[PATCH v38 00/39] 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.
There are additional changes required for SELinux and Smack
to coexist. These are primarily in the networking code and
will be addressed after these changes are upstream.
v38: Rebase to 6.0-rc7
- Discard the implementation of /proc/self/attr/context
- Discard the implementation of /proc/self/attr/display_lsm
- Implement a system call lsm_self_attr() which provides
a complete list of LSM process attributes.
- Implement a system call lsm_module_list() which provides
a list of the security modules active on the system.
- Implement a pair of prctl() options PR_LSM_ATTR_SET
and PR_LSM_ATTR_GET. These are used to control the LSM
that provides the values in /proc/.../attr entries.
- Make more of the infrastructure data changes early in the
patch set in support of the new system calls.
- Add a user interface header uapi/linux/lsm.h which contains
the format of data provided by lsm_self_attr() and the
integer LSM identifier values.
v37: Rebase to 5.19-rc3
- Audit changes should be complete, all comments have been
addressed.
- Address indexing an empty array for the case where no
built in security modules require data in struct lsmblob.
- Fix a few checkpatch complaints.
v36: Rebase to 5.19-rc1
- Yet another rework of the audit changes. Rearranging how the
timestamp is managed allows auxiliary records to be generated
correctly with a minimum of fuss.
- In the end no LSM interface scaffolding remains. Secids have
been replaced with lsmblob structures in all cases, including
IMA and NetLabel.
v35: Rebase to 5.18-rc2
- Address the case where CONFIG_SECURITY is enabled but
no security modules that use secid slots are included.
The resulting blob.secid[0] instances, although never
present in a call path, raised concerns.
- Address the case in interface_lsm where the BPF module
returns -EINVAL, resulting in a failed setting of the
value that would be otherwise allowed.
v34: Rebase to 5.18-rc1
- Incorporate feedback on the audit generation.
v33:
- Rework the supplimental audit record generation once more,
this time taking pseudo-code provided by Paul Moore as a
basis. The resulting code is considerably simpler and fits
better with the existing code flow.
v32: Rebase to 5.17-rc2
- Incorporate additional feedback from v30.
v31: Rebase to 5.16-rc4
- Incorporate feedback from Paul Moore on the audit
component changes.
v30: Rebase to 5.16-rc1
- Replace the integrity sub-system reuse of the audit
subsystem event matching functions with IMA specific
functions. This is done because audit needs to maintain
information about multiple security modules in audit
rules while IMA to restricts the information to a single
security module.
- The binder hooks have been changed and are no longer
called with sufficient information to identify the
interface_lsm. Pass that information in the binder
message, and use that in the compatibility decision.
- Refactor the audit changes.
v29: Rebase to 5.15-rc1
- Rework the supplimental audit record generation. Attach
a list of supplimental data to the audit_buffer and
generate the auxiliary records as needed on event end.
This should be usable for other auxiliary data, such as
container IDs. There is other ongoing audit work that
will require integration with this.
v28: Rebase to 5.14-rc2
- Provide IMA rules bounds checking (patch 04)
- Quote contexts in MAC_TASK_CONTEXTS and MAC_OBJ_CONTEXTS
audit records because of AppArmor's use of '=' in context
values. (patch 22,23)
v27: Fixes for landlock (patch 02)
- Rework the subject audit record generation. This version is
simpler and reflects feedback from Paul Moore. (patch 22)
v26: Rebase to 5.13-rc1
- Include the landlock security module.
- Accomodate change from security_task_getsecid() to
security_task_getsecid_obj() and security_task_getsecid_subj().
v25: Rebase to 5.12-rc2
Incorporate feedback from v24
- The IMA team suggested improvements to the integrity rule
processing.
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 changes the LSM registration interface to pass a
structure lsm_id containing the name of the module instead of
just the LSM name itself.
Patch 02 introduces uapi/linux/lsm.h and numeric LSM identifiers.
The numeric ID is added to the lsm_id structure.
Patch 03 Adds the information about which process attributes are
supported by each LSM to the lsm_id structure.
Patch 04 introduces a table of LSM attribute data.
Patch 05 changes security_[gs]etprocattr() to use the LSM ID rather
than the LSM name.
Patch 06 implements the lsm_self_attr() system call.
Patch 07 separates the audit rule processing from the
integrity rule processing. They were never really the
same, but void pointers could hide that. The changes
following use the rule pointers differently in audit
and IMA, so keeping the code common is not a good idea.
