[PATCH v11 00/25] LSM: Module stacking for AppArmor

Sending the patches relevant to audit to the linux-audit list. This patchset provides the changes required for the AppArmor security module to stack safely with any other. v11: Rebase to 5.4-rc6 Incorporate feedback from v10 - Disambiguate reading /proc/.../attr/display by restricting all use of the interface to the current process. - Fix a merge error in AppArmor's display attribute check v10: Ask the security modules if the display can be changed. v9: There is no version 9 v8: Incorporate feedback from v7 - Minor clean-up in display value management - refactor "compound" context creation to use a common append_ctx() function. v7: Incorporate feedback from v6 - Make setting the display a privileged operation. The availability of compound contexts reduces the need for setting the display. v6: Incorporate feedback from v5 - Add subj_<lsm>= and obj_<lsm>= fields to audit records - Add /proc/.../attr/context to get the full context in lsmname\0value\0... format as suggested by Simon McVittie - Add SO_PEERCONTEXT for getsockopt() to get the full context in the same format, also suggested by Simon McVittie. - Add /sys/kernel/security/lsm_display_default to provide the display default value. v5: Incorporate feedback from v4 - Initialize the lsmcontext in security_secid_to_secctx() - Clear the lsmcontext in all security_release_secctx() cases - Don't use the "display" on strictly internal context interfaces. - The SELinux binder hooks check for cases where the context "display" isn't compatible with SELinux. v4: Incorporate feedback from v3 - Mark new lsm_<blob>_alloc functions static - Replace the lsm and slot fields of the security_hook_list with a pointer to a LSM allocated lsm_id structure. The LSM identifies if it needs a slot explicitly. Use the lsm_id rather than make security_add_hooks return the slot value. - Validate slot values used in security.c - Reworked the "display" process attribute handling so that it works right and doesn't use goofy list processing. - fix display value check in dentry_init_security - Replace audit_log of secids with '?' instead of deleting the audit log v3: Incorporate feedback from v2 - Make lsmblob parameter and variable names more meaningful, changing "le" and "l" to "blob". - Improve consistency of constant naming. - Do more sanity checking during LSM initialization. - Be a bit clearer about what is temporary scaffolding. - Rather than clutter security_getpeersec_dgram with otherwise unnecessary checks remove the apparmor stub, which does nothing useful. Patche 0001 moves management of the sock security blob from the individual modules to the infrastructure. Patches 0002-0012 replace system use of a "secid" with a structure "lsmblob" containing information from the security modules to be held and reused later. At this point lsmblob contains an array of u32 secids, one "slot" for each of the security modules compiled into the kernel that used secids. A "slot" is allocated when a security module requests one. The infrastructure is changed to use the slot number to pass the correct secid to or from the security module hooks. It is important that the lsmblob be a fixed size entity that does not have to be allocated. Several of the places where it is used would have performance and/or locking issues with dynamic allocation. Patch 0013 provides a mechanism for a process to identify which security module's hooks should be used when displaying or converting a security context string. A new interface /proc/self/attr/display contains the name of the security module to show. Reading from this file will present the name of the module, while writing to it will set the value. Only names of active security modules are accepted. Internally, the name is translated to the appropriate "slot" number for the module which is then stored in the task security blob. Setting the display requires that all modules using the /proc interfaces allow the transition. The "display" of other processess can be neither read nor written. All suggested cases for reading the display of a different process have race conditions. Patch 0014 Starts the process of changing how a security context is represented. Since