv()");
+ return -1;
+ } else if (req.nh.nlmsg_type != NLMSG_ERROR) {
+ printk("expected NLMSG_ERROR, got %d", (int)req.nh.nlmsg_type);
+ return -1;
+ }
+
+ if (req.error) {
+ printk("NLMSG_ERROR: %d: %s", req.error, strerror(-req.error));
+ return -1;
+ }
+
+ return 0;
+}
+
+static int xfrm_spdinfo_attrs(int xfrm_sock, uint32_t *seq)
+{
+ struct {
+ struct nlmsghdr nh;
+ union {
+ uint32_t unused;
+ int error;
+ };
+ char attrbuf[MAX_PAYLOAD];
+ } req;
+
+ if (xfrm_spdinfo_set_thresh(xfrm_sock, seq, 32, 31, 120, 16, false)) {
+ pr_err("Can't set SPD HTHRESH");
+ return KSFT_FAIL;
+ }
+
+ memset(&req, 0, sizeof(req));
+
+ req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.unused));
+ req.nh.nlmsg_type = XFRM_MSG_GETSPDINFO;
+ req.nh.nlmsg_flags = NLM_F_REQUEST;
+ req.nh.nlmsg_seq = (*seq)++;
+ if (send(xfrm_sock, &req, req.nh.nlmsg_len, 0) < 0) {
+ pr_err("send()");
+ return KSFT_FAIL;
+ }
+
+ if (recv(xfrm_sock, &req, sizeof(req), 0) < 0) {
+ pr_err("recv()");
+ return KSFT_FAIL;
+ } else if (req.nh.nlmsg_type == XFRM_MSG_NEWSPDINFO) {
+ size_t len = NLMSG_PAYLOAD(&req.nh, sizeof(req.unused));
+ struct rtattr *attr = (void *)req.attrbuf;
+ int got_thresh = 0;
+
+ for (; RTA_OK(attr, len); attr = RTA_NEXT(attr, len)) {
+ if (attr->rta_type == XFRMA_SPD_IPV4_HTHRESH) {
+ struct xfrmu_spdhthresh *t = RTA_DATA(attr);
+
+ got_thresh++;
+ if (t->lbits != 32 || t->rbits != 31) {
+ pr_err("thresh differ: %u, %u",
+ t->lbits, t->rbits);
+ return KSFT_FAIL;
+ }
+ }
+ if (attr->rta_type == XFRMA_SPD_IPV6_HTHRESH) {
+ struct xfrmu_spdhthresh *t = RTA_DATA(attr);
+
+ got_thresh++;
+ if (t->lbits != 120 || t->rbits != 16) {
+ pr_err("thresh differ: %u, %u",
+ t->lbits, t->rbits);
+ return KSFT_FAIL;
+ }
+ }
+ }
+ if (got_thresh != 2) {
+ pr_err("only %d thresh returned by XFRM_MSG_GETSPDINFO", got_thresh);
+ return KSFT_FAIL;
+ }
+ } else if (req.nh.nlmsg_type != NLMSG_ERROR) {
+ printk("expected NLMSG_ERROR, got %d", (int)req.nh.nlmsg_type);
+ return KSFT_FAIL;
+ } else {
+ printk("NLMSG_ERROR: %d: %s", req.error, strerror(-req.error));
+ return -1;
+ }
+
+ /* Restore the default */
+ if (xfrm_spdinfo_set_thresh(xfrm_sock, seq, 32, 32, 128, 128, false)) {
+ pr_err("Can't restore SPD HTHRESH");
+ return KSFT_FAIL;
+ }
+
+ /*
+ * At this moment xfrm uses nlmsg_parse_deprecated(), which
+ * implies NL_VALIDATE_LIBERAL - ignoring attributes with
+ * (type > maxtype). nla_parse_depricated_strict() would enforce
+ * it. Or even stricter nla_parse().
+ * Right now it's not expected to fail, but to be ignored.
+ */
+ if (xfrm_spdinfo_set_thresh(xfrm_sock, seq, 32, 32, 128, 128, true))
+ return KSFT_PASS;
+
+ return KSFT_PASS;
+}
+
static int child_serv(int xfrm_sock, uint32_t *seq,
unsigned int nr, int cmd_fd, void *buf, struct xfrm_desc *desc)
{
@@ -1717,6 +1869,9 @@ static int child_f(unsigned int nr, int test_desc_fd, int cmd_fd, void *buf)
case EXPIRE_POLICY:
ret = xfrm_expire_policy(xfrm_sock, &seq, nr, &desc);
break;
+ case SPDINFO_ATTRS:
+ ret = xfrm_spdinfo_attrs(xfrm_sock, &seq);
+ break;
default:
printk("Unknown desc type %d", desc.type);
exit(KSFT_FAIL);
@@ -1994,8 +2149,10 @@ static int write_proto_plan(int fd, int proto)
* sizeof(xfrm_user_polexpire) = 168 | sizeof(xfrm_user_polexpire) = 176
*
* Check the affected by the UABI difference structures.
+ * Also, check translation for xfrm_set_spdinfo: it has it's own attributes
+ * which needs to be correctly copied, but not translated.
*/
-const unsigned int compat_plan = 4;
+const unsigned int compat_plan = 5;
static int write_compat_struct_tests(int test_desc_fd)
{
struct xfrm_desc desc = {};
@@ -2019,6 +2176,10 @@ static int write_compat_struct_tests(int test_desc_fd)
if (__write_desc(test_desc_fd, &desc))
return -1;
+ desc.type = SPDINFO_ATTRS;
+ if (__write_desc(test_desc_fd, &desc))
+ return -1;
+
return 0;
}
--
2.32.0
On Sat, Jul 17, 2021 at 04:02:20PM +0100, Dmitry Safonov wrote:
> Here is the fix for both 32=>64 and 64=>32 bit translators and a
> selftest that reproduced the issue.
>
> Big thanks to YueHaibing for fuzzing and reporting the issue,
> I really appreciate it!
>
> Cc: "David S. Miller" <[email protected]>
> Cc: Herbert Xu <[email protected]>
> Cc: Jakub Kicinski <[email protected]>
> Cc: Steffen Klassert <[email protected]>
> Cc: YueHaibing <[email protected]>
> Cc: [email protected]
>
> Dmitry Safonov (2):
> net/xfrm/compat: Copy xfrm_spdattr_type_t atributes
> selftests/net/ipsec: Add test for xfrm_spdattr_type_t
>
> net/xfrm/xfrm_compat.c | 49 ++++++++-
> tools/testing/selftests/net/ipsec.c | 165 +++++++++++++++++++++++++++-
> 2 files changed, 207 insertions(+), 7 deletions(-)
Series applied, thanks Dmitry!