jimzah/freebsd-src
1
0
Fork 0
mirror of https://github.com/freebsd/freebsd-src.git synced 2024-11-27 13:32:45 +00:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity

netlink: make netlink work correctly on CHERI.

Browse Source 
Current Netlink message writer code relies on executing callbacks
 with arbitrary data (pointer or integer) to flush the completed
 messages.
This arbitrary data is stored as a union of { void *, uint64_t }.
At some stage, the message flushing code copied this data, using
 direct uint64_t assignment instead of copying the union. It lead
 to failure on CHERI, as sizeof(pointer) == 16 there.

Fix the code by making union non-anonymous and copying it entirely.

Reviewed by:	br, jhb, jrtc27
Differential Revision: https://reviews.freebsd.org/D39557
MFC after:	2 weeks
This commit is contained in:
Alexander V. Chernikov 2023-04-13 11:53:49 +00:00
parent 3e5d0784b9
commit 9f324d8ac2
2 changed files with 27 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
sys/netlink/netlink_message_writer.c
View File

@ -116,7 +116,7 @@ nlmsg_get_ns_buf(struct nl_writer *nw, int size, bool waitok)
static bool
nlmsg_write_socket_buf(struct nl_writer *nw, void *buf, int datalen, int cnt)
{
NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw);
NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg.ptr);
if (__predict_false(datalen == 0)) {
free(buf, M_NETLINK);
return (true);
@ -132,13 +132,14 @@ nlmsg_write_socket_buf(struct nl_writer *nw, void *buf, int datalen, int cnt)
free(buf, M_NETLINK);
int io_flags = (nw->ignore_limit) ? NL_IOF_IGNORE_LIMIT : 0;
return (nl_send_one(m, (struct nlpcb *)(nw->arg_ptr), cnt, io_flags));
return (nl_send_one(m, (struct nlpcb *)(nw->arg.ptr), cnt, io_flags));
}
static bool
nlmsg_write_group_buf(struct nl_writer *nw, void *buf, int datalen, int cnt)
{
NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg_ptr);
NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d proto: %d id: %d", buf, datalen,
nw->arg.group.proto, nw->arg.group.id);
if (__predict_false(datalen == 0)) {
free(buf, M_NETLINK);
return (true);
@ -155,15 +156,15 @@ nlmsg_write_group_buf(struct nl_writer *nw, void *buf, int datalen, int cnt)
if (!success)
return (false);
nl_send_group(m, cnt, nw->arg_uint >> 16, nw->arg_uint & 0xFFFF);
nl_send_group(m, cnt, nw->arg.group.proto, nw->arg.group.id);
return (true);
}
static bool
nlmsg_write_chain_buf(struct nl_writer *nw, void *buf, int datalen, int cnt)
{
struct mbuf **m0 = (struct mbuf **)(nw->arg_ptr);
NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg_ptr);
struct mbuf **m0 = (struct mbuf **)(nw->arg.ptr);
NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg.ptr);
if (__predict_false(datalen == 0)) {
free(buf, M_NETLINK);
@ -227,7 +228,7 @@ static bool
nlmsg_write_socket_mbuf(struct nl_writer *nw, void *buf, int datalen, int cnt)
{
struct mbuf *m = (struct mbuf *)buf;
NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg_ptr);
NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg.ptr);
if (__predict_false(datalen == 0)) {
m_freem(m);
@ -237,14 +238,15 @@ nlmsg_write_socket_mbuf(struct nl_writer *nw, void *buf, int datalen, int cnt)
m->m_pkthdr.len = datalen;
m->m_len = datalen;
int io_flags = (nw->ignore_limit) ? NL_IOF_IGNORE_LIMIT : 0;
return (nl_send_one(m, (struct nlpcb *)(nw->arg_ptr), cnt, io_flags));
return (nl_send_one(m, (struct nlpcb *)(nw->arg.ptr), cnt, io_flags));
}
static bool
nlmsg_write_group_mbuf(struct nl_writer *nw, void *buf, int datalen, int cnt)
