linux-stable.git/kernel/auditfilter.c, branch v4.19.136

audit: fix a net reference leak in audit_list_rules_send()

2020-06-22T07:05:13+00:00

[ Upstream commit 3054d06719079388a543de6adb812638675ad8f5 ]

If audit_list_rules_send() fails when trying to create a new thread
to send the rules it also fails to cleanup properly, leaking a
reference to a net structure.  This patch fixes the error patch and
renames audit_send_list() to audit_send_list_thread() to better
match its cousin, audit_send_reply_thread().

Reported-by: teroincn@gmail.com
Reviewed-by: Richard Guy Briggs 
Signed-off-by: Paul Moore 
Signed-off-by: Sasha Levin

audit: fix error handling in audit_data_to_entry()

2020-03-05T15:42:17+00:00

commit 2ad3e17ebf94b7b7f3f64c050ff168f9915345eb upstream.

Commit 219ca39427bf ("audit: use union for audit_field values since
they are mutually exclusive") combined a number of separate fields in
the audit_field struct into a single union.  Generally this worked
just fine because they are generally mutually exclusive.
Unfortunately in audit_data_to_entry() the overlap can be a problem
when a specific error case is triggered that causes the error path
code to attempt to cleanup an audit_field struct and the cleanup
involves attempting to free a stored LSM string (the lsm_str field).
Currently the code always has a non-NULL value in the
audit_field.lsm_str field as the top of the for-loop transfers a
value into audit_field.val (both .lsm_str and .val are part of the
same union); if audit_data_to_entry() fails and the audit_field
struct is specified to contain a LSM string, but the
audit_field.lsm_str has not yet been properly set, the error handling
code will attempt to free the bogus audit_field.lsm_str value that
was set with audit_field.val at the top of the for-loop.

This patch corrects this by ensuring that the audit_field.val is only
set when needed (it is cleared when the audit_field struct is
allocated with kcalloc()).  It also corrects a few other issues to
ensure that in case of error the proper error code is returned.

Cc: stable@vger.kernel.org
Fixes: 219ca39427bf ("audit: use union for audit_field values since they are mutually exclusive")
Reported-by: syzbot+1f4d90ead370d72e450b@syzkaller.appspotmail.com
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

audit: fix a memory leak bug

2019-05-31T13:46:17+00:00

[ Upstream commit 70c4cf17e445264453bc5323db3e50aa0ac9e81f ]

In audit_rule_change(), audit_data_to_entry() is firstly invoked to
translate the payload data to the kernel's rule representation. In
audit_data_to_entry(), depending on the audit field type, an audit tree may
be created in audit_make_tree(), which eventually invokes kmalloc() to
allocate the tree.  Since this tree is a temporary tree, it will be then
freed in the following execution, e.g., audit_add_rule() if the message
type is AUDIT_ADD_RULE or audit_del_rule() if the message type is
AUDIT_DEL_RULE. However, if the message type is neither AUDIT_ADD_RULE nor
AUDIT_DEL_RULE, i.e., the default case of the switch statement, this
temporary tree is not freed.

To fix this issue, only allocate the tree when the type is AUDIT_ADD_RULE
or AUDIT_DEL_RULE.

Signed-off-by: Wenwen Wang 
Reviewed-by: Richard Guy Briggs 
Signed-off-by: Paul Moore 
Signed-off-by: Sasha Levin

audit: rename FILTER_TYPE to FILTER_EXCLUDE

2018-06-19T14:39:54+00:00

The AUDIT_FILTER_TYPE name is vague and misleading due to not describing
where or when the filter is applied and obsolete due to its available
filter fields having been expanded.

Userspace has already renamed it from AUDIT_FILTER_TYPE to
AUDIT_FILTER_EXCLUDE without checking if it already exists.  The
userspace maintainer assures that as long as it is set to the same value
it will not be a problem since the userspace code does not treat
compiler warnings as errors.  If this policy changes then checks if it
already exists can be added at the same time.

