From 8d168f33486951c7121b923bd28ce5d4a9494099 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barnab=C3=A1s=20P=C5=91cze?=
 <barnabas.pocze@ideasonboard.com>
Date: Mon, 24 Mar 2025 16:05:44 +0100
Subject: [PATCH] libcamera: process: Ensure that file descriptors are
 nonnegative
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Return `-EINVAL` from `Process::start()` if any of the file descriptors
are negative as those most likely signal some kind of issue such as
missed error checking.

Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 src/libcamera/process.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/libcamera/process.cpp b/src/libcamera/process.cpp
index edbe8664a..0eae68072 100644
--- a/src/libcamera/process.cpp
+++ b/src/libcamera/process.cpp
@@ -243,6 +243,11 @@ int Process::start(const std::string &path,
 	if (running_)
 		return -EBUSY;
 
+	for (int fd : fds) {
+		if (fd < 0)
+			return -EINVAL;
+	}
+
 	int childPid = fork();
 	if (childPid == -1) {
 		ret = -errno;
@@ -298,6 +303,8 @@ void Process::closeAllFdsExcept(const std::vector<int> &fds)
 	std::vector<int> v(fds);
 	sort(v.begin(), v.end());
 
+	ASSERT(v.empty() || v.front() >= 0);
+
 	DIR *dir = opendir("/proc/self/fd");
 	if (!dir)
 		return;