diff options
| -rw-r--r-- | doc/guix.texi | 15 | ||||
| -rw-r--r-- | guix/channels.scm | 36 | ||||
| -rw-r--r-- | guix/scripts/pull.scm | 35 |
3 files changed, 67 insertions, 19 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index aa2b316c90..3d1b097447 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -3900,6 +3900,21 @@ Use @var{profile} instead of @file{~/.config/guix/current}. Show which channel commit(s) would be used and what would be built or substituted but do not actually do it. +@item --allow-downgrades +Allow pulling older or unrelated revisions of channels than those +currently in use. + +@cindex downgrade attacks, protection against +By default, @command{guix pull} protects against so-called ``downgrade +attacks'' whereby the Git repository of a channel would be reset to an +earlier or unrelated revision of itself, potentially leading you to +install older, known-vulnerable versions of software packages. + +@quotation Note +Make sure you understand its security implications before using +@option{--allow-downgrades}. +@end quotation + @item --system=@var{system} @itemx -s @var{system} Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of diff --git a/guix/channels.scm b/guix/channels.scm index 70e2d7f07c..84c47fc0d0 100644 --- a/guix/channels.scm +++ b/guix/channels.scm @@ -246,25 +246,29 @@ This procedure implements a channel update policy meant to be used as a ('ancestor #t) ('self #t) (_ - (raise (apply make-compound-condition - (condition - (&message (message - (format #f (G_ "\ + (raise (make-compound-condition + (condition + (&message (message + (format #f (G_ "\ aborting update of channel '~a' to commit ~a, which is not a descendant of ~a") - (channel-name channel) - (channel-instance-commit instance) - start)))) - - ;; Don't show the hint when the user explicitly specified a - ;; commit in CHANNEL. - (if (channel-commit channel) - '() - (list (condition - (&fix-hint - (hint (G_ "This could indicate that the channel has + (channel-name channel) + (channel-instance-commit instance) + start)))) + + ;; If the user asked for a specific commit, they might want + ;; that to happen nevertheless, so tell them about the + ;; relevant 'guix pull' option. + (if (channel-commit channel) + (condition + (&fix-hint + (hint (G_ "Use @option{--allow-downgrades} to force +this downgrade.")))) + (condition + (&fix-hint + (hint (G_ "This could indicate that the channel has been tampered with and is trying to force a roll-back, preventing you from getting the latest updates. If you think this is not the case, explicitly -allow non-forward updates."))))))))))) +allow non-forward updates.")))))))))) (define* (latest-channel-instances store channels #:key diff --git a/guix/scripts/pull.scm b/guix/scripts/pull.scm index dfe7ee7ad5..c386d81b8e 100644 --- a/guix/scripts/pull.scm +++ b/guix/scripts/pull.scm @@ -81,7 +81,8 @@ (multiplexed-build-output? . #t) (graft? . #t) (debug . 0) - (verbosity . 1))) + (verbosity . 1) + (validate-pull . ,ensure-forward-channel-update))) (define (show-help) (display (G_ "Usage: guix pull [OPTION]... @@ -95,6 +96,8 @@ Download and deploy the latest version of Guix.\n")) (display (G_ " --branch=BRANCH download the tip of the specified BRANCH")) (display (G_ " + --allow-downgrades allow downgrades to earlier channel revisions")) + (display (G_ " -N, --news display news compared to the previous generation")) (display (G_ " -l, --list-generations[=PATTERN] @@ -158,6 +161,10 @@ Download and deploy the latest version of Guix.\n")) (option '("branch") #t #f (lambda (opt name arg result) (alist-cons 'ref `(branch . ,arg) result))) + (option '("allow-downgrades") #f #f + (lambda (opt name arg result) + (alist-cons 'validate-pull warn-about-backward-updates + result))) (option '(#\p "profile") #t #f (lambda (opt name arg result) (alist-cons 'profile (canonicalize-profile arg) @@ -188,6 +195,21 @@ Download and deploy the latest version of Guix.\n")) %standard-build-options)) +(define (warn-about-backward-updates channel start instance relation) + "Warn about non-forward updates of CHANNEL from START to INSTANCE, without +aborting." + (match relation + ((or 'ancestor 'self) + #t) + ('descendant + (warning (G_ "rolling back channel '~a' from ~a to ~a~%") + (channel-name channel) start + (channel-instance-commit instance))) + ('unrelated + (warning (G_ "moving channel '~a' from ~a to unrelated commit ~a~%") + (channel-name channel) start + (channel-instance-commit instance))))) + (define* (display-profile-news profile #:key concise? current-is-newer?) "Display what's up in PROFILE--new packages, and all that. If @@ -749,7 +771,9 @@ Use '~/.config/guix/channels.scm' instead.")) (substitutes? (assoc-ref opts 'substitutes?)) (dry-run? (assoc-ref opts 'dry-run?)) (channels (channel-list opts)) - (profile (or (assoc-ref opts 'profile) %current-profile))) + (profile (or (assoc-ref opts 'profile) %current-profile)) + (current-channels (profile-channels profile)) + (validate-pull (assoc-ref opts 'validate-pull))) (cond ((assoc-ref opts 'query) (process-query opts profile)) ((assoc-ref opts 'generation) @@ -766,7 +790,12 @@ Use '~/.config/guix/channels.scm' instead.")) (ensure-default-profile) (honor-x509-certificates store) - (let ((instances (latest-channel-instances store channels))) + (let ((instances + (latest-channel-instances store channels + #:current-channels + current-channels + #:validate-pull + validate-pull))) (format (current-error-port) (N_ "Building from this channel:~%" "Building from these channels:~%" |