From a5338d9cd2efcf914ba78edfe2615c7c0657b157 Mon Sep 17 00:00:00 2001
From: Aleksandr Nogikh <nogikh@google.com>
Date: Mon, 6 Dec 2021 11:30:24 +0000
Subject: executor: spread overlapping fds

There's a chance that the methods from common_bsd.h and common_linux.h
could dup2 (and thus close) an fd belonging to a kcov instance.

Prevent this by adjusting fd consts.
---
 executor/common_bsd.h    | 2 +-
 executor/common_linux.h  | 6 +++---
 pkg/csource/generated.go | 8 ++++----
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/executor/common_bsd.h b/executor/common_bsd.h
index 332e68e5f..7293df993 100644
--- a/executor/common_bsd.h
+++ b/executor/common_bsd.h
@@ -230,7 +230,7 @@ static void initialize_tun(int tun_id)
 	}
 	// Remap tun onto higher fd number to hide it from fuzzer and to keep
 	// fd numbers stable regardless of whether tun is opened or not (also see kMaxFd).
-	const int kTunFd = 240;
+	const int kTunFd = 200;
 	if (dup2(tunfd, kTunFd) < 0)
 		fail("dup2(tunfd, kTunFd) failed");
 	close(tunfd);
diff --git a/executor/common_linux.h b/executor/common_linux.h
index 7df9476eb..cbf311b22 100644
--- a/executor/common_linux.h
+++ b/executor/common_linux.h
@@ -567,7 +567,7 @@ static void initialize_tun(void)
 	}
 	// Remap tun onto higher fd number to hide it from fuzzer and to keep
 	// fd numbers stable regardless of whether tun is opened or not (also see kMaxFd).
-	const int kTunFd = 240;
+	const int kTunFd = 200;
 	if (dup2(tunfd, kTunFd) < 0)
 		fail("dup2(tunfd, kTunFd) failed");
 	close(tunfd);
@@ -632,7 +632,7 @@ static void initialize_tun(void)
 #endif
 
 #if SYZ_EXECUTOR || __NR_syz_init_net_socket || SYZ_DEVLINK_PCI
-const int kInitNetNsFd = 239; // see kMaxFd
+const int kInitNetNsFd = 201; // see kMaxFd
 #endif
 
 #if SYZ_EXECUTOR || SYZ_DEVLINK_PCI || SYZ_NET_DEVICES
@@ -2582,7 +2582,7 @@ static void initialize_vhci()
 
 	// Remap vhci onto higher fd number to hide it from fuzzer and to keep
 	// fd numbers stable regardless of whether vhci is opened or not (also see kMaxFd).
-	const int kVhciFd = 241;
+	const int kVhciFd = 202;
 	if (dup2(vhci_fd, kVhciFd) < 0)
 		fail("dup2(vhci_fd, kVhciFd) failed");
 	close(vhci_fd);
diff --git a/pkg/csource/generated.go b/pkg/csource/generated.go
index b914f3048..728806967 100644
--- a/pkg/csource/generated.go
+++ b/pkg/csource/generated.go
@@ -1757,7 +1757,7 @@ static void initialize_tun(int tun_id)
 		return;
 #endif
 	}
-	const int kTunFd = 240;
+	const int kTunFd = 200;
 	if (dup2(tunfd, kTunFd) < 0)
 		fail("dup2(tunfd, kTunFd) failed");
 	close(tunfd);
@@ -2823,7 +2823,7 @@ static void initialize_tun(void)
 		return;
 #endif
 	}
-	const int kTunFd = 240;
+	const int kTunFd = 200;
 	if (dup2(tunfd, kTunFd) < 0)
 		fail("dup2(tunfd, kTunFd) failed");
 	close(tunfd);
@@ -2875,7 +2875,7 @@ static void initialize_tun(void)
 #endif
 
 #if SYZ_EXECUTOR || __NR_syz_init_net_socket || SYZ_DEVLINK_PCI
-const int kInitNetNsFd = 239;
+const int kInitNetNsFd = 201;
 #endif
 
 #if SYZ_EXECUTOR || SYZ_DEVLINK_PCI || SYZ_NET_DEVICES
@@ -5973,7 +5973,7 @@ static void initialize_vhci()
 	vhci_fd = open("/dev/vhci", O_RDWR);
 	if (vhci_fd == -1)
 		fail("open /dev/vhci failed");
-	const int kVhciFd = 241;
+	const int kVhciFd = 202;
 	if (dup2(vhci_fd, kVhciFd) < 0)
 		fail("dup2(vhci_fd, kVhciFd) failed");
 	close(vhci_fd);
-- 
cgit mrf-deployment