[PATCH v24 00/25] LSM: Module stacking for AppArmor
by Casey Schaufler
This patchset provides the changes required for
the AppArmor security module to stack safely with any other.
v24: Rebase to 5.11-rc1
Incorporate feedback from v23
- Address the IMA team's concerns about "label collisions".
A label collision occurs when there is ambiguity about
which of multiple LSMs is being targeted in the definition
of an integrity check rule. A system with Smack and
AppArmor would be unable to distinguish which LSM is
important to an integrity rule referrencing the label
"unconfined" as that label is meaningful to both.
Provide a boot option to specify which LSM will be used in
IMA rules when multiple LSMs are present. (patch 04)
Pull LSM "slot" identification from later audit patches in
in support of this (patch 03).
- Pick up a few audit events that need to include supplimental
subject context records that had been missed in the
previous version.
v23: Rebase to 5.10-rc4
Incorporate feedback from v22
- Change /proc/*/attr/display to /proc/*/attr/interface_lsm to
make the purpose clearer. (patch 0012)
- Include ABI documentation. (patch 0012, 0022)
- Introduce LSM documentation updates with the patches where
the interfaces are added rather than at the end. (patch 0012, 0022)
Include more maintainers and mail lists in To: and Cc: directives.
v22: Rebase to 5.10-rc1
v21: Rebase to 5.9-rc4
Incorporate feedback from v20
- Further revert UDS SO_PEERSEC to use scaffolding around
the interfaces that use lsmblobs and store only a single
secid. The possibility of multiple security modules
requiring data here is still a future problem.
- Incorporate Richard Guy Briggs' non-syscall auxiliary
records patch (patch 0019-0021) in place of my "supplimental"
records implementation. [I'm not sure I've given proper
attestation. I will correct as appropriate]
v20: Rebase to 5.9-rc1
Change the BPF security module to use the lsmblob data. (patch 0002)
Repair length logic in subject label processing (patch 0015)
Handle -EINVAL from the empty BPF setprocattr hook (patch 0020)
Correct length processing in append_ctx() (patch 0022)
v19: Rebase to 5.8-rc6
Incorporate feedback from v18
- Revert UDS SO_PEERSEC implementation to use lsmblobs
directly, rather than allocating as needed. The correct
treatment of out-of-memory conditions in the later case
is difficult to define. (patch 0005)
- Use a size_t in append_ctx() (patch 0021)
- Fix a memory leak when creating compound contexts. (patch 0021)
Fix build error when CONFIG_SECURITY isn't set (patch 0013)
Fix build error when CONFIG_SECURITY isn't set (patch 0020)
Fix build error when CONFIG_SECURITY isn't set (patch 0021)
v18: Rebase to 5.8-rc3
Incorporate feedback from v17
- Null pointer checking in UDS (patch 0005)
Match changes in IMA code (patch 0012)
Fix the behavior of LSM context supplimental audit
records so that there's always exactly one when it's
appropriate for there to be one. This is a substantial
change that requires extention of the audit_context beyond
syscall events. (patch 0020)
v17: Rebase to 5.7-rc4
v16: Rebase to 5.6
Incorporate feedback from v15 - Thanks Stephen, Mimi and Paul
- Generally improve commit messages WRT scaffolding
- Comment ima_lsm_isset() (patch 0002)
- Some question may remain on IMA warning (patch 0002)
- Mark lsm_slot as __lsm_ro_after_init not __init_data (patch 0002)
- Change name of lsmblob variable in ima_match_rules() (patch 0003)
- Instead of putting a struct lsmblob into the unix_skb_parms
structure put a pointer to an allocated instance. There is
currently only space for 5 u32's in unix_skb_parms and it is
likely to get even tighter. Fortunately, the lifecycle
management of the allocated lsmblob is simple. (patch 0005)
- Dropped Acks due to the above change (patch 0005)
- Improved commentary on secmark labeling scaffolding. (patch 0006)
- Reduced secmark related labeling scaffolding. (patch 0006)
- Replace use of the zeroth entry of an lsmblob in scaffolding
with a function lsmblob_value() to hopefully make it less
obscure. (patch 0006)
- Convert security_secmark_relabel_packet to use lsmblob as
this reduces much of the most contentious scaffolding. (patch 0006)
- Dropped Acks due to the above change (patch 0006)
- Added BUILD_BUG_ON() for CIPSO tag 6. (patch 0018)
- Reworked audit subject information. Instead of adding fields in
the middle of existing records add a new record to the event. When
a separate record is required use subj="?". (patch 0020)
- Dropped Acks due to the above change (patch 0020)
- Reworked audit object information. Instead of adding fields in
the middle of existing records add a new record to the event. When
a separate record is required use obj="?". (patch 0021)
- Dropped Acks due to the above change (patch 0021)
- Enhanced documentation (patch 0022)
- Removed unnecessary error code check in security_getprocattr()
(patch 0021)
v15: Rebase to 5.6-rc1
- Revise IMA data use (patch 0002)
Incorporate feedback from v14
- Fix lockdown module registration naming (patch 0002)
- Revise how /proc/self/attr/context is gathered. (patch 0022)
- Revise access modes on /proc/self/attr/context. (patch 0022)
- Revise documentation on LSM external interfaces. (patch 0022)
v14: Rebase to 5.5-rc5
Incorporate feedback from v13
- Use an array of audit rules (patch 0002)
- Significant change, removed Acks (patch 0002)
- Remove unneeded include (patch 0013)
- Use context.len correctly (patch 0015)
- Reorder code to be more sensible (patch 0016)
- Drop SO_PEERCONTEXT as it's not needed yet (patch 0023)
v13: Rebase to 5.5-rc2
Incorporate feedback from v12
- Print lsmblob size with %z (Patch 0002)
- Convert lockdown LSM initialization. (Patch 0002)
- Restore error check in nft_secmark_compute_secid (Patch 0006)
- Correct blob scaffolding in ima_must_appraise() (Patch 0009)
- Make security_setprocattr() clearer (Patch 0013)
- Use lsm_task_display more widely (Patch 0013)
- Use passed size in lsmcontext_init() (Patch 0014)
- Don't add a smack_release_secctx() hook (Patch 0014)
- Don't print warning in security_release_secctx() (Patch 0014)
- Don't duplicate the label in nfs4_label_init_security() (Patch 0016)
- Remove reviewed-by as code has significant change (Patch 0016)
- Send the entire lsmblob for Tag 6 (Patch 0019)
- Fix description of socket_getpeersec_stream parameters (Patch 0023)
- Retain LSMBLOB_FIRST. What was I thinking? (Patch 0023)
- Add compound context to LSM documentation (Patch 0023)
v12: Rebase to 5.5-rc1
Fixed a couple of incorrect contractions in the text.