it is possible for a security context to have been generated by more than one security module it is now necessary to note which module created a security context so that the correct "release" hook can be called. There are several places where the module that created a security context cannot be inferred. This is achieved by introducing a "lsmcontext" structure which contains the context string, its length and the "slot" number of the security module that created it. The security_release_secctx() interface is changed, replacing the (string,len) pointer pair with a lsmcontext pointer. Patches 0015-0017 convert the security interfaces from (string,len) pointer pairs to a lsmcontext pointer. The slot number identifying the creating module is added by the infrastructure. Where the security context is stored for extended periods the data type is changed. The Netlabel code is converted to save lsmblob structures instead of secids in Patches 0018-0019. Patch 0020 adds checks to the binder hooks which verify that if both ends of a transaction use the same "display". Patches 0021-0022 add addition data to the audit records to identify the LSM specific data for all active modules. Patches 0023-0024 add new interfaces for getting the compound security contexts. Finally, with all interference on the AppArmor hooks removed, Patch 0025 removes the exclusive bit from AppArmor. An unnecessary stub hook was also removed. The Ubuntu project is using an earlier version of this patchset in their distribution to enable stacking for containers. Performance measurements to date have the change within the "noise". The sockperf and dbench results are on the order of 0.2% to 0.8% difference, with better performance being as common as worse. The benchmarks were run with AppArmor and Smack on Ubuntu. https://github.com/cschaufler/lsm-stacking.git#stack-5.4-rc6-v11-apparmor Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- arch/alpha/include/uapi/asm/socket.h | 1 + arch/mips/include/uapi/asm/socket.h | 1 + arch/parisc/include/uapi/asm/socket.h | 1 + arch/sparc/include/uapi/asm/socket.h | 1 + drivers/android/binder.c | 26 +- fs/ceph/xattr.c | 6 +- fs/nfs/nfs4proc.c | 22 +- fs/nfsd/nfs4xdr.c | 20 +- fs/proc/base.c | 2 + include/linux/audit.h | 1 + include/linux/cred.h | 3 +- include/linux/lsm_hooks.h | 37 +- include/linux/security.h | 175 ++++++++-- include/net/af_unix.h | 2 +- include/net/netlabel.h | 8 +- include/net/scm.h | 15 +- include/uapi/asm-generic/socket.h | 1 + kernel/audit.c | 72 +++- kernel/audit.h | 9 +- kernel/audit_fsnotify.c | 1 + kernel/auditfilter.c | 10 +- kernel/auditsc.c | 127 ++++--- kernel/cred.c | 12 +- net/core/sock.c | 7 +- net/ipv4/cipso_ipv4.c | 6 +- net/ipv4/ip_sockglue.c | 12 +- net/netfilter/nf_conntrack_netlink.c | 20 +- net/netfilter/nf_conntrack_standalone.c | 11 +- net/netfilter/nfnetlink_queue.c | 26 +- net/netfilter/nft_meta.c | 13 +- net/netfilter/xt_SECMARK.c | 5 +- net/netlabel/netlabel_kapi.c | 6 +- net/netlabel/netlabel_unlabeled.c | 97 +++--- net/netlabel/netlabel_unlabeled.h | 2 +- net/netlabel/netlabel_user.c | 13 +- net/netlabel/netlabel_user.h | 6 +- net/unix/af_unix.c | 6 +- net/xfrm/xfrm_policy.c | 2 + net/xfrm/xfrm_state.c | 2 + security/apparmor/include/apparmor.h | 3 +- security/apparmor/include/net.h | 6 +- security/apparmor/lsm.c | 117 +++---- security/commoncap.c | 7 +- security/integrity/ima/ima.h | 15 +- security/integrity/ima/ima_api.c | 11 +- security/integrity/ima/ima_appraise.c | 6 +- security/integrity/ima/ima_main.c | 49 +-- security/integrity/ima/ima_policy.c | 19 +- security/integrity/integrity_audit.c | 1 + security/loadpin/loadpin.c | 8 +- security/safesetid/lsm.c | 8 +- security/security.c | 593 +++++++++++++++++++++++++++++--- security/selinux/hooks.c | 109 +++--- security/selinux/include/classmap.h | 2 +- security/selinux/include/objsec.h | 5 + security/selinux/include/security.h | 1 + security/selinux/netlabel.c | 25 +- security/selinux/ss/services.c | 4 +- security/smack/smack.h | 6 + security/smack/smack_lsm.c | 124 ++++--- security/smack/smack_netfilter.c | 8 +- security/smack/smackfs.c | 10 +- security/tomoyo/tomoyo.c | 8 +- security/yama/yama_lsm.c | 7 +- 64 files changed, 1376 insertions(+), 563 deletions(-)