cmd: fix re-exec bug with classic confinement for host snapd < 2.28 #4176
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
Older version of snapd (before 2.28) did use the SNAPD_DID_REEXEC env to check if they should re-exec or not. We need to unset it after re-exec because the host snap tool may be old and using this key. So if e.g. the host has snapd 2.27 and snapd re-execs to 2.29 then `snap run --shell classic-snap` will go into an environment where the snapd 2.27 sees this key and stops re-execing and things break in suble ways. C.f. https://forum.snapcraft.io/t/seccomp-error-calling-snap-from-another-classic-snap-on-core-candidate/2736/7
mvo5
force-pushed
the
fix-did-reexec-on-classic
branch
from
ee41d6f
to
0640a95
Compare
zyga
approved these changes
Nov 8, 2017
Codecov Report
@@ Coverage Diff @@
## master #4176 +/- ##
==========================================
+ Coverage 75.53% 75.56% +0.02%
==========================================
Files 436 436
Lines 37811 37822 +11
==========================================
+ Hits 28562 28581 +19
+ Misses 7253 7245 -8
Partials 1996 1996
Continue to review full report at Codecov.
|
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
Older version of snapd (before 2.28) did use the SNAPD_DID_REEXEC
env to check if they should re-exec or not. We need
to unset it after re-exec because the host snap tool may be old and
using this key.
So if e.g. the host has snapd 2.27 and snapd re-execs to 2.29 then
snap run --shell classic-snapwill go into an environment where thesnapd 2.27 sees this key and stops re-execing and things break in
suble ways.
C.f.
https://forum.snapcraft.io/t/seccomp-error-calling-snap-from-another-classic-snap-on-core-candidate/2736/7