Patch 08 moves management of the sock security blob
from the individual modules to the infrastructure.
Patches 09-10 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 11 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 12-19 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 20 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 prctl() options
PR_LSM_ATTR_[GS]ET get and set which security module to show.
Setting the value requires that all modules using the /proc
interfaces allow the transition. The interface LSM of other
processess can be neither read nor written.
Patch 21 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 22-25 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.
Patch 26 converts the Netlabel code to save lsmblob structures
instead of secids. 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 27 adds checks to the binder hooks which verify
that both ends of a transaction use the same interface LSM.
Patch 28 adds a parameter to security_secid_to_secctx()
that indicates which of the security modules should be used
to provide the context.
Patches 29-33 update the audit system to better handle auxiliary
records. This requires rearranging the timestamp and serial number
handling. The skb pointer used to collect audit data is replaced
by a list of skb pointers.
Patch 34 adds a supplimental audit record for subject
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_TASK_CONTEXTS record identifies the security module
with the data: subj_selinux=xyz_t subj_apparmor=abc.
An example of the MAC_TASK_CONTEXTS (1420) record is:
type=UNKNOWN[1420]
msg=audit(1600880931.832:113)
subj_apparmor==unconfined
subj_smack=_
Patch 35 adds a supplimental audit record for object
LSM data when there are multiple security modules with such data.
The AUDIT_MAC_OBJ_CONTEXTS record is used in conjuction The
with a "obj=?" field to identify the object data.
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_OBJ_CONTEXTS (1421) record is:
type=UNKNOWN[1421]
msg=audit(1601152467.009:1050):
obj_selinux=unconfined_u:object_r:user_home_t:s0
Patches 36-37 clean out scaffolding code.
With all interference on the AppArmor hooks removed,
Patch 38 removes the exclusive bit from AppArmor. An unnecessary
stub hook was also removed.
Patch 39 adds a system call lsm_module_list() that provides a set
of integer LSM ID values describing what is active on the system.
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-6.0-rc7-38
Casey Schaufler (39):
LSM: Identify modules by more than name
LSM: Add an LSM identifier for external use
LSM: Identify the process attributes for each module
LSM: Maintain a table of LSM attribute data
proc: Use lsmids instead of lsm names for attrs
LSM: lsm_self_attr syscall for LSM self attributes
integrity: disassociate ima_filter_rule from security_audit_rule
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_current_getsecid
LSM: Use lsmblob in security_inode_getsecid
LSM: Use lsmblob in security_cred_getsecid
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
Use lsmcontext in security_dentry_init_security
LSM: security_secid_to_secctx in netlink netfilter
NET: Store LSM netlabel data in a lsmblob
binder: Pass LSM identifier for confirmation
LSM: security_secid_to_secctx module selection
Audit: Keep multiple LSM data in audit_names
Audit: Create audit_stamp structure
LSM: Add a function to report multiple LSMs
Audit: Allow multiple records in an audit_buffer
Audit: Add record for multiple task security contexts
audit: multiple subject lsm values for netlabel
Audit: Add record for multiple object contexts
netlabel: Use a struct lsmblob in audit data
LSM: Removed scaffolding function lsmcontext_init
AppArmor: Remove the exclusive flag
LSM: Create lsm_module_list system call
Documentation/ABI/testing/ima_policy | 8 +-
arch/x86/entry/syscalls/syscall_64.tbl | 2 +
drivers/android/binder.c | 47 ++-
drivers/android/binder_internal.h | 1 +