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.
Patch 01 moves management of the sock security blob
from the individual modules to the infrastructure.
Patches 02-03 introduce a structure "lsmblob" that will gradually
replace the "secid" as a shorthand for security module information.
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.
Patch 04 provides mechanism for the IMA subsystem to identify
explicitly which LSM is subject to IMA policy. This includes
a boot option for specifying the default and an additional option
in IMA rules "lsm=".
Patches 05-13 change LSM interfaces to use the lsmblob instead
of secids. 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 14 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/interface_lsm 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 interface LSM of other processess
can be neither read nor written. All suggested cases for
reading the interface LSM of a different process have race
conditions.
Patch 15 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 16-18 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 Patch 19. This is not strictly
necessary as there can only be one security module that
uses Netlabel at this point. Using a lsmblob is much
cleaner, as the interfaces that use the data have all
been converted.
Patch 20 adds checks to the binder hooks which verify
that both ends of a transaction use the same interface LSM.
Patches 21-23 add addition audit records for subject and
object LSM data when there are multiple security modules
with such data. The AUDIT_MAC_TASK_CONTEXTS record is used
in conjuction with a "subj=?" field to identify the subject
data. The AUDIT_MAC_OBJ_CONTEXTS record is used in conjuction
with a "obj=?" field to identify the object data. The
AUDIT_MAC_TASK_CONTEXTS record identifies the security module
with the data: "subj_selinux=xyz_t subj_apparmor=abc". The
AUDIT_MAC_OBJ_CONTEXTS record identifies the security module
with the data: "obj_selinux=xyz_t obj_apparmor=abc". While
AUDIT_MAC_TASK_CONTEXTS records will always contain an entry
for each possible security modules, AUDIT_MAC_OBJ_CONTEXTS
records will only contain entries for security modules for
which the object in question has data.
An example of the MAC_TASK_CONTEXTS (1420) record is:
type=UNKNOWN[1420]
msg=audit(1600880931.832:113)
subj_apparmor==unconfined
subj_smack=_
An example of the MAC_OBJ_CONTEXTS (1421) record is:
type=UNKNOWN[1421]
msg=audit(1601152467.009:1050):
obj_selinux=unconfined_u:object_r:user_home_t:s0
Patch 24 adds a new interface for getting the compound security
contexts, /proc/self/attr/context. An example of the content
of this file is:
selinux\0one_u:one_r:one_t:s0-s0:c0.c1023\0apparmor\0unconfined\0
Finally, with all interference on the AppArmor hooks removed,
Patch 25 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-5.11-rc1-v24
Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com>
Casey Schaufler (25):
LSM: Infrastructure management of the sock security
LSM: Add the lsmblob data structure.
LSM: provide lsm name and id slot mappings
IMA: avoid label collisions with stacked LSMs
LSM: Use lsmblob in security_audit_rule_match
LSM: Use lsmblob in security_kernel_act_as
LSM: Use lsmblob in security_secctx_to_secid
LSM: Use lsmblob in security_secid_to_secctx
LSM: Use lsmblob in security_ipc_getsecid
LSM: Use lsmblob in security_task_getsecid
LSM: Use lsmblob in security_inode_getsecid
LSM: Use lsmblob in security_cred_getsecid
IMA: Change internal interfaces to use lsmblobs
LSM: Specify which LSM to display
LSM: Ensure the correct LSM context releaser
LSM: Use lsmcontext in security_secid_to_secctx
LSM: Use lsmcontext in security_inode_getsecctx
LSM: security_secid_to_secctx in netlink netfilter
NET: Store LSM netlabel data in a lsmblob
LSM: Verify LSM display sanity in binder
audit: add support for non-syscall auxiliary records
Audit: Add new record for multiple process LSM attributes
Audit: Add a new record for multiple object LSM attributes
LSM: Add /proc attr entry for full LSM context
AppArmor: Remove the exclusive flag
Documentation/ABI/testing/ima_policy | 8 +-
Documentation/ABI/testing/procfs-attr-context | 14 +
.../ABI/testing/procfs-attr-lsm_display | 22 +
Documentation/security/lsm.rst | 28 +
drivers/android/binder.c | 26 +-
fs/ceph/xattr.c | 6 +-
fs/nfs/nfs4proc.c | 8 +-
fs/nfsd/nfs4xdr.c | 20 +-
fs/proc/base.c | 2 +
include/linux/audit.h | 43 +-
include/linux/cred.h | 3 +-
include/linux/lsm_hooks.h | 36 +-
include/linux/security.h | 185 +++++-
include/net/netlabel.h | 11 +-
include/net/scm.h | 15 +-
include/net/xfrm.h | 13 +-
include/uapi/linux/audit.h | 2 +
kernel/audit.c | 175 ++++--
kernel/audit.h | 11 +-
kernel/auditfilter.c | 36 +-
kernel/auditsc.c | 191 +++---
kernel/cred.c | 12 +-
net/ipv4/cipso_ipv4.c | 26 +-
net/ipv4/ip_sockglue.c | 12 +-
net/netfilter/nf_conntrack_netlink.c | 24 +-
net/netfilter/nf_conntrack_standalone.c | 11 +-
net/netfilter/nfnetlink_queue.c | 38 +-
net/netfilter/nft_meta.c | 10 +-
net/netfilter/xt_SECMARK.c | 7 +-
net/netlabel/netlabel_domainhash.c | 4 +-
net/netlabel/netlabel_kapi.c | 6 +-
net/netlabel/netlabel_unlabeled.c | 106 ++--
net/netlabel/netlabel_unlabeled.h | 2 +-
net/netlabel/netlabel_user.c | 23 +-
net/netlabel/netlabel_user.h | 2 +-
net/xfrm/xfrm_policy.c | 10 +-
net/xfrm/xfrm_state.c | 20 +-
security/apparmor/include/apparmor.h | 3 +-
security/apparmor/include/net.h | 6 +-
security/apparmor/include/procattr.h | 2 +-
security/apparmor/lsm.c | 105 ++--
security/apparmor/procattr.c | 22 +-
security/bpf/hooks.c | 12 +-
security/commoncap.c | 7 +-
security/integrity/ima/ima.h | 15 +-
security/integrity/ima/ima_api.c | 17 +-
security/integrity/ima/ima_appraise.c | 6 +-
security/integrity/ima/ima_main.c | 54 +-
security/integrity/ima/ima_policy.c | 97 ++-
security/integrity/integrity_audit.c | 6 +-
security/loadpin/loadpin.c | 8 +-
security/lockdown/lockdown.c | 7 +-
security/safesetid/lsm.c | 8 +-
security/security.c | 561 ++++++++++++++++--
security/selinux/hooks.c | 99 ++--
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_access.c | 2 +-
security/smack/smack_lsm.c | 91 +--
security/smack/smack_netfilter.c | 8 +-
security/smack/smackfs.c | 13 +-
security/tomoyo/tomoyo.c | 8 +-
security/yama/yama_lsm.c | 7 +-
67 files changed, 1741 insertions(+), 634 deletions(-)
create mode 100644 Documentation/ABI/testing/procfs-attr-context
create mode 100644 Documentation/ABI/testing/procfs-attr-lsm_display
--
2.25.4
3 years, 8 months
[PATCH ghak124 v3] audit: log nftables configuration change events
by Richard Guy Briggs
iptables, ip6tables, arptables and ebtables table registration,
replacement and unregistration configuration events are logged for the
native (legacy) iptables setsockopt api, but not for the
nftables netlink api which is used by the nft-variant of iptables in
addition to nftables itself.
