[v4.4] Match VT device paths to be blocked from mounting exactly #17272
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
As @mheon pointed out in PR containers#17055[^1], isVirtualConsoleDevice() does not only matches VT device paths but also devices named like /dev/tty0abcd. This causes that non VT device paths named /dev/tty[0-9]+[A-Za-z]+ are not mounted into privileged container and systemd containers accidentally. This is an unlikely issue because the Linux kernel does not use device paths like that. To make it failproof and prevent issues in unlikely scenarios, change isVirtualConsoleDevice() to exactly match ^/dev/tty[0-9]+$ paths. Because it is not possible to match this path exactly with Glob syntax, the path is now checked with strings.TrimPrefix() and strconv.ParseUint(). ParseUint uses a bitsize of 16, this is sufficient because the max number of TTY devices is 512 in Linux 6.1.5. (Checked via 'git grep -e '#define' --and -e 'TTY_MINORS'). The commit also adds a unit-test for isVirtualConsoleDevice(). Fixes: f4c81b0 ("Only prevent VTs to be mounted inside...") [^1]: containers#17055 (comment) Signed-off-by: Fabian Holler <mail@fholler.de> Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
openshift-ci
bot
added
lgtm
|
[APPROVALNOTIFIER] This PR is APPROVED This pull-request has been approved by: openshift-cherrypick-robot, vrothberg The full list of commands accepted by this bot can be found here. The pull request process is described here
Needs approval from an approver in each of these files:
Approvers can indicate their approval by writing |
openshift-ci
bot
added
the
approved
|
/hold cancel |
openshift-ci
bot
removed
the
do-not-merge/hold
github-actions
bot
added
the
locked - please file new issue/PR
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This is an automated cherry-pick of #17265
/assign vrothberg