This commit fixes a race between port deletion and flow miss handling.
More specifically, a port could be removed while handling the flow
miss from it. If the flow requires slow path action, the handler
thread will try querying a pid from port's sockets. Since the port
has been deleted, the query will cause a dereference of NULL socket
pointer.
This commit makes the handler thread recheck the socket pointer before
dereferencing it.
VMware-BZ: 1251981
Reported-by: Pratap Reddy <pre...@nicira.com>
Signed-off-by: Alex Wang <al...@nicira.com>
---
lib/dpif-linux.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/lib/dpif-linux.c b/lib/dpif-linux.c
index 0eac3e7..b7495ce 100644
--- a/lib/dpif-linux.c
+++ b/lib/dpif-linux.c
@@ -831,7 +831,11 @@ dpif_linux_port_get_pid__(const struct dpif_linux *dpif,
odp_port_t port_no,
uint32_t idx = port_idx >= dpif->uc_array_size ? 0 : port_idx;
struct dpif_handler *h = &dpif->handlers[hash % dpif->n_handlers];
- pid = nl_sock_pid(h->channels[idx].sock);
+ /* Needs to check in case the socket pointer is changed in between
+ * of holding the locks. */
+ if (h->channels[idx].sock) {
+ pid = nl_sock_pid(h->channels[idx].sock);
+ }
}
return pid;
--
1.7.9.5
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