Add calls to log the configuration actions in the nftables netlink api.
This uses the same NETFILTER_CFG record format but overloads the table
field.
type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.878:162) : table=?:0;?:0 family=unspecified entries=2 op=nft_register_gen pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
...
type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.878:162) : table=firewalld:1;?:0 family=inet entries=0 op=nft_register_table pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
...
type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;filter_FORWARD:85 family=inet entries=8 op=nft_register_chain pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
...
type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;filter_FORWARD:85 family=inet entries=101 op=nft_register_rule pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
...
type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;__set0:87 family=inet entries=87 op=nft_register_setelem pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
...
type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;__set0:87 family=inet entries=0 op=nft_register_set pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
For further information please see issue
https://github.com/linux-audit/audit-kernel/issues/124
Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com>
---
Changelog:
v3:
- inline message type rather than table
v2:
- differentiate between xtables and nftables
- add set, setelem, obj, flowtable, gen
- use nentries field as appropriate per type
- overload the "tables" field with table handle and chain/set/flowtable
include/linux/audit.h | 18 ++++++++
kernel/auditsc.c | 24 ++++++++--
net/netfilter/nf_tables_api.c | 103 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 142 insertions(+), 3 deletions(-)
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 3fcd9ee49734..604ede630580 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -12,6 +12,7 @@
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <uapi/linux/audit.h>
+#include <uapi/linux/netfilter/nf_tables.h>
#define AUDIT_INO_UNSET ((unsigned long)-1)
#define AUDIT_DEV_UNSET ((dev_t)-1)
@@ -98,6 +99,23 @@ enum audit_nfcfgop {
AUDIT_XT_OP_REGISTER,
AUDIT_XT_OP_REPLACE,
AUDIT_XT_OP_UNREGISTER,
+ AUDIT_NFT_OP_TABLE_REGISTER,
+ AUDIT_NFT_OP_TABLE_UNREGISTER,
+ AUDIT_NFT_OP_CHAIN_REGISTER,
+ AUDIT_NFT_OP_CHAIN_UNREGISTER,
+ AUDIT_NFT_OP_RULE_REGISTER,
+ AUDIT_NFT_OP_RULE_UNREGISTER,
+ AUDIT_NFT_OP_SET_REGISTER,
+ AUDIT_NFT_OP_SET_UNREGISTER,
+ AUDIT_NFT_OP_SETELEM_REGISTER,
+ AUDIT_NFT_OP_SETELEM_UNREGISTER,
+ AUDIT_NFT_OP_GEN_REGISTER,
+ AUDIT_NFT_OP_OBJ_REGISTER,
+ AUDIT_NFT_OP_OBJ_UNREGISTER,
+ AUDIT_NFT_OP_OBJ_RESET,
+ AUDIT_NFT_OP_FLOWTABLE_REGISTER,
+ AUDIT_NFT_OP_FLOWTABLE_UNREGISTER,
+ AUDIT_NFT_OP_INVALID,
};
extern int is_audit_feature_set(int which);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 468a23390457..3a9100e95fda 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -75,6 +75,7 @@
#include <linux/uaccess.h>
#include <linux/fsnotify_backend.h>
#include <uapi/linux/limits.h>
+#include <uapi/linux/netfilter/nf_tables.h>
#include "audit.h"
@@ -136,9 +137,26 @@ struct audit_nfcfgop_tab {
};
static const struct audit_nfcfgop_tab audit_nfcfgs[] = {
- { AUDIT_XT_OP_REGISTER, "register" },
- { AUDIT_XT_OP_REPLACE, "replace" },
- { AUDIT_XT_OP_UNREGISTER, "unregister" },
+ { AUDIT_XT_OP_REGISTER, "xt_register" },
+ { AUDIT_XT_OP_REPLACE, "xt_replace" },
+ { AUDIT_XT_OP_UNREGISTER, "xt_unregister" },
+ { AUDIT_NFT_OP_TABLE_REGISTER, "nft_register_table" },
+ { AUDIT_NFT_OP_TABLE_UNREGISTER, "nft_unregister_table" },
+ { AUDIT_NFT_OP_CHAIN_REGISTER, "nft_register_chain" },
+ { AUDIT_NFT_OP_CHAIN_UNREGISTER, "nft_unregister_chain" },
+ { AUDIT_NFT_OP_RULE_REGISTER, "nft_register_rule" },
+ { AUDIT_NFT_OP_RULE_UNREGISTER, "nft_unregister_rule" },
+ { AUDIT_NFT_OP_SET_REGISTER, "nft_register_set" },
+ { AUDIT_NFT_OP_SET_UNREGISTER, "nft_unregister_set" },
+ { AUDIT_NFT_OP_SETELEM_REGISTER, "nft_register_setelem" },
+ { AUDIT_NFT_OP_SETELEM_UNREGISTER, "nft_unregister_setelem" },
+ { AUDIT_NFT_OP_GEN_REGISTER, "nft_register_gen" },
+ { AUDIT_NFT_OP_OBJ_REGISTER, "nft_register_obj" },
+ { AUDIT_NFT_OP_OBJ_UNREGISTER, "nft_unregister_obj" },
+ { AUDIT_NFT_OP_OBJ_RESET, "nft_reset_obj" },
+ { AUDIT_NFT_OP_FLOWTABLE_REGISTER, "nft_register_flowtable" },
+ { AUDIT_NFT_OP_FLOWTABLE_UNREGISTER, "nft_unregister_flowtable" },
+ { AUDIT_NFT_OP_INVALID, "nft_invalid" },
};
static int audit_match_perm(struct audit_context *ctx, int mask)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 3558e76e2733..b9e7440cc87d 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -12,6 +12,7 @@
#include <linux/netlink.h>
#include <linux/vmalloc.h>
#include <linux/rhashtable.h>
+#include <linux/audit.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nf_tables.h>
@@ -693,6 +694,16 @@ static void nf_tables_table_notify(const struct nft_ctx *ctx, int event)
{
struct sk_buff *skb;
int err;
+ char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0",
+ ctx->table->name, ctx->table->handle);
+
+ audit_log_nfcfg(buf,
+ ctx->family,
+ ctx->table->use,
+ event == NFT_MSG_NEWTABLE ?
