shared/idmap: handle "both" idmappings in raw.idmap properly #12718
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Imagine container created with:
lxc launch ubuntu:j c1 -c raw.idmap="both 1000 1000"
Then "volatile.last_state.idmap" will be like:
[
{"Isuid":true,"Isgid":false,"Hostid":1000000,"Nsid":0,"Maprange":1000},
{"Isuid":true,"Isgid":true,"Hostid":1000,"Nsid":1000,"Maprange":1}, // <-- our custom idmapping
{"Isuid":true,"Isgid":false,"Hostid":1001001,"Nsid":1001,"Maprange":999998999},
{"Isuid":false,"Isgid":true,"Hostid":1000000,"Nsid":0,"Maprange":1000},
{"Isuid":true,"Isgid":true,"Hostid":1000,"Nsid":1000,"Maprange":1}, // <-- oops, 2nd time!
{"Isuid":false,"Isgid":true,"Hostid":1001001,"Nsid":1001,"Maprange":999998999}
]
This makes idmapset.ToUidMappings() output incorrect (because mapping will be reported 2 times)
and breaks "lxc file push" functionality for containers with the root filesystem that doesn't support
idmapped mounts (because if it supports idmapped mounts then volatile.last_state.idmap will be []
anyways). That explains why Simon was able to reproduce that with ZFS but I wasn't able to reproduce
it with ext4-based "dir" storage driver.
Fixes: canonical#12507
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
|
@mihalicyn please can you add a test for this. |
|
I have added a test and validated that this test actually works and allows to reproduce the issue in our test environment. |
Big thanks to Simon Fels (@morphis) for providing us with a reproducer. Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
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Thanks! |
tomponline
approved these changes
Jan 18, 2024
mihalicyn
added a commit
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Apr 15, 2024
…mapping only if it's required
Fix diskAddRootUserNSEntry logic to correcly handle case when
we have not-groupped UID/GID mapping like this:
[{true false 1000 0 1} {false true 1000 0 1}]
because right now it assumes that mapping should be like
[{true true 1000 0 1}]
which is logically equivalent.
This become noticable after my change in canonical#12718, before that
this issue in logic was reproducible only if user will do something like this:
cat << EOF
uid $(id -u) 1000000
gid $(id -g) 1000000
EOF
) | lxc config set idmap raw.idmap -
which is an extremely rare usecase.
Fixes: canonical#13325
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
tomponline
pushed a commit
to tomponline/lxd
that referenced
this pull request
Apr 16, 2024
…mapping only if it's required
Fix diskAddRootUserNSEntry logic to correcly handle case when
we have not-groupped UID/GID mapping like this:
[{true false 1000 0 1} {false true 1000 0 1}]
because right now it assumes that mapping should be like
[{true true 1000 0 1}]
which is logically equivalent.
This become noticable after my change in canonical#12718, before that
this issue in logic was reproducible only if user will do something like this:
cat << EOF
uid $(id -u) 1000000
gid $(id -g) 1000000
EOF
) | lxc config set idmap raw.idmap -
which is an extremely rare usecase.
Fixes: canonical#13325
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
tomponline
pushed a commit
to tomponline/lxd
that referenced
this pull request
Apr 17, 2024
…mapping only if it's required
Fix diskAddRootUserNSEntry logic to correcly handle case when
we have not-groupped UID/GID mapping like this:
[{true false 1000 0 1} {false true 1000 0 1}]
because right now it assumes that mapping should be like
[{true true 1000 0 1}]
which is logically equivalent.
This become noticable after my change in canonical#12718, before that
this issue in logic was reproducible only if user will do something like this:
cat << EOF
uid $(id -u) 1000000
gid $(id -g) 1000000
EOF
) | lxc config set idmap raw.idmap -
which is an extremely rare usecase.
Fixes: canonical#13325
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
tomponline
pushed a commit
to tomponline/lxd
that referenced
this pull request
Apr 17, 2024
…mapping only if it's required
Fix diskAddRootUserNSEntry logic to correcly handle case when
we have not-groupped UID/GID mapping like this:
[{true false 1000 0 1} {false true 1000 0 1}]
because right now it assumes that mapping should be like
[{true true 1000 0 1}]
which is logically equivalent.
This become noticable after my change in canonical#12718, before that
this issue in logic was reproducible only if user will do something like this:
cat << EOF
uid $(id -u) 1000000
gid $(id -g) 1000000
EOF
) | lxc config set idmap raw.idmap -
which is an extremely rare usecase.
Fixes: canonical#13325
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
hamistao
pushed a commit
to hamistao/lxd
that referenced
this pull request
Apr 18, 2024
…mapping only if it's required
Fix diskAddRootUserNSEntry logic to correcly handle case when
we have not-groupped UID/GID mapping like this:
[{true false 1000 0 1} {false true 1000 0 1}]
because right now it assumes that mapping should be like
[{true true 1000 0 1}]
which is logically equivalent.
This become noticable after my change in canonical#12718, before that
this issue in logic was reproducible only if user will do something like this:
cat << EOF
uid $(id -u) 1000000
gid $(id -g) 1000000
EOF
) | lxc config set idmap raw.idmap -
which is an extremely rare usecase.
Fixes: canonical#13325
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
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Imagine container created with:
lxc launch ubuntu:j c1 -c raw.idmap="both 1000 1000"
Then "volatile.last_state.idmap" will be like:
[
{"Isuid":true,"Isgid":false,"Hostid":1000000,"Nsid":0,"Maprange":1000},
{"Isuid":true,"Isgid":true,"Hostid":1000,"Nsid":1000,"Maprange":1}, // <-- our custom idmapping
{"Isuid":true,"Isgid":false,"Hostid":1001001,"Nsid":1001,"Maprange":999998999},
{"Isuid":false,"Isgid":true,"Hostid":1000000,"Nsid":0,"Maprange":1000},
{"Isuid":true,"Isgid":true,"Hostid":1000,"Nsid":1000,"Maprange":1}, // <-- oops, 2nd time!
{"Isuid":false,"Isgid":true,"Hostid":1001001,"Nsid":1001,"Maprange":999998999}
]
This makes idmapset.ToUidMappings() output incorrect (because mapping will be reported 2 times) and breaks "lxc file push" functionality for containers with the root filesystem that doesn't support idmapped mounts (because if it supports idmapped mounts then volatile.last_state.idmap will be [] anyways). That explains why Simon was able to reproduce that with ZFS but I wasn't able to reproduce it with ext4-based "dir" storage driver.
Fixes: #12507