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| author | Maxime Devos <maximedevos@telenet.be> | 2021-02-14 12:57:32 +0100 |
|---|---|---|
| committer | Ludovic Courtès <ludo@gnu.org> | 2021-03-10 18:01:47 +0100 |
| commit | 520bac7ed00a949a0391ad680de65a1498105c2b (patch) | |
| tree | 15d2267b31ca62c0ef8b201aa700726aa310fa34 /gnu/services/authentication.scm | |
| parent | 1a1d0fe505da18c1f43996fb7eb3652e42250d0a (diff) | |
| download | guix-520bac7ed00a949a0391ad680de65a1498105c2b.tar.gz | |
services: Prevent following symlinks during activation.
This addresses a potential security issue, where a compromised service could trick the activation code in changing the permissions, owner and group of arbitrary files. However, this patch is currently only a partial fix, due to a TOCTTOU (time-of-check to time-of-use) race, which can be fixed once guile has bindings to openat and friends. Fixes: <https://lists.gnu.org/archive/html/guix-devel/2021-01/msg00388.html> * gnu/build/activation.scm: new procedure 'mkdir-p/perms'. * gnu/services/authentication.scm (%nslcd-activation, nslcd-service-type): use new procedure. * gnu/services/cups.scm (%cups-activation): likewise. * gnu/services/dbus.scm (dbus-activation): likewise. * gnu/services/dns.scm (knot-activation): likewise. Signed-off-by: Ludovic Courtès <ludo@gnu.org>
Diffstat (limited to 'gnu/services/authentication.scm')
| -rw-r--r-- | gnu/services/authentication.scm | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/gnu/services/authentication.scm b/gnu/services/authentication.scm index 73969a5a6d..d7efc48cd0 100644 --- a/gnu/services/authentication.scm +++ b/gnu/services/authentication.scm @@ -1,6 +1,7 @@ ;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2018 Danny Milosavljevic <dannym@scratchpost.org> ;;; Copyright © 2018, 2019 Ricardo Wurmus <rekado@elephly.net> +;;; Copyright © 2021 Maxime Devos <maximedevos@telenet.be> ;;; ;;; This file is part of GNU Guix. ;;; @@ -31,6 +32,7 @@ #:use-module (guix gexp) #:use-module (guix records) #:use-module (guix packages) + #:use-module (guix modules) #:use-module (ice-9 match) #:use-module (srfi srfi-1) #:use-module (srfi srfi-26) @@ -521,6 +523,16 @@ password.") (define (pam-ldap-pam-services config) (list (pam-ldap-pam-service config))) +(define %nslcd-activation + (with-imported-modules (source-module-closure '((gnu build activation))) + #~(begin + (use-modules (gnu build activation)) + (let ((rundir "/var/run/nslcd") + (user (getpwnam "nslcd"))) + (mkdir-p/perms rundir user #o755) + (when (file-exists? "/etc/nslcd.conf") + (chmod "/etc/nslcd.conf" #o400)))))) + (define nslcd-service-type (service-type (name 'nslcd) @@ -531,15 +543,7 @@ password.") (service-extension etc-service-type nslcd-etc-service) (service-extension activation-service-type - (const #~(begin - (use-modules (guix build utils)) - (let ((rundir "/var/run/nslcd") - (user (getpwnam "nslcd"))) - (mkdir-p rundir) - (chown rundir (passwd:uid user) (passwd:gid user)) - (chmod rundir #o755) - (when (file-exists? "/etc/nslcd.conf") - (chmod "/etc/nslcd.conf" #o400)))))) + (const %nslcd-activation)) (service-extension pam-root-service-type pam-ldap-pam-services) (service-extension nscd-service-type |