+ AUDIT_NFT_OP_TABLE_REGISTER :
+ AUDIT_NFT_OP_TABLE_UNREGISTER);
+ kfree(buf);
if (!ctx->report &&
!nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
@@ -1428,6 +1439,17 @@ static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event)
{
struct sk_buff *skb;
int err;
+ char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu",
+ ctx->table->name, ctx->table->handle,
+ ctx->chain->name, ctx->chain->handle);
+
+ audit_log_nfcfg(buf,
+ ctx->family,
+ ctx->chain->use,
+ event == NFT_MSG_NEWCHAIN ?
+ AUDIT_NFT_OP_CHAIN_REGISTER :
+ AUDIT_NFT_OP_CHAIN_UNREGISTER);
+ kfree(buf);
if (!ctx->report &&
!nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
@@ -2691,6 +2713,17 @@ static void nf_tables_rule_notify(const struct nft_ctx *ctx,
{
struct sk_buff *skb;
int err;
+ char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu",
+ ctx->table->name, ctx->table->handle,
+ ctx->chain->name, ctx->chain->handle);
+
+ audit_log_nfcfg(buf,
+ ctx->family,
+ rule->handle,
+ event == NFT_MSG_NEWRULE ?
+ AUDIT_NFT_OP_RULE_REGISTER :
+ AUDIT_NFT_OP_RULE_UNREGISTER);
+ kfree(buf);
if (!ctx->report &&
!nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
@@ -3693,6 +3726,17 @@ static void nf_tables_set_notify(const struct nft_ctx *ctx,
struct sk_buff *skb;
u32 portid = ctx->portid;
int err;
+ char *buf = kasprintf(gfp_flags, "%s:%llu;%s:%llu",
+ ctx->table->name, ctx->table->handle,
+ set->name, set->handle);
+
+ audit_log_nfcfg(buf,
+ ctx->family,
+ set->field_count,
+ event == NFT_MSG_NEWSET ?
+ AUDIT_NFT_OP_SET_REGISTER :
+ AUDIT_NFT_OP_SET_UNREGISTER);
+ kfree(buf);
if (!ctx->report &&
!nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
@@ -4809,6 +4853,17 @@ static void nf_tables_setelem_notify(const struct nft_ctx *ctx,
u32 portid = ctx->portid;
struct sk_buff *skb;
int err;
+ char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu",
+ ctx->table->name, ctx->table->handle,
+ set->name, set->handle);
+
+ audit_log_nfcfg(buf,
+ ctx->family,
+ set->handle,
+ event == NFT_MSG_NEWSETELEM ?
+ AUDIT_NFT_OP_SETELEM_REGISTER :
+ AUDIT_NFT_OP_SETELEM_UNREGISTER);
+ kfree(buf);
if (!ctx->report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
return;
@@ -5890,6 +5945,19 @@ static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb)
obj->ops->type->type != filter->type)
goto cont;
+ if (reset) {
+ char *buf = kasprintf(GFP_KERNEL,
+ "%s:%llu;?:0",
+ table->name,
+ table->handle);
+
+ audit_log_nfcfg(buf,
+ family,
+ obj->handle,
+ AUDIT_NFT_OP_OBJ_RESET);
+ kfree(buf);
+ }
+
if (nf_tables_fill_obj_info(skb, net, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
NFT_MSG_NEWOBJ,
@@ -6000,6 +6068,17 @@ static int nf_tables_getobj(struct net *net, struct sock *nlsk,
if (NFNL_MSG_TYPE(nlh->nlmsg_type) == NFT_MSG_GETOBJ_RESET)
reset = true;
+ if (reset) {
+ char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0",
+ table->name, table->handle);
+
+ audit_log_nfcfg(buf,
+ family,
+ obj->handle,
+ AUDIT_NFT_OP_OBJ_RESET);
+ kfree(buf);
+ }
+
err = nf_tables_fill_obj_info(skb2, net, NETLINK_CB(skb).portid,
nlh->nlmsg_seq, NFT_MSG_NEWOBJ, 0,
family, table, obj, reset);
@@ -6075,6 +6154,16 @@ void nft_obj_notify(struct net *net, const struct nft_table *table,
{
struct sk_buff *skb;
int err;
+ char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0",
+ table->name, table->handle);
+
+ audit_log_nfcfg(buf,
+ family,
+ obj->handle,
+ event == NFT_MSG_NEWOBJ ?
+ AUDIT_NFT_OP_OBJ_REGISTER :
+ AUDIT_NFT_OP_OBJ_UNREGISTER);
+ kfree(buf);
if (!report &&
!nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
@@ -6701,6 +6790,17 @@ static void nf_tables_flowtable_notify(struct nft_ctx *ctx,
{
struct sk_buff *skb;
int err;
+ char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu",
+ flowtable->table->name, flowtable->table->handle,
+ flowtable->name, flowtable->handle);
+
+ audit_log_nfcfg(buf,
+ ctx->family,
+ flowtable->hooknum,
+ event == NFT_MSG_NEWFLOWTABLE ?
+ AUDIT_NFT_OP_FLOWTABLE_REGISTER :
+ AUDIT_NFT_OP_FLOWTABLE_UNREGISTER);
+ kfree(buf);
if (ctx->report &&
!nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
@@ -6822,6 +6922,9 @@ static void nf_tables_gen_notify(struct net *net, struct sk_buff *skb,
struct sk_buff *skb2;
int err;
+ audit_log_nfcfg("?:0;?:0", 0, net->nft.base_seq,
+ AUDIT_NFT_OP_GEN_REGISTER);
+
if (nlmsg_report(nlh) &&
!nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
return;
--
1.8.3.1
3 years, 8 months
[RFC,v3,1/1] audit: speed up syscall rule filtering
by yang.yang29＠zte.com.cn
From 85b3eccf7f12b091b78cc5ba8abfaf759cf0334e Mon Sep 17 00:00:00 2001
From: Yang Yang <yang.yang29(a)zte.com.cn>
Date: Sun, 24 Jan 2021 20:40:50 +0800
Subject: [PATCH] audit: speed up syscall rule filtering
audit_filter_syscall() traverses struct list_head audit_filter_list to find
out whether current syscall match one rule. This takes o(n), which is not
necessary, specially for user who add a very few syscall rules. On the other
hand, user may not much care about rule add/delete speed. So do o(n)
calculates when rule changes, and ease the burden of audit_filter_syscall().
