Protect against DPDK crash when allocation of listen fd >= 1023. For events on fd:s >1023, the current implementation will trigger an abort due to access outside of allocated bit mask.
Corrections would include: * Match fdset_add() signature in fd_man.c to fd_man.h * Handling of return codes from fdset_add() * Addition of check of fd number in fdset_add_fd() --- The rationale behind the suggested code change is that, fdset_event_dispatch() could attempt access outside of the FD_SET bitmask if there is an event on a file descriptor that in turn looks up a virtio file descriptor with a value > 1023. Such an attempt will lead to an abort() and a restart of any vswitch using DPDK. A discussion topic exist in the ovs-discuss mailing list that can provide a little more background: http://openvswitch.org/pipermail/discuss/2016-February/020243.html Signed-off-by: Patrik Andersson <patrik.r.andersson at ericsson.com> --- lib/librte_vhost/vhost_user/fd_man.c | 11 ++++++----- lib/librte_vhost/vhost_user/vhost-net-user.c | 22 ++++++++++++++++++++-- 2 files changed, 26 insertions(+), 7 deletions(-) diff --git a/lib/librte_vhost/vhost_user/fd_man.c b/lib/librte_vhost/vhost_user/fd_man.c index 087aaed..c691339 100644 --- a/lib/librte_vhost/vhost_user/fd_man.c +++ b/lib/librte_vhost/vhost_user/fd_man.c @@ -71,20 +71,22 @@ fdset_find_free_slot(struct fdset *pfdset) return fdset_find_fd(pfdset, -1); } -static void +static int fdset_add_fd(struct fdset *pfdset, int idx, int fd, fd_cb rcb, fd_cb wcb, void *dat) { struct fdentry *pfdentry; - if (pfdset == NULL || idx >= MAX_FDS) - return; + if (pfdset == NULL || idx >= MAX_FDS || fd >= FD_SETSIZE) + return -1; pfdentry = &pfdset->fd[idx]; pfdentry->fd = fd; pfdentry->rcb = rcb; pfdentry->wcb = wcb; pfdentry->dat = dat; + + return 0; } /** @@ -150,12 +152,11 @@ fdset_add(struct fdset *pfdset, int fd, fd_cb rcb, fd_cb wcb, void *dat) /* Find a free slot in the list. */ i = fdset_find_free_slot(pfdset); - if (i == -1) { + if (i == -1 || fdset_add_fd(pfdset, i, fd, rcb, wcb, dat) < 0) { pthread_mutex_unlock(&pfdset->fd_mutex); return -2; } - fdset_add_fd(pfdset, i, fd, rcb, wcb, dat); pfdset->num++; pthread_mutex_unlock(&pfdset->fd_mutex); diff --git a/lib/librte_vhost/vhost_user/vhost-net-user.c b/lib/librte_vhost/vhost_user/vhost-net-user.c index df2bd64..778851d 100644 --- a/lib/librte_vhost/vhost_user/vhost-net-user.c +++ b/lib/librte_vhost/vhost_user/vhost-net-user.c @@ -288,6 +288,7 @@ vserver_new_vq_conn(int fd, void *dat, __rte_unused int *remove) int fh; struct vhost_device_ctx vdev_ctx = { (pid_t)0, 0 }; unsigned int size; + int ret; conn_fd = accept(fd, NULL, NULL); RTE_LOG(INFO, VHOST_CONFIG, @@ -317,8 +318,15 @@ vserver_new_vq_conn(int fd, void *dat, __rte_unused int *remove) ctx->vserver = vserver; ctx->fh = fh; - fdset_add(&g_vhost_server.fdset, + ret = fdset_add(&g_vhost_server.fdset, conn_fd, vserver_message_handler, NULL, ctx); + if (ret < 0) { + free(ctx); + close(conn_fd); + RTE_LOG(ERR, VHOST_CONFIG, + "failed to add fd %d into vhost server fdset\n", + conn_fd); + } } /* callback when there is message on the connfd */ @@ -453,6 +461,7 @@ int rte_vhost_driver_register(const char *path) { struct vhost_server *vserver; + int ret; pthread_mutex_lock(&g_vhost_server.server_mutex); @@ -478,8 +487,17 @@ rte_vhost_driver_register(const char *path) vserver->path = strdup(path); - fdset_add(&g_vhost_server.fdset, vserver->listenfd, + ret = fdset_add(&g_vhost_server.fdset, vserver->listenfd, vserver_new_vq_conn, NULL, vserver); + if (ret < 0) { + pthread_mutex_unlock(&g_vhost_server.server_mutex); + RTE_LOG(ERR, VHOST_CONFIG, + "failed to add listen fd %d to vhost server fdset\n", + vserver->listenfd); + free(vserver->path); + free(vserver); + return -1; + } g_vhost_server.server[g_vhost_server.vserver_cnt++] = vserver; pthread_mutex_unlock(&g_vhost_server.server_mutex); -- 1.9.1
