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contrib/rdmacm-mux: Fix out-of-bounds risk

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The function get_fd extract context from the received MAD message and
uses it as a key to fetch the destination fd from the mapping table.
A context can be dgid in case of CM request message or comm_id in case
of CM SIDR response message.

When MAD message with a smaller size as expected for the message type
received we are hitting out-of-bounds where we are looking for the
context out of message boundaries.

Fix it by validating the message size.

Reported-by Sam Smith <sam.j.smith@oracle.com>
Signed-off-by: Yuval Shaia <yuval.shaia@oracle.com>
Message-Id: <20190212112347.1605-1-yuval.shaia@oracle.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
This commit is contained in:
Yuval Shaia 2019-02-12 13:23:47 +02:00 committed by Marcel Apfelbaum
parent 8b088d3f8a
commit ade0075523
1 changed files with 33 additions and 2 deletions
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35
contrib/rdmacm-mux/main.c
View File

@ -300,7 +300,7 @@ static void hash_tbl_remove_fd_ifid_pair(int fd)
pthread_rwlock_unlock(&server.lock); pthread_rwlock_unlock(&server.lock);
} }
static int get_fd(const char *mad, int *fd, __be64 *gid_ifid) static int get_fd(const char *mad, int umad_len, int *fd, __be64 *gid_ifid)
{ {
struct umad_hdr *hdr = (struct umad_hdr *)mad; struct umad_hdr *hdr = (struct umad_hdr *)mad;
char *data = (char *)hdr + sizeof(*hdr); char *data = (char *)hdr + sizeof(*hdr);
@ -308,13 +308,35 @@ static int get_fd(const char *mad, int *fd, __be64 *gid_ifid)
uint16_t attr_id = be16toh(hdr->attr_id); uint16_t attr_id = be16toh(hdr->attr_id);
int rc = 0; int rc = 0;
if (umad_len <= sizeof(*hdr)) {
rc = -EINVAL;
syslog(LOG_DEBUG, "Ignoring MAD packets with header only\n");
goto out;
}
switch (attr_id) { switch (attr_id) {
case UMAD_CM_ATTR_REQ: case UMAD_CM_ATTR_REQ:
if (unlikely(umad_len < sizeof(*hdr) + CM_REQ_DGID_POS +
sizeof(*gid_ifid))) {
rc = -EINVAL;
syslog(LOG_WARNING,
"Invalid MAD packet size (%d) for attr_id 0x%x\n", umad_len,
attr_id);
goto out;
}
memcpy(gid_ifid, data + CM_REQ_DGID_POS, sizeof(*gid_ifid)); memcpy(gid_ifid, data + CM_REQ_DGID_POS, sizeof(*gid_ifid));
rc = hash_tbl_search_fd_by_ifid(fd, gid_ifid); rc = hash_tbl_search_fd_by_ifid(fd, gid_ifid);
break; break;
case UMAD_CM_ATTR_SIDR_REQ: case UMAD_CM_ATTR_SIDR_REQ:
if (unlikely(umad_len < sizeof(*hdr) + CM_SIDR_REQ_DGID_POS +
sizeof(*gid_ifid))) {
rc = -EINVAL;
syslog(LOG_WARNING,
"Invalid MAD packet size (%d) for attr_id 0x%x\n", umad_len,
attr_id);
goto out;
}
memcpy(gid_ifid, data + CM_SIDR_REQ_DGID_POS, sizeof(*gid_ifid)); memcpy(gid_ifid, data + CM_SIDR_REQ_DGID_POS, sizeof(*gid_ifid));
rc = hash_tbl_search_fd_by_ifid(fd, gid_ifid); rc = hash_tbl_search_fd_by_ifid(fd, gid_ifid);
break; break;
@ -331,6 +353,13 @@ static int get_fd(const char *mad, int *fd, __be64 *gid_ifid)
data += sizeof(comm_id); data += sizeof(comm_id);
/* Fall through */ /* Fall through */
case UMAD_CM_ATTR_SIDR_REP: case UMAD_CM_ATTR_SIDR_REP:
if (unlikely(umad_len < sizeof(*hdr) + sizeof(comm_id))) {
rc = -EINVAL;
syslog(LOG_WARNING,
"Invalid MAD packet size (%d) for attr_id 0x%x\n", umad_len,
attr_id);
goto out;
}
memcpy(&comm_id, data, sizeof(comm_id)); memcpy(&comm_id, data, sizeof(comm_id));
if (comm_id) { if (comm_id) {
rc = hash_tbl_search_fd_by_comm_id(comm_id, fd, gid_ifid); rc = hash_tbl_search_fd_by_comm_id(comm_id, fd, gid_ifid);
@ -344,6 +373,7 @@ static int get_fd(const char *mad, int *fd, __be64 *gid_ifid)
syslog(LOG_DEBUG, "mad_to_vm: %d 0x%x 0x%x\n", *fd, attr_id, comm_id); syslog(LOG_DEBUG, "mad_to_vm: %d 0x%x 0x%x\n", *fd, attr_id, comm_id);
out:
return rc; return rc;
} }
@ -372,7 +402,8 @@ static void *umad_recv_thread_func(void *args)
} while (rc && server.run); } while (rc && server.run);
if (server.run) { if (server.run) {
rc = get_fd(msg.umad.mad, &fd, &msg.hdr.sgid.global.interface_id); rc = get_fd(msg.umad.mad, msg.umad_len, &fd,
&msg.hdr.sgid.global.interface_id);
if (rc) { if (rc) {
continue; continue;
} }