Define audit_rule_syscall_mask[NR_syscalls], every element stands for
one syscall.audit_rule_syscall_mask[n] == 0 indicates no rule cares about
syscall n, so we can avoid unnecessary calling audit_filter_syscall().
audit_rule_syscall_mask[n] > 0 indicates at least one rule cares about
syscall n, then calls audit_filter_syscall(). Update
audit_rule_syscall_mask[n] when syscall rule changes.
Signed-off-by: Yang Yang <yang.yang29(a)zte.com.cn>
---
include/linux/audit.h | 3 +++
kernel/auditfilter.c | 4 ++++
kernel/auditsc.c | 36 ++++++++++++++++++++++++++++++++----
3 files changed, 39 insertions(+), 4 deletions(-)
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 82b7c11..867284c 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -302,6 +302,7 @@ extern void audit_seccomp(unsigned long syscall, long signr, int code);
extern void audit_seccomp_actions_logged(const char *names,
const char *old_names, int res);
extern void __audit_ptrace(struct task_struct *t);
+extern void audit_rule_syscall_mask_update(struct audit_krule rule, bool add);
static inline void audit_set_context(struct task_struct *task, struct audit_context *ctx)
{
@@ -599,6 +600,8 @@ static inline void audit_seccomp(unsigned long syscall, long signr, int code)
static inline void audit_seccomp_actions_logged(const char *names,
const char *old_names, int res)
{ }
+static inline void audit_rule_syscall_mask_update(struct audit_krule rule, bool add)
+{}
static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)
{ }
static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid,
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 333b3bc..0b2a8d5 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -957,6 +957,8 @@ static inline int audit_add_rule(struct audit_entry *entry)
return err;
}
+ audit_rule_syscall_mask_update(entry->rule, true);
+
if (watch) {
/* audit_filter_mutex is dropped and re-taken during this call */
err = audit_add_watch(&entry->rule, &list);
@@ -1035,6 +1037,8 @@ int audit_del_rule(struct audit_entry *entry)
goto out;
}
+ audit_rule_syscall_mask_update(e->rule, false);
+
if (e->rule.watch)
audit_remove_watch_rule(&e->rule);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index ce8c9e2..1b8ff4e 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -97,6 +97,9 @@ int audit_n_rules;
/* determines whether we collect data for signals sent */
int audit_signals;
+/* whether one syscall needs to be audited */
+u32 audit_rule_syscall_mask[NR_syscalls] = {0};
+
struct audit_aux_data {
struct audit_aux_data *next;
int type;
@@ -799,6 +802,29 @@ static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
return rule->mask[word] & bit;
}
+/**
+ * audit_rule_syscall_mask_update - update syscall mask when audit rule changes
+ * @rule: audit rule
+ * @add: add rule or delete
+ *
+ * Caller must hold audit_filter_mutex to prevent stale data.
+ */
+void audit_rule_syscall_mask_update(struct audit_krule rule, bool add)
+{
+ int i;
+
+ if (rule.listnr == AUDIT_FILTER_EXIT && !rule.watch && !rule.tree) {
+ for (i = 0; i < NR_syscalls; i++) {
+ if (unlikely(audit_in_mask(&rule, i))) {
+ if (add == true)
+ audit_rule_syscall_mask[i]++;
+ else
+ audit_rule_syscall_mask[i]--;
+ }
+ }
+ }
+}
+
/* At syscall entry and exit time, this filter is called if the
* audit_state is not low enough that auditing cannot take place, but is
* also not high enough that we already know we have to write an audit
@@ -1627,8 +1653,9 @@ void __audit_free(struct task_struct *tsk)
context->return_valid = AUDITSC_INVALID;
context->return_code = 0;
- audit_filter_syscall(tsk, context,
- &audit_filter_list[AUDIT_FILTER_EXIT]);
+ if (unlikely(audit_rule_syscall_mask[context->major]))
+ audit_filter_syscall(tsk, context,
+ &audit_filter_list[AUDIT_FILTER_EXIT]);
audit_filter_inodes(tsk, context);
if (context->current_state == AUDIT_RECORD_CONTEXT)
audit_log_exit();
@@ -1735,8 +1762,9 @@ void __audit_syscall_exit(int success, long return_code)
else
context->return_code = return_code;
- audit_filter_syscall(current, context,
- &audit_filter_list[AUDIT_FILTER_EXIT]);
+ if (unlikely(audit_rule_syscall_mask[context->major]))
+ audit_filter_syscall(current, context,
+ &audit_filter_list[AUDIT_FILTER_EXIT]);
audit_filter_inodes(current, context);
if (context->current_state == AUDIT_RECORD_CONTEXT)
audit_log_exit();
--
2.15.2
3 years, 9 months
[PATCH v2] audit: Make audit_filter_syscall() return void
by menglong8.dong＠gmail.com
From: Yang Yang <yang.yang29(a)zte.com.cn>
No invoker uses the return value of audit_filter_syscall().
So make it return void, and amend the comment of
audit_filter_syscall().
Changes since v1:
- amend the comment of audit_filter_syscall().
Signed-off-by: Yang Yang <yang.yang29(a)zte.com.cn>
Reviewed-by: Richard Guy Briggs <rgb(a)redhat.com>
---
kernel/auditsc.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index ce8c9e2279ba..434337ab6b2b 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -799,12 +799,12 @@ static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
return rule->mask[word] & bit;
}
-/* At syscall entry and exit time, this filter is called if the
- * audit_state is not low enough that auditing cannot take place, but is
- * also not high enough that we already know we have to write an audit
- * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
+/* At syscall exit time, this filter is called if the audit_state is
+ * not low enough that auditing cannot take place, but is also not
+ * high enough that we already know we have to write an audit record
+ * (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
*/
-static enum audit_state audit_filter_syscall(struct task_struct *tsk,
+static void audit_filter_syscall(struct task_struct *tsk,
struct audit_context *ctx,
struct list_head *list)
{
@@ -812,7 +812,7 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk,
enum audit_state state;
if (auditd_test_task(tsk))
- return AUDIT_DISABLED;
+ return;
rcu_read_lock();
list_for_each_entry_rcu(e, list, list) {
@@ -821,11 +821,11 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk,
&state, false)) {
rcu_read_unlock();
ctx->current_state = state;
- return state;
+ return;
}
}
rcu_read_unlock();
- return AUDIT_BUILD_CONTEXT;
+ return;
}
/*
--
2.25.1
3 years, 9 months
Occasional delayed output of events
by Burn Alting
All,
Sometimes, events recorded in /var/log/audit/audit.log appear some seconds past co-
located events which results in auparse:au_check_events() marking these events
complete before they are. An example of this can be seen below with the offending
event id 44609.
