libcamera: ipc_unixsocket: Do not run memcpy with null arguments

In IPCUnixSocket, a payload can be sent/received with empty fd vector,
which leads to passing a nullptr in memcpy() in both sendData()
and recvData(). Add a null check for fd vector's data pointer
to avoid invoking memcpy() with nullptr.

The issue is noticed by running a test manually testing the vimc
IPA code paths in isolated mode. It is only noticed when the test
is compiled with -Db_sanitize=address,undefined meson built-in option.

ipc_unixsocket.cpp:268:8: runtime error: null pointer passed as argument 2, which is declared to never be null
ipc_unixsocket.cpp:312:8: runtime error: null pointer passed as argument 1, which is declared to never be null

Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/libcamera/ipc_unixsocket.cpp b/src/libcamera/ipc_unixsocket.cpp
index a4ab1a5f..7188cf29 100644
--- a/src/libcamera/ipc_unixsocket.cpp
+++ b/src/libcamera/ipc_unixsocket.cpp
@@ -260,7 +260,8 @@ int IPCUnixSocket::sendData(const void *buffer, size_t length,
 	msg.msg_control = cmsg;
 	msg.msg_controllen = cmsg->cmsg_len;
 	msg.msg_flags = 0;
-	memcpy(CMSG_DATA(cmsg), fds, num * sizeof(uint32_t));
+	if (fds)
+		memcpy(CMSG_DATA(cmsg), fds, num * sizeof(uint32_t));
 
 	if (sendmsg(fd_, &msg, 0) < 0) {
 		int ret = -errno;
@@ -304,7 +305,8 @@ int IPCUnixSocket::recvData(void *buffer, size_t length,
 		return ret;
 	}
 
-	memcpy(fds, CMSG_DATA(cmsg), num * sizeof(uint32_t));
+	if (fds)
+		memcpy(fds, CMSG_DATA(cmsg), num * sizeof(uint32_t));
 
 	return 0;
 }