{
struct mbuf *m = (struct mbuf *)buf;
NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg_ptr);
NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d proto: %d id: %d", buf, datalen,
nw->arg.group.proto, nw->arg.group.id);
if (__predict_false(datalen == 0)) {
m_freem(m);
@ -253,7 +255,7 @@ nlmsg_write_group_mbuf(struct nl_writer *nw, void *buf, int datalen, int cnt)
m->m_pkthdr.len = datalen;
m->m_len = datalen;
nl_send_group(m, cnt, nw->arg_uint >> 16, nw->arg_uint & 0xFFFF);
nl_send_group(m, cnt, nw->arg.group.proto, nw->arg.group.id);
return (true);
}
@ -261,9 +263,9 @@ static bool
nlmsg_write_chain_mbuf(struct nl_writer *nw, void *buf, int datalen, int cnt)
{
struct mbuf *m_new = (struct mbuf *)buf;
struct mbuf **m0 = (struct mbuf **)(nw->arg_ptr);
struct mbuf **m0 = (struct mbuf **)(nw->arg.ptr);
NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg_ptr);
NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg.ptr);
if (__predict_false(datalen == 0)) {
m_freem(m_new);
@ -324,7 +326,7 @@ nlmsg_write_socket_lbuf(struct nl_writer *nw, void *buf, int datalen, int cnt)
{
struct linear_buffer *lb = (struct linear_buffer *)buf;
char *data = (char *)(lb + 1);
struct nlpcb *nlp = (struct nlpcb *)(nw->arg_ptr);
struct nlpcb *nlp = (struct nlpcb *)(nw->arg.ptr);
if (__predict_false(datalen == 0)) {
free(buf, M_NETLINK);
@ -365,7 +367,7 @@ nlmsg_write_group_lbuf(struct nl_writer *nw, void *buf, int datalen, int cnt)
m_append(m, datalen, data);
free(buf, M_NETLINK);
nl_send_group(m, cnt, nw->arg_uint >> 16, nw->arg_uint & 0xFFFF);
nl_send_group(m, cnt, nw->arg.group.proto, nw->arg.group.id);
return (true);
}
@ -440,7 +442,7 @@ _nlmsg_get_unicast_writer(struct nl_writer *nw, int size, struct nlpcb *nlp)
{
if (!nlmsg_get_buf(nw, size, false, nlp->nl_linux))
return (false);
nw->arg_ptr = (void *)nlp;
nw->arg.ptr = (void *)nlp;
nw->writer_target = NS_WRITER_TARGET_SOCKET;
nlmsg_set_callback(nw);
return (true);
@ -451,7 +453,8 @@ _nlmsg_get_group_writer(struct nl_writer *nw, int size, int protocol, int group_
{
if (!nlmsg_get_buf(nw, size, false, false))
return (false);
nw->arg_uint = (uint64_t)protocol << 16 | (uint64_t)group_id;
nw->arg.group.proto = protocol;
nw->arg.group.id = group_id;
nw->writer_target = NS_WRITER_TARGET_GROUP;
nlmsg_set_callback(nw);
return (true);
@ -463,7 +466,7 @@ _nlmsg_get_chain_writer(struct nl_writer *nw, int size, struct mbuf **pm)
if (!nlmsg_get_buf(nw, size, false, false))
return (false);
*pm = NULL;
nw->arg_ptr = (void *)pm;
nw->arg.ptr = (void *)pm;
nw->writer_target = NS_WRITER_TARGET_CHAIN;
nlmsg_set_callback(nw);
NL_LOG(LOG_DEBUG3, "setup cb %p (need %p)", nw->cb, &nlmsg_write_chain_mbuf);
@ -542,7 +545,7 @@ _nlmsg_refill_buffer(struct nl_writer *nw, int required_len)
/* Update callback data */
ns_new.writer_target = nw->writer_target;
nlmsg_set_callback(&ns_new);
ns_new.arg_uint = nw->arg_uint;
ns_new.arg = nw->arg;
/* Copy last (unfinished) header to the new storage */
int last_len = nw->offset - completed_len;

9
sys/netlink/netlink_message_writer.h
View File

@ -49,9 +49,12 @@ struct nl_writer {
void *_storage; /* Underlying storage pointer */
nl_writer_cb *cb; /* Callback to flush data */
union {
void *arg_ptr; /* Callback argument as pointer */
uint64_t arg_uint; /* Callback argument as int */
};
void *ptr;
struct {
uint16_t proto;
uint16_t id;
} group;
} arg;
int num_messages; /* Number of messages in the buffer */
int malloc_flag; /* M_WAITOK or M_NOWAIT */
uint8_t writer_type; /* NS_WRITER_TYPE_* */