This has been plaguing me for a year or two and this morning was the first time I
still had access to the raw audit.log files (I monitor a lot of event types and the
log files roll over fairly quickly).
The example below is from a fully patched Centos 7 but I have also seen this on a
patched Fedora 32.
Has this been seen before? Do we need to re-evaluate how auparse 'completes' an
event (ie 2 seconds is too quick).
type=SYSCALL msg=audit(1609519896.824:44603):
type=EXECVE msg=audit(1609519896.824:44603):
type=CWD msg=audit(1609519896.824:44603):
type=PATH msg=audit(1609519896.824:44603):
type=PATH msg=audit(1609519896.824:44603):
type=PROCTITLE msg=audit(1609519896.824:44603):
type=SYSCALL msg=audit(1609519896.826:44604):
type=EXECVE msg=audit(1609519896.826:44604):
type=CWD msg=audit(1609519896.826:44604):
type=PATH msg=audit(1609519896.826:44604):
type=PATH msg=audit(1609519896.826:44604):
type=PROCTITLE msg=audit(1609519896.826:44604):
type=SYSCALL msg=audit(1609519801.338:44605):
type=EXECVE msg=audit(1609519801.338:44605):
type=CWD msg=audit(1609519801.338:44605):
type=PATH msg=audit(1609519801.338:44605):
type=PATH msg=audit(1609519801.338:44605):
type=PROCTITLE msg=audit(1609519801.338:44605):
type=SYSCALL msg=audit(1609519900.159:44606):
type=EXECVE msg=audit(1609519900.159:44606):
type=CWD msg=audit(1609519900.159:44606):
type=PATH msg=audit(1609519900.159:44606):
type=PATH msg=audit(1609519900.159:44606):
type=PROCTITLE msg=audit(1609519900.159:44606):
type=SYSCALL msg=audit(1609519900.161:44607):
type=EXECVE msg=audit(1609519900.161:44607):
type=CWD msg=audit(1609519900.161:44607):
type=PATH msg=audit(1609519900.161:44607):
type=PATH msg=audit(1609519900.161:44607):
type=PROCTITLE msg=audit(1609519900.161:44607):
type=SYSCALL msg=audit(1609519896.829:44609):
type=EXECVE msg=audit(1609519896.829:44609):
type=CWD msg=audit(1609519896.829:44609):
type=SYSCALL msg=audit(1609519900.163:44608):
type=PATH msg=audit(1609519896.829:44609):
type=EXECVE msg=audit(1609519900.163:44608):
type=CWD msg=audit(1609519900.163:44608):
type=PATH msg=audit(1609519896.829:44609):
type=PROCTITLE msg=audit(1609519896.829:44609):
type=PATH msg=audit(1609519900.163:44608):
type=PATH msg=audit(1609519900.163:44608):
type=PROCTITLE msg=audit(1609519900.163:44608):
type=CRED_DISP msg=audit(1609519900.170:44610):
type=SYSCALL msg=audit(1609519900.170:44611):
type=EXECVE msg=audit(1609519900.170:44611):
type=CWD msg=audit(1609519900.170:44611):
type=PATH msg=audit(1609519900.170:44611):
type=PATH msg=audit(1609519900.170:44611):
type=PROCTITLE msg=audit(1609519900.170:44611):
which results in an ausearch -i output sequence of
----
type=PROCTITLE msg=audit(02/01/21 03:51:36.826:44604)
type=PATH msg=audit(02/01/21 03:51:36.826:44604)
type=PATH msg=audit(02/01/21 03:51:36.826:44604)
type=CWD msg=audit(02/01/21 03:51:36.826:44604)
type=EXECVE msg=audit(02/01/21 03:51:36.826:44604)
type=SYSCALL msg=audit(02/01/21 03:51:36.826:44604)
----
type=CWD msg=audit(02/01/21 03:51:36.829:44609)
type=EXECVE msg=audit(02/01/21 03:51:36.829:44609)
type=SYSCALL msg=audit(02/01/21 03:51:36.829:44609)
----
type=PROCTITLE msg=audit(02/01/21 03:51:36.829:44609)
type=PATH msg=audit(02/01/21 03:51:36.829:44609)
type=PATH msg=audit(02/01/21 03:51:36.829:44609)
----
type=PROCTITLE msg=audit(02/01/21 03:51:40.159:44606)
type=PATH msg=audit(02/01/21 03:51:40.159:44606)
type=PATH msg=audit(02/01/21 03:51:40.159:44606)
type=CWD msg=audit(02/01/21 03:51:40.159:44606)
type=EXECVE msg=audit(02/01/21 03:51:40.159:44606)
type=SYSCALL msg=audit(02/01/21 03:51:40.159:44606)
----
type=PROCTITLE msg=audit(02/01/21 03:51:40.161:44607)
type=PATH msg=audit(02/01/21 03:51:40.161:44607)
type=PATH msg=audit(02/01/21 03:51:40.161:44607)
type=CWD msg=audit(02/01/21 03:51:40.161:44607)
type=EXECVE msg=audit(02/01/21 03:51:40.161:44607)
type=SYSCALL msg=audit(02/01/21 03:51:40.161:44607)
----
type=PROCTITLE msg=audit(02/01/21 03:51:40.163:44608)
type=PATH msg=audit(02/01/21 03:51:40.163:44608)
type=PATH msg=audit(02/01/21 03:51:40.163:44608)
type=CWD msg=audit(02/01/21 03:51:40.163:44608)
type=EXECVE msg=audit(02/01/21 03:51:40.163:44608)
type=SYSCALL msg=audit(02/01/21 03:51:40.163:44608)
----
type=CRED_DISP msg=audit(02/01/21 03:51:40.170:44610)
Regards
Burn
3 years, 9 months
[PATCH] audit: Make audit_filter_syscall() return void
by menglong8.dong＠gmail.com
From: Yang Yang <yang.yang29(a)zte.com.cn>
No invoker users the return value of audit_filter_syscall().
So make it return void.