fs/ceph/super.h | 3 +-
fs/ceph/xattr.c | 15 +-
fs/fuse/dir.c | 35 +-
fs/nfs/dir.c | 2 +-
fs/nfs/inode.c | 17 +-
fs/nfs/internal.h | 8 +-
fs/nfs/nfs4proc.c | 14 +-
fs/nfs/nfs4xdr.c | 22 +-
fs/nfsd/nfs4xdr.c | 20 +-
fs/proc/base.c | 29 +-
fs/proc/internal.h | 2 +-
include/linux/audit.h | 21 +-
include/linux/cred.h | 3 +-
include/linux/lsm_hooks.h | 15 +-
include/linux/nfs4.h | 8 +-
include/linux/nfs_fs.h | 2 +-
include/linux/security.h | 292 +++++++++++--
include/linux/syscalls.h | 2 +
include/net/netlabel.h | 10 +-
include/net/scm.h | 15 +-
include/uapi/asm-generic/unistd.h | 8 +-
include/uapi/linux/audit.h | 2 +
include/uapi/linux/lsm.h | 67 +++
include/uapi/linux/prctl.h | 4 +
kernel/audit.c | 261 +++++++++---
kernel/audit.h | 18 +-
kernel/auditfilter.c | 29 +-
kernel/auditsc.c | 160 +++----
kernel/cred.c | 12 +-
kernel/sys_ni.c | 4 +
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_kapi.c | 6 +-
net/netlabel/netlabel_unlabeled.c | 98 +++--
net/netlabel/netlabel_unlabeled.h | 2 +-
net/netlabel/netlabel_user.c | 10 +-
net/netlabel/netlabel_user.h | 2 +-
security/Makefile | 1 +
security/apparmor/include/apparmor.h | 3 +-
security/apparmor/include/net.h | 6 +-
security/apparmor/lsm.c | 110 ++---
security/apparmor/net.c | 2 +-
security/bpf/hooks.c | 14 +-
security/commoncap.c | 9 +-
security/integrity/ima/ima.h | 32 +-
security/integrity/ima/ima_api.c | 6 +-
security/integrity/ima/ima_appraise.c | 11 +-
security/integrity/ima/ima_main.c | 62 +--
security/integrity/ima/ima_policy.c | 92 +++-
security/landlock/cred.c | 2 +-
security/landlock/fs.c | 2 +-
security/landlock/ptrace.c | 2 +-
security/landlock/setup.c | 7 +
security/landlock/setup.h | 1 +
security/loadpin/loadpin.c | 10 +-
security/lockdown/lockdown.c | 9 +-
security/lsm_syscalls.c | 206 +++++++++
security/safesetid/lsm.c | 10 +-
security/security.c | 539 +++++++++++++++++++++---
security/selinux/hooks.c | 115 +++--
security/selinux/include/classmap.h | 3 +-
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 | 85 ++--
security/smack/smack_netfilter.c | 4 +-
security/smack/smackfs.c | 12 +-
security/tomoyo/tomoyo.c | 10 +-
security/yama/yama_lsm.c | 9 +-
81 files changed, 2063 insertions(+), 758 deletions(-)
create mode 100644 include/uapi/linux/lsm.h
create mode 100644 security/lsm_syscalls.c
--
2.37.3
1 year, 2 months
- 7
- 67
[PATCH v5 0/3] fanotify: Allow user space to pass back additional audit info
by Richard Guy Briggs
The Fanotify API can be used for access control by requesting permission
event notification. The user space tooling that uses it may have a
complicated policy that inherently contains additional context for the
decision. If this information were available in the audit trail, policy
writers can close the loop on debugging policy. Also, if this additional
information were available, it would enable the creation of tools that
can suggest changes to the policy similar to how audit2allow can help
refine labeled security.
This patchset defines a new flag (FAN_INFO) and new extensions that
define additional information which are appended after the response
structure returned from user space on a permission event. The appended
information is organized with headers containing a type and size that
can be delegated to interested subsystems. One new information type is
defined to audit the triggering rule number.
A newer kernel will work with an older userspace and an older kernel
will behave as expected and reject a newer userspace, leaving it up to
the newer userspace to test appropriately and adapt as necessary.
The audit function was updated to log the additional information in the
AUDIT_FANOTIFY record. The following are examples of the new record
format:
type=FANOTIFY msg=audit(1600385147.372:590): resp=2 fan_type=1 fan_info=3137 subj_trust=3 obj_trust=5
type=FANOTIFY msg=audit(1659730979.839:284): resp=1 fan_type=0 fan_info=3F subj_trust=? obj_trust=?
