From e05f7c55d78b90062aad26d8badc689ea72fe88b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= Date: Thu, 8 Sep 2022 14:30:19 +0200 Subject: file-systems: Open files with O_CLOEXEC. Since this code is run from PID 1, this ensures file descriptors to sensitive files and devices are not accidentally leaked to sub-processes. * gnu/build/file-systems.scm (call-with-input-file): New procedure. (mount-file-system): Use 'close-fdes' + 'open-fdes'. --- gnu/build/file-systems.scm | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'gnu/build') diff --git a/gnu/build/file-systems.scm b/gnu/build/file-systems.scm index b9d46c9350..0ed5dc5671 100644 --- a/gnu/build/file-systems.scm +++ b/gnu/build/file-systems.scm @@ -98,6 +98,18 @@ standard input is /dev/null." system*/console) program args)) +(define (call-with-input-file file proc) + "Like 'call-with-input-file', but pass O_CLOEXEC." + (let ((port #f)) + (dynamic-wind + (lambda () + (set! port (open file (logior O_RDONLY O_CLOEXEC)))) + (lambda () + (proc port)) + (lambda () + (close-port port) + (set! port #f))))) + (define (bind-mount source target) "Bind-mount SOURCE at TARGET." (mount source target "" MS_BIND)) @@ -1183,7 +1195,8 @@ corresponds to the symbols listed in FLAGS." (not (file-is-directory? source))) (unless (file-exists? target) (mkdir-p (dirname target)) - (call-with-output-file target (const #t))) + (close-fdes + (open-fdes target (logior O_WRONLY O_CREAT O_CLOEXEC)))) (mkdir-p target)) (cond -- cgit v1.2.3