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path: root/security/apparmor/af_unix.c
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2025-07-20apparmor: transition from a list of rules to a vector of rulesJohn Johansen
The set of rules on a profile is not dynamically extended, instead if a new ruleset is needed a new version of the profile is created. This allows us to use a vector of rules instead of a list, slightly reducing memory usage and simplifying the code. Signed-off-by: John Johansen <john.johansen@canonical.com>
2025-07-20apparmor: shift uid when mediating af_unix in usernsGabriel Totev
Avoid unshifted ouids for socket file operations as observed when using AppArmor profiles in unprivileged containers with LXD or Incus. For example, root inside container and uid 1000000 outside, with `owner /root/sock rw,` profile entry for nc: /root$ nc -lkU sock & nc -U sock ==> dmesg apparmor="DENIED" operation="connect" class="file" namespace="root//lxd-podia_<var-snap-lxd-common-lxd>" profile="sockit" name="/root/sock" pid=3924 comm="nc" requested_mask="wr" denied_mask="wr" fsuid=1000000 ouid=0 [<== should be 1000000] Fix by performing uid mapping as per common_perm_cond() in lsm.c Signed-off-by: Gabriel Totev <gabriel.totev@zetier.com> Fixes: c05e705812d1 ("apparmor: add fine grained af_unix mediation") Signed-off-by: John Johansen <john.johansen@canonical.com>
2025-07-20apparmor: make sure unix socket labeling is correctly updated.John Johansen
When a unix socket is passed into a different confinement domain make sure its cached mediation labeling is updated to correctly reflect which domains are using the socket. Fixes: c05e705812d1 ("apparmor: add fine grained af_unix mediation") Signed-off-by: John Johansen <john.johansen@canonical.com>
2025-07-15apparmor: fix regression in fs based unix sockets when using old abiJohn Johansen
Policy loaded using abi 7 socket mediation was not being applied correctly in all cases. In some cases with fs based unix sockets a subset of permissions where allowed when they should have been denied. This was happening because the check for if the socket was an fs based unix socket came before the abi check. But the abi check is where the correct path is selected, so having the fs unix socket check occur early would cause the wrong code path to be used. Fix this by pushing the fs unix to be done after the abi check. Fixes: dcd7a559411e ("apparmor: gate make fine grained unix mediation behind v9 abi") Signed-off-by: John Johansen <john.johansen@canonical.com>
2025-07-15apparmor: fix af_unix auditing to include all address informationJohn Johansen
The auditing of addresses currently doesn't include the source address and mixes source and foreign/peer under the same audit name. Fix this so source is always addr, and the foreign/peer is peer_addr. Fixes: c05e705812d1 ("apparmor: add fine grained af_unix mediation") Signed-off-by: John Johansen <john.johansen@canonical.com>
2025-07-15apparmor: Remove use of the double lockJohn Johansen
The use of the double lock is not necessary and problematic. Instead pull the bits that need locks into their own sections and grab the needed references. Fixes: c05e705812d1 ("apparmor: add fine grained af_unix mediation") Signed-off-by: John Johansen <john.johansen@canonical.com>
2025-01-18apparmor: gate make fine grained unix mediation behind v9 abiJohn Johansen
Fine grained unix mediation in Ubuntu used ABI v7, and policy using this has propogated onto systems where fine grained unix mediation was not supported. The userspace policy compiler supports downgrading policy so the policy could be shared without changes. Unfortunately this had the side effect that policy was not updated for the none Ubuntu systems and enabling fine grained unix mediation on those systems means that a new kernel can break a system with existing policy that worked with the previous kernel. With fine grained af_unix mediation this regression can easily break the system causing boot to fail, as it affect unix socket files, non-file based unix sockets, and dbus communication. To aoid this regression move fine grained af_unix mediation behind a new abi. This means that the system's userspace and policy must be updated to support the new policy before it takes affect and dropping a new kernel on existing system will not result in a regression. The abi bump is done in such a way as existing policy can be activated on the system by changing the policy abi declaration and existing unix policy rules will apply. Policy then only needs to be incrementally updated, can even be backported to existing Ubuntu policy. Signed-off-by: John Johansen <john.johansen@canonical.com>
2025-01-18apparmor: add fine grained af_unix mediationJohn Johansen
Extend af_unix mediation to support fine grained controls based on the type (abstract, anonymous, fs), the address, and the labeling on the socket. This allows for using socket addresses to label and the socket and control which subjects can communicate. The unix rule format follows standard apparmor rules except that fs based unix sockets can be mediated by existing file rules. None fs unix sockets can be mediated by a unix socket rule. Where The address of an abstract unix domain socket begins with the @ character, similar to how they are reported (as paths) by netstat -x. The address then follows and may contain pattern matching and any characters including the null character. In apparmor null characters must be specified by using an escape sequence \000 or \x00. The pattern matching is the same as is used by file path matching so * will not match / even though it has no special meaning with in an abstract socket name. Eg. allow unix addr=@*, Autobound unix domain sockets have a unix sun_path assigned to them by the kernel, as such specifying a policy based address is not possible. The autobinding of sockets can be controlled by specifying the special auto keyword. Eg. allow unix addr=auto, To indicate that the rule only applies to auto binding of unix domain sockets. It is important to note this only applies to the bind permission as once the socket is bound to an address it is indistinguishable from a socket that have an addr bound with a specified name. When the auto keyword is used with other permissions or as part of a peer addr it will be replaced with a pattern that can match an autobound socket. Eg. For some kernels allow unix rw addr=auto, It is important to note, this pattern may match abstract sockets that were not autobound but have an addr that fits what is generated by the kernel when autobinding a socket. Anonymous unix domain sockets have no sun_path associated with the socket address, however it can be specified with the special none keyword to indicate the rule only applies to anonymous unix domain sockets. Eg. allow unix addr=none, If the address component of a rule is not specified then the rule applies to autobind, abstract and anonymous sockets. The label on the socket can be compared using the standard label= rule conditional. Eg. allow unix addr=@foo peer=(label=bar), see man apparmor.d for full syntax description. Signed-off-by: John Johansen <john.johansen@canonical.com>