From: Casey Schaufler <casey@schaufler-ca.com>
To: Paul Moore <paul@paul-moore.com>
Cc: john.johansen@canonical.com, selinux@vger.kernel.org,
linux-audit@redhat.com, casey.schaufler@intel.com,
Stephen Smalley <sds@tycho.nsa.gov>
Subject: Re: [PATCH v26 22/25] Audit: Add new record for multiple process LSM attributes
Date: Tue, 25 May 2021 10:28:37 -0700 [thread overview]
Message-ID: <39d6ac53-d965-de64-266f-d0fa3139e52f@schaufler-ca.com> (raw)
In-Reply-To: <CAHC9VhSdFVuZvThMsqWT-L9wcHevA-0yAX+kxqXN0iMmqRc10g@mail.gmail.com>
On 5/21/2021 1:19 PM, Paul Moore wrote:
<snip> and trim the CC list.
> Okay, we've got a disconnect here regarding "audit contexts" and
> "local contexts", skip down below where I attempt to explain things a
> little more but basically if there is a place that uses this pattern:
>
> audit_log_start(audit_context(), ...);
This pattern isn't helpful. audit_context() returns NULL in about 1 of 4 calls.
All of these callers of audit_context() get a NULL result some of the time.
getname_kernel
debugfs_create_dir
tracefs_create_file
vfs_fchown
do_settimeofday64
bprm_execve
ksys_mmap_pgoff
move_addr_to_kernel
__do_pipe_flags
__do_sys_capset
syscall_trace_enter
cap_bprm_creds_from_file
load_module
__x64_sys_fsetxattr
bpf_prog_load
audit_signal_info_syscall
sel_write_enforce
common_lsm_audit
audit_set_loginuid
__dev_set_promiscuity
ipcperms
devpts_pty_new
> ... you don't need, or want, a "local context". You might need a
> local context if you see the following pattern:
>
> audit_log_start(NULL, ...);
>
> The "local context" idea is a hack and should be avoided whenever
> possible; if you have an existing audit context from a syscall, or
> something else, you *really* should use it ... or have a *really* good
> explanation as to why you can not.
Almost all audit events want to record the subject context by calling
audit_log_task_context(). If multiple contexts need to be recorded
there has to be a separate record, which means there has to be an
audit context. The only case where an audit context is reliably available
is in syscalls. Hence, a "local context" for many of the cases where the
first argument to audit_log_start() would otherwise be NULL, either
explicitly or because audit_context() returns NULL.
Is there some other way to synchronize the "timestamp" without use of
an audit context? My understanding is that this is the primary purpose
of the audit context.
--
Linux-audit mailing list
Linux-audit@redhat.com
https://listman.redhat.com/mailman/listinfo/linux-audit
next prev parent reply other threads:[~2021-05-25 17:29 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210513200807.15910-1-casey.ref@schaufler-ca.com>
2021-05-13 20:07 ` [PATCH v26 00/25] LSM: Module stacking for AppArmor Casey Schaufler
2021-05-13 20:07 ` [PATCH v26 01/25] LSM: Infrastructure management of the sock security Casey Schaufler
2021-05-13 20:07 ` [PATCH v26 02/25] LSM: Add the lsmblob data structure Casey Schaufler
2021-05-22 8:39 ` Mickaël Salaün
2021-05-25 23:52 ` Casey Schaufler
2021-05-26 9:53 ` Mickaël Salaün
2021-05-13 20:07 ` [PATCH v26 03/25] LSM: provide lsm name and id slot mappings Casey Schaufler
2021-05-14 19:00 ` Kees Cook
2021-05-21 20:18 ` Paul Moore
2021-05-13 20:07 ` [PATCH v26 04/25] IMA: avoid label collisions with stacked LSMs Casey Schaufler
2021-05-14 19:00 ` Kees Cook
2021-05-13 20:07 ` [PATCH v26 05/25] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
2021-05-13 20:07 ` [PATCH v26 06/25] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
2021-05-13 20:07 ` [PATCH v26 07/25] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
2021-05-14 19:03 ` Kees Cook
2021-05-21 20:18 ` Paul Moore
2021-05-13 20:07 ` [PATCH v26 08/25] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
2021-05-14 19:05 ` Kees Cook
2021-05-21 20:18 ` Paul Moore
2021-05-13 20:07 ` [PATCH v26 09/25] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler
2021-05-13 20:07 ` [PATCH v26 10/25] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
2021-05-13 20:07 ` [PATCH v26 11/25] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
2021-05-13 20:07 ` [PATCH v26 12/25] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
2021-05-13 20:07 ` [PATCH v26 13/25] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
2021-05-13 20:07 ` [PATCH v26 14/25] LSM: Specify which LSM to display Casey Schaufler
2021-05-14 19:23 ` Kees Cook
2021-05-17 19:52 ` Casey Schaufler
2021-05-21 20:19 ` Paul Moore
2021-05-13 20:07 ` [PATCH v26 15/25] LSM: Ensure the correct LSM context releaser Casey Schaufler
2021-05-21 20:19 ` Paul Moore
2021-05-13 20:07 ` [PATCH v26 16/25] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2021-05-13 20:07 ` [PATCH v26 17/25] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
2021-05-14 19:24 ` Kees Cook
2021-05-13 20:08 ` [PATCH v26 18/25] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
2021-05-21 20:19 ` Paul Moore
2021-05-13 20:08 ` [PATCH v26 19/25] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
2021-05-13 20:08 ` [PATCH v26 20/25] LSM: Verify LSM display sanity in binder Casey Schaufler
2021-05-13 20:08 ` [PATCH v26 21/25] audit: add support for non-syscall auxiliary records Casey Schaufler
2021-05-21 20:19 ` Paul Moore
2021-05-13 20:08 ` [PATCH v26 22/25] Audit: Add new record for multiple process LSM attributes Casey Schaufler
2021-05-21 20:19 ` Paul Moore
2021-05-21 21:26 ` Richard Guy Briggs
2021-05-21 22:05 ` Casey Schaufler
2021-05-22 2:20 ` Paul Moore
2021-05-22 12:58 ` Richard Guy Briggs
2021-05-23 2:00 ` Steve Grubb
2021-05-24 15:53 ` Casey Schaufler
2021-05-24 16:06 ` Steve Grubb
2021-05-25 16:26 ` Casey Schaufler
2021-05-25 17:28 ` Casey Schaufler [this message]
2021-05-25 18:23 ` Richard Guy Briggs
2021-05-25 19:06 ` Casey Schaufler
2021-05-25 20:08 ` Richard Guy Briggs
2021-05-25 22:46 ` Casey Schaufler
2021-05-13 20:08 ` [PATCH v26 23/25] Audit: Add a new record for multiple object " Casey Schaufler
2021-05-13 20:08 ` [PATCH v26 24/25] LSM: Add /proc attr entry for full LSM context Casey Schaufler
2021-05-13 20:08 ` [PATCH v26 25/25] AppArmor: Remove the exclusive flag Casey Schaufler
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