util: explicitly chmod generated files to enforce permissions - #614
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When netplan generate is executed under a restrictive umask (such as 0077), files written by g_file_set_contents_full() end up with mode 0600 instead of 0640. This prevents systemd-networkd from reading the generated .network files, breaking network configuration. Explicitly call chmod() after chown() so target permissions are guaranteed regardless of the caller's umask. Also add a unit test in test_netplan_misc to verify file creation under a restrictive umask. LP: #2164636 Signed-off-by: Viktor Pashaiev <w.paszajew@gmail.com>
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@vpashaiev Thanks for the PR
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When
netplan generateruns under a restrictive umask (such as0077), files created byg_file_set_contents_full()end up with permissions0600instead of0640. As a result,systemd-networkd(running unprivileged assystemd-network:systemd-network) cannot read/run/systemd/network/10-netplan-*.network, causing network configuration to fail on boot.This PR explicitly calls
chmod()afterchown()in_netplan_g_string_free_to_file_with_permissions()so that the intended file mode is enforced regardless of the caller's umask. It also adds a unit test intest_netplan_miscto verify file permissions under umask0077.Addresses feedback from @puida on Launchpad #2164636.
Fixes: https://bugs.launchpad.net/ubuntu/+source/netplan.io/+bug/2164636