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SELinux: remap security classes on policyload and update audit log type#2131

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stefan11111 wants to merge 2 commits intoX11Libre:masterfrom
stefan11111:xorg-801
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SELinux: remap security classes on policyload and update audit log type#2131
stefan11111 wants to merge 2 commits intoX11Libre:masterfrom
stefan11111:xorg-801

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@stefan11111 stefan11111 commented Mar 15, 2026

Re-map the SELinux security classes on policy loads, as the mapping will
be desynchronized (see man:selinux_set_mapping(3)) and audit messages
will not show the actual class and permission names:

USER_AVC pid=24283 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:xorg_t:s0 msg='avc:  denied  { 0x10 } for request=XFIXES:SelectSelectionInput comm=/usr/bin/python3 resid=6400001 restype=WINDOW scontext=xuser_u:xuser_r:systemd_user_instance_generic_bin_t:s0 tcontext=xuser_u:object_r:xorg_t:s0 tclass=(null) permissive=1

In addition use type-safe assignments.

Use the appropriate audit type for SELINUX_ERROR, SELINUX_POLICYLOAD and
SELINUX_SETENFORCE libselinux messages, e.g. avoid USER_SELINUX_ERR for
policy load events:

audit[980]: USER_SELINUX_ERR pid=980 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:xorg_t:s0 msg='avc:  op=load_policy lsm=selinux seqno=8 res=1 exe="/usr/lib/xorg/Xorg" sauid=0 hostname=? addr=? terminal=?'

Do not generate an audit event for SELINUX_WARNING messages.

cgzones added 2 commits March 15, 2026 13:40
Re-map the SELinux security classes on policy loads, as the mapping will
be desynchronized (see man:selinux_set_mapping(3)) and audit messages
will not show the actual class and permission names:

    USER_AVC pid=24283 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:xorg_t:s0 msg='avc:  denied  { 0x10 } for request=XFIXES:SelectSelectionInput comm=/usr/bin/python3 resid=6400001 restype=WINDOW scontext=xuser_u:xuser_r:systemd_user_instance_generic_bin_t:s0 tcontext=xuser_u:object_r:xorg_t:s0 tclass=(null) permissive=1

In addition use type-safe assignments.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/801>
Only generate audit events for messages of the type avc (permission
denied) and error (e.g. invalid context).
For example avoid USER_SELINUX_ERR for policy load events:
    audit[980]: USER_SELINUX_ERR pid=980 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:xorg_t:s0 msg='avc:  op=load_policy lsm=selinux seqno=8 res=1 exe="/usr/lib/xorg/Xorg" sauid=0 hostname=? addr=? terminal=?'

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/801>
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