Prevent file descriptor leaks across exec#48
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When spawning native processes, cpproc_forkAndExec() only closes the file descriptors created for the current spawn, allowing other JVM descriptors not marked FD_CLOEXEC to leak into the executed process. This can keep unrelated files, sockets and process pipes open unexpectedly. Fix by marking all non-standard descriptors close-on-exec in the forked child just before exec(). Several strategies are implemented: - Prefer close_range(CLOSE_RANGE_CLOEXEC) if available - Enumerate open fds by walking the platform-specific process fd directory - Fall back to a bounded fcntl scan. The scan limit is computed in the parent to avoid calling sysconf() in the child, and is capped at 65536 if the limit is unknown or too high. The exec-failure pipe is covered by the sweep, so its explicit FD_CLOEXEC fcntl becomes redundant and is dropped. Fixes #46 (BZ#126300) Fixes #47 (BZ#31384) Signed-off-by: Guillermo Rodríguez <grodriguez@ingelabs.com>
Clarify why setting FD_CLOEXEC on the directory stream fd is safe. Signed-off-by: Guillermo Rodríguez <grodriguez@ingelabs.com>
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When spawning native processes, cpproc_forkAndExec() only closes the file descriptors created for the current spawn, allowing other JVM descriptors not marked FD_CLOEXEC to leak into the executed process. This can keep unrelated files, sockets and process pipes open unexpectedly.
Fix by marking all non-standard descriptors close-on-exec in the forked child just before exec(). Several strategies are implemented:
The exec-failure pipe is covered by the sweep, so its explicit FD_CLOEXEC fcntl becomes redundant and is dropped.
Fixes #46 (BZ#126300)
Fixes #47 (BZ#31384)