Add O_PATH support in vfs2

PiperOrigin-RevId: 354367665

3 files changed, 21 insertions, 0 deletions

diff --git a/pkg/sentry/syscalls/linux/vfs2/fd.go b/pkg/sentry/syscalls/linux/vfs2/fd.go
index e39f074f2..1a31898e8 100644
--- a/pkg/sentry/syscalls/linux/vfs2/fd.go
+++ b/pkg/sentry/syscalls/linux/vfs2/fd.go
@@ -123,6 +123,15 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
 	}
 	defer file.DecRef(t)
 
+	if file.StatusFlags()&linux.O_PATH != 0 {
+		switch cmd {
+		case linux.F_DUPFD, linux.F_DUPFD_CLOEXEC, linux.F_GETFD, linux.F_SETFD, linux.F_GETFL:
+			// allowed
+		default:
+			return 0, nil, syserror.EBADF
+		}
+	}
+
 	switch cmd {
 	case linux.F_DUPFD, linux.F_DUPFD_CLOEXEC:
 		minfd := args[2].Int()
@@ -395,6 +404,10 @@ func Fadvise64(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys
 	}
 	defer file.DecRef(t)
 
+	if file.StatusFlags()&linux.O_PATH != 0 {
+		return 0, nil, syserror.EBADF
+	}
+
 	// If the FD refers to a pipe or FIFO, return error.
 	if _, isPipe := file.Impl().(*pipe.VFSPipeFD); isPipe {
 		return 0, nil, syserror.ESPIPE
diff --git a/pkg/sentry/syscalls/linux/vfs2/ioctl.go b/pkg/sentry/syscalls/linux/vfs2/ioctl.go
index 20c264fef..c7c3fed57 100644
--- a/pkg/sentry/syscalls/linux/vfs2/ioctl.go
+++ b/pkg/sentry/syscalls/linux/vfs2/ioctl.go
@@ -32,6 +32,10 @@ func Ioctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
 	}
 	defer file.DecRef(t)
 
+	if file.StatusFlags()&linux.O_PATH != 0 {
+		return 0, nil, syserror.EBADF
+	}
+
 	// Handle ioctls that apply to all FDs.
 	switch args[1].Int() {
 	case linux.FIONCLEX:
diff --git a/pkg/sentry/syscalls/linux/vfs2/sync.go b/pkg/sentry/syscalls/linux/vfs2/sync.go
index 6e9b599e2..1f8a5878c 100644
--- a/pkg/sentry/syscalls/linux/vfs2/sync.go
+++ b/pkg/sentry/syscalls/linux/vfs2/sync.go
@@ -36,6 +36,10 @@ func Syncfs(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
 	}
 	defer file.DecRef(t)
 
+	if file.StatusFlags()&linux.O_PATH != 0 {
+		return 0, nil, syserror.EBADF
+	}
+
 	return 0, nil, file.SyncFS(t)
 }