Signed-off-by: Yang Yang <yang.yang29(a)zte.com.cn>
---
kernel/auditsc.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index ce8c9e2279ba..c8e16b9c0f21 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -804,7 +804,7 @@ static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
* also not high enough that we already know we have to write an audit
* record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
*/
-static enum audit_state audit_filter_syscall(struct task_struct *tsk,
+static void audit_filter_syscall(struct task_struct *tsk,
struct audit_context *ctx,
struct list_head *list)
{
@@ -812,7 +812,7 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk,
enum audit_state state;
if (auditd_test_task(tsk))
- return AUDIT_DISABLED;
+ return;
rcu_read_lock();
list_for_each_entry_rcu(e, list, list) {
@@ -821,11 +821,11 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk,
&state, false)) {
rcu_read_unlock();
ctx->current_state = state;
- return state;
+ return;
}
}
rcu_read_unlock();
- return AUDIT_BUILD_CONTEXT;
+ return;
}
/*
--
2.25.1
3 years, 9 months
[RFC,v1,1/1] audit: speed up syscall rule match while exiting syscall
by yang.yang29＠zte.com.cn
From 82ebcf43481be21ee3e32ec1749b42f651737880 Mon Sep 17 00:00:00 2001
From: Yang Yang <yang.yang29(a)zte.com.cn>
Date: Wed, 13 Jan 2021 20:18:04 +0800
Subject: [PATCH] [RFC,v1,1/1] speed up syscall rule match while exiting syscall
If user add any syscall rule, in all syscalls, audit_filter_syscall()
traverses struct list_head audit_filter_list to find out whether current
syscall match one rule. This takes o(n), which is not necessary, specially
for user who add a very few syscall rules. On the other hand, user may not
much care about rule add/delete speed. So do o(n) calculate at rule changing,
and ease the burden of audit_filter_syscall().
Define audit_syscall[NR_syscalls], every element stands for one syscall.
audit_filter_syscall() checks audit_syscall[NR_syscalls].
audit_syscall[n] == 0 indicates no rule audit syscall n, do a quick exit.
audit_syscall[n] > 0 indicates at least one rule audit syscall n.
audit_syscall[n] update when syscall rule changes.
Signed-off-by: Yang Yang <yang.yang29(a)zte.com.cn>
---
include/linux/audit.h | 2 ++
kernel/audit.c | 2 ++
kernel/auditfilter.c | 16 ++++++++++++++++
kernel/auditsc.c | 9 ++++++++-
4 files changed, 28 insertions(+), 1 deletion(-)
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 82b7c11..56a8c61 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -549,6 +549,8 @@ static inline void audit_log_nfcfg(const char *name, u8 af,
extern int audit_n_rules;
extern int audit_signals;
+extern u32 audit_syscall[NR_syscalls];
+extern int audit_in_mask(const struct audit_krule *rule, unsigned long val);
#else /* CONFIG_AUDITSYSCALL */
static inline int audit_alloc(struct task_struct *task)
{
diff --git a/kernel/audit.c b/kernel/audit.c
index 1ffc2e0..d233a95 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -208,6 +208,8 @@ struct audit_reply {
struct sk_buff *skb;
};
+u32 audit_syscall[NR_syscalls] = {0};
+
/**
* auditd_test_task - Check to see if a given task is an audit daemon
* @task: the task to check
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 333b3bc..c7e60cd 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -936,6 +936,7 @@ static inline int audit_add_rule(struct audit_entry *entry)
int err = 0;
#ifdef CONFIG_AUDITSYSCALL
int dont_count = 0;
+ int i = 0;
/* If any of these, don't count towards total */
switch(entry->rule.listnr) {
@@ -957,6 +958,13 @@ static inline int audit_add_rule(struct audit_entry *entry)
return err;
}
+#ifdef CONFIG_AUDITSYSCALL
+ if (entry->rule.listnr == AUDIT_FILTER_EXIT && !watch && !tree) {
+ for (i = 0; i < NR_syscalls; i++)
+ audit_syscall[i] += !(!audit_in_mask(&entry->rule, i));
+ }
+#endif
+
if (watch) {
/* audit_filter_mutex is dropped and re-taken during this call */
err = audit_add_watch(&entry->rule, &list);
@@ -1018,6 +1026,7 @@ int audit_del_rule(struct audit_entry *entry)
int ret = 0;
#ifdef CONFIG_AUDITSYSCALL
int dont_count = 0;
+ int i = 0;
/* If any of these, don't count towards total */
switch(entry->rule.listnr) {
@@ -1035,6 +1044,13 @@ int audit_del_rule(struct audit_entry *entry)
goto out;
}
+#ifdef CONFIG_AUDITSYSCALL
+ if (entry->rule.listnr == AUDIT_FILTER_EXIT && !e->rule.watch && !e->rule.tree) {
+ for (i = 0; i < NR_syscalls; i++)
+ audit_syscall[i] -= !(!audit_in_mask(&entry->rule, i));
+ }
+#endif
+
if (e->rule.watch)
audit_remove_watch_rule(&e->rule);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index ce8c9e2..2a74436 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -783,7 +783,7 @@ static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)
return AUDIT_BUILD_CONTEXT;
}
-static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
+int audit_in_mask(const struct audit_krule *rule, unsigned long val)
{
int word, bit;
@@ -814,6 +814,13 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk,
if (auditd_test_task(tsk))
return AUDIT_DISABLED;
+ mutex_lock(&audit_filter_mutex);
+ if (!audit_syscall[ctx->major]) {
+ mutex_unlock(&audit_filter_mutex);
+ return AUDIT_BUILD_CONTEXT;
+ }
+ mutex_unlock(&audit_filter_mutex);
+
rcu_read_lock();
list_for_each_entry_rcu(e, list, list) {
if (audit_in_mask(&e->rule, ctx->major) &&
--
2.15.2
3 years, 9 months
[RFC PATCH] audit.spec: create audit group for log read access
by Enzo Matsumiya
This patch introduces a new "audit" group.
The purpose of this group is to restrict read access to audit.log file.
No users are added to this group by default in this patch; it's up to
the user to do so.
One use case for this is to use AppArmor denial notifications (aa-notify),
which currently requires sudo. So, with this patch, instead of
modifying sudo configuration, the user who wants to run aa-notify to
read audit.log can just be added to the new audit group.
This patch already uses systemd-sysuser facilities to create system
groups.