changelog:
v1:
- first version by Steve Grubb <sgrubb(a)redhat.com>
Link: https://lore.kernel.org/r/2042449.irdbgypaU6@x2
v2:
- enhancements suggested by Jan Kara <jack(a)suse.cz>
- 1/3 change %d to %u in pr_debug
- 2/3 change response from __u32 to __u16
- mod struct fanotify_response and fanotify_perm_event add extra_info_type, extra_info_buf
- extra_info_buf size max FANOTIFY_MAX_RESPONSE_EXTRA_LEN, add struct fanotify_response_audit_rule
- extend debug statements
- remove unneeded macros
- [internal] change interface to finish_permission_event() and process_access_response()
- 3/3 update format of extra information
- [internal] change interface to audit_fanotify()
- change ctx_type= to fan_type=
Link: https://lore.kernel.org/r/cover.1651174324.git.rgb@redhat.com
v3:
- 1/3 switch {,__}audit_fanotify() from uint to u32
- 2/3 re-add fanotify_get_response switch case FAN_DENY: to avoid unnecessary churn
- add FAN_EXTRA flag to indicate more info and break with old kernel
- change response from u16 to u32 to avoid endian issues
- change extra_info_buf to union
- move low-cost fd check earlier
- change FAN_RESPONSE_INFO_AUDIT_NONE to FAN_RESPONSE_INFO_NONE
- switch to u32 for internal and __u32 for uapi
Link: https://lore.kernel.org/all/cover.1652730821.git.rgb@redhat.com
v4:
- scrap FAN_INVALID_RESPONSE_MASK in favour of original to catch invalid response == 0
- introduce FANOTIFY_RESPONSE_* macros
- uapi: remove union
- keep original struct fanotify_response, add fan_info infra starting with audit reason
- uapi add struct fanotify_response_info_header{type/pad/len} and struct fanotify_response_info_audit_rule{hdr/rule}
- rename fan_ctx= to fan_info=, FAN_EXTRA to FAN_INFO
- change event struct from type/buf to len/buf
- enable multiple info extensions in one message
- hex encode fan_info in __audit_fanotify()
- record type FANOTIFY extended to "type=FANOTIFY msg=audit(1659730979.839:284): resp=1 fan_type=0 fan_info=3F"
Link: https://lore.kernel.org/all/cover.1659996830.git.rgb@redhat.com
v5:
- fixed warnings in p2/4 and p3/4 found by <lkp(a)intel.com>
- restore original behaviour for !FAN_INFO case and fanotify_get_response()
- rename member audit_rule to rule_number
- eliminate memory leak of info_buf on failure (no longer dynamic)
- rename buf:info, count:info_len, c:remain, ib:infop
- fix pr_debug
- return -ENOENT on FAN_INFO and fd==FAN_NOFD to signal new kernel
- fanotify_write() remove redundant size check
- add u32 subj_trust obj_trust fields with unknown value "2"
- split out to helper process_access_response_info()
- restore finish_permission_event() response_struct to u32
- assume and enforce one rule to audit, pass struct directly to __audit_fanotify()
- change fanotify_perm_event struct to union hdr/audir_rule
- add vspace to fanotify_write() and process_access_response_info()
- squash 3/4 with 4/4
- fix v3 and v4 links
Link: https://lore.kernel.org/all/cover.1670606054.git.rgb@redhat.com
Richard Guy Briggs (3):
fanotify: Ensure consistent variable type for response
fanotify: define struct members to hold response decision context
fanotify,audit: Allow audit to use the full permission event response
fs/notify/fanotify/fanotify.c | 8 ++-
fs/notify/fanotify/fanotify.h | 6 +-
fs/notify/fanotify/fanotify_user.c | 88 ++++++++++++++++++++++--------
include/linux/audit.h | 9 +--
include/linux/fanotify.h | 5 ++
include/uapi/linux/fanotify.h | 30 +++++++++-
kernel/auditsc.c | 25 ++++++++-
7 files changed, 138 insertions(+), 33 deletions(-)
--
2.27.0
1 year, 4 months
- 4
- 19
[PATCH v2] bpf: restore the ebpf program ID for BPF_AUDIT_UNLOAD and PERF_BPF_EVENT_PROG_UNLOAD
by Paul Moore
When changing the ebpf program put() routines to support being called
from within IRQ context the program ID was reset to zero prior to
calling the perf event and audit UNLOAD record generators, which
resulted in problems as the ebpf program ID was bogus (always zero).
This patch resolves this by adding a new flag, bpf_prog::valid_id, to
indicate when the bpf_prog_aux ID field is valid; it is set to true/1
in bpf_prog_alloc_id() and set to false/0 in bpf_prog_free_id(). In
order to help ensure that access to the bpf_prog_aux ID field takes
into account the new valid_id flag, the bpf_prog_aux ID field is
renamed to