See: https://github.com/linux-audit/audit-kernel/issues/89

Signed-off-by: Richard Guy Briggs 
Signed-off-by: Paul Moore

audit: allow other filter list types for AUDIT_EXE

2018-06-19T13:33:42+00:00

This patch removes the restriction of the AUDIT_EXE field to only
SYSCALL filter and teaches audit_filter to recognize this field.

This makes it possible to write rule lists such as:

    auditctl -a exit,always [some general rule]
    # Filter out events with executable name /bin/exe1 or /bin/exe2:
    auditctl -a exclude,always -F exe=/bin/exe1
    auditctl -a exclude,always -F exe=/bin/exe2

See: https://github.com/linux-audit/audit-kernel/issues/54

Signed-off-by: Ondrej Mosnacek 
Reviewed-by: Richard Guy Briggs 
Signed-off-by: Paul Moore

audit: use existing session info function

2018-05-18T19:47:54+00:00

Use the existing audit_log_session_info() function rather than
hardcoding its functionality.

Signed-off-by: Richard Guy Briggs 
Signed-off-by: Paul Moore

audit: allow not equal op for audit by executable

2018-04-24T15:18:10+00:00

Current implementation of auditing by executable name only implements
the 'equal' operator. This patch extends it to also support the 'not
equal' operator.

See: https://github.com/linux-audit/audit-kernel/issues/53

Signed-off-by: Ondrej Mosnacek 
Reviewed-by: Richard Guy Briggs 
Signed-off-by: Paul Moore

audit: deprecate the AUDIT_FILTER_ENTRY filter

2018-02-15T19:36:29+00:00

The audit entry filter has been long deprecated with userspace support
finally removed in audit-v2.6.7 and plans to remove kernel support have
existed since kernel-v2.6.31.
Remove it.

Since removing the audit entry filter, test for early return before
setting up any context state.

Passes audit-testsuite.

See: https://github.com/linux-audit/audit-kernel/issues/6

Signed-off-by: Richard Guy Briggs 
Signed-off-by: Paul Moore

audit: session ID should not set arch quick field pointer

2018-02-14T21:34:22+00:00

A bug was introduced in 8fae47705685fcaa75a1fe4c8c3e18300a702979
("audit: add support for session ID user filter")
See: https://github.com/linux-audit/audit-kernel/issues/4

When setting a session ID filter, the session ID filter field overwrote
the quick pointer reference to the arch field, potentially causing the
arch field to be misinterpreted.

Passes audit-testsuite.

Signed-off-by: Richard Guy Briggs 
Signed-off-by: Paul Moore

audit: filter PATH records keyed on filesystem magic

2017-11-10T21:08:56+00:00

Tracefs or debugfs were causing hundreds to thousands of PATH records to
be associated with the init_module and finit_module SYSCALL records on a
few modules when the following rule was in place for startup:
	-a always,exit -F arch=x86_64 -S init_module -F key=mod-load

Provide a method to ignore these large number of PATH records from
overwhelming the logs if they are not of interest.  Introduce a new
filter list "AUDIT_FILTER_FS", with a new field type AUDIT_FSTYPE,
which keys off the filesystem 4-octet hexadecimal magic identifier to
filter specific filesystem PATH records.

An example rule would look like:
	-a never,filesystem -F fstype=0x74726163 -F key=ignore_tracefs
	-a never,filesystem -F fstype=0x64626720 -F key=ignore_debugfs

Arguably the better way to address this issue is to disable tracefs and
debugfs on boot from production systems.

See: https://github.com/linux-audit/audit-kernel/issues/16
See: https://github.com/linux-audit/audit-userspace/issues/8
Test case: https://github.com/linux-audit/audit-testsuite/issues/42

Signed-off-by: Richard Guy Briggs 
[PM: fixed the whitespace damage in kernel/auditsc.c]
Signed-off-by: Paul Moore