Signed-off-by: Enzo Matsumiya <ematsumiya(a)suse.de>
---
audit.spec | 27 +++++++++++++++++++++++++--
init.d/auditd.conf | 2 +-
system-group-audit.conf | 2 ++
3 files changed, 28 insertions(+), 3 deletions(-)
create mode 100644 system-group-audit.conf
diff --git a/audit.spec b/audit.spec
index 23153a60dc80..be6490b7ad09 100644
--- a/audit.spec
+++ b/audit.spec
@@ -7,22 +7,35 @@ License: GPLv2+
Group: System Environment/Daemons
URL: http://people.redhat.com/sgrubb/audit/
Source0: http://people.redhat.com/sgrubb/audit/%{name}-%{version}.tar.gz
+Source1: system-group-audit.conf
BuildRequires: gcc swig
BuildRequires: golang
BuildRequires: krb5-devel libcap-ng-devel
BuildRequires: kernel-headers >= 2.6.29
BuildRequires: systemd
+BuildRequires: sysuser-tools
Requires: %{name}-libs = %{version}-%{release}
Requires(post): systemd coreutils
Requires(preun): systemd initscripts
Requires(postun): systemd coreutils initscript
+Requires: group(audit)
%description
The audit package contains the user space utilities for
storing and searching the audit records generated by
the audit subsystem in the Linux 2.6 and later kernels.
+%package -n system-group-audit
+Summary: System group 'audit'
+License: LGPL-2.1-or-later
+Group: System/Fhs
+Provides: group(audit)
+%sysusers_requires
+
+%description -n system-group-audit
+This package contains the system group 'audit' for restrict read access to logs.
+
%package libs
Summary: Dynamic library for libaudit
License: LGPLv2+
@@ -98,13 +111,17 @@ behavior.
make CFLAGS="%{optflags}" %{?_smp_mflags}
+%sysusers_generate_pre %{SOURCE1} audit
+
%install
mkdir -p $RPM_BUILD_ROOT/{sbin,etc/audit/plugins.d,etc/audit/rules.d}
mkdir -p $RPM_BUILD_ROOT/%{_mandir}/{man5,man8}
mkdir -p $RPM_BUILD_ROOT/%{_lib}
mkdir -p $RPM_BUILD_ROOT/%{_libdir}/audit
-mkdir --mode=0700 -p $RPM_BUILD_ROOT/%{_var}/log/audit
+mkdir --mode=0750 -p $RPM_BUILD_ROOT/%{_var}/log/audit
mkdir -p $RPM_BUILD_ROOT/%{_var}/spool/audit
+mkdir -p $RPM_BUILD_ROOT/%{_sysusersdir}
+install -m 0644 %{SOURCE1} $RPM_BUILD_ROOT/%{_sysusersdir}/
make DESTDIR=$RPM_BUILD_ROOT install
mkdir -p $RPM_BUILD_ROOT/%{_libdir}
@@ -143,6 +160,8 @@ if [ "$files" -eq 0 ] ; then
fi
%systemd_post auditd.service
+%pre -n system-group-audit -f audit.pre
+
%preun
%systemd_preun auditd.service
if [ $1 -eq 0 ]; then
@@ -228,7 +247,8 @@ fi
%attr(750,root,root) %{_libexecdir}/initscripts/legacy-actions/auditd/state
%attr(750,root,root) %{_libexecdir}/initscripts/legacy-actions/auditd/stop
%ghost %{_localstatedir}/run/auditd.state
-%attr(-,root,-) %dir %{_var}/log/audit
+%attr(750,root,audit) %dir %{_var}/log/audit
+%ghost %config(noreplace) %attr(640,root,audit) %dir %{_var}/log/audit/audit.log
%attr(750,root,root) %dir /etc/audit
%attr(750,root,root) %dir /etc/audit/rules.d
%attr(750,root,root) %dir /etc/audit/plugins.d
@@ -238,6 +258,9 @@ fi
%config(noreplace) %attr(640,root,root) /etc/audit/audit-stop.rules
%config(noreplace) %attr(640,root,root) /etc/audit/plugins.d/af_unix.conf
+%files -n system-group-audit
+%{_sysusersdir}/system-group-audit.conf
+
%files -n audispd-plugins
%config(noreplace) %attr(640,root,root) /etc/audit/plugins.d/audispd-zos-remote.conf
%config(noreplace) %attr(640,root,root) /etc/audit/zos-remote.conf
diff --git a/init.d/auditd.conf b/init.d/auditd.conf
index ff6a3352854f..0c68c00322f9 100644
--- a/init.d/auditd.conf
+++ b/init.d/auditd.conf
@@ -5,7 +5,7 @@
local_events = yes
write_logs = yes
log_file = /var/log/audit/audit.log
-log_group = root
+log_group = audit
log_format = ENRICHED
flush = INCREMENTAL_ASYNC
freq = 50
diff --git a/system-group-audit.conf b/system-group-audit.conf
new file mode 100644
index 000000000000..ea2ffb04b405
--- /dev/null
+++ b/system-group-audit.conf
@@ -0,0 +1,2 @@
+# Type Name ID GECOS [HOME]
+g audit -
--
2.30.0
3 years, 9 months
[RFC] audit.spec: create audit group for log read access
by Enzo Matsumiya
Hi,
We (SUSE) would like to introduce an "audit" group for log read access.
This would be handled only by patching the .spec file to create the
group and modify the permissions of the default log dir/file to:
drwxr-x--- 1 root audit 322 25. Okt 21:06 /var/log/audit/
-rw-r----- 1 root audit 1815972 26. Okt 22:23 /var/log/audit/audit.log
No source code modifications are required, as log_group_parser() should
handle invalid entries.
If an enforcement or warning is required for when log_group is not
using the default "audit" group, it should be easy to do as well.
For those wondering, Common Criteria seems to be fine with this
modification.
Excerpt from SUSE's CC certification (RH's seems to match):
---- begin ----
6.2.1.4 Restricted audit review (FAU_SAR.2)
FAU_SAR.2.1 The TSF shall prohibit all users read access to the audit records, except those
users that have been granted explicit read-access.
Application Note: The protection of the audit records is based on the Unix permission bit
settings defined by FDP_ACC.1(PSO) supported by FDP_ACF.1(PSO).
---- end ----
Please let me know of your concerns, if any.
I have a working patch that I can submit right away in case this gets an
ok.
Cheers,
Enzo
3 years, 9 months
2nd Round AuditRules Questions
by Joe Wulf
1. The rules for monitoring '/etc/passwd', '/etc/shadow', '/etc/group', '/etc/gshadow' exist. Shouldn't corresponding rules also exist for the same four files which also have a dash/hyphen appended to them (i.e. '/etc/passwd-', etc...)?
2. By adding 'audit=1' to grub kernel boot param's---can I then safely eliminate this piece from all audit rules: '-F auid!=4294967295'?Conversely, what harm would it do to 'just leave it'? It would, in some cases, satisfy certain vulnerability scanning tools seeking exact syntax compliance, right?
Thank you.
R,-Joe Wulf
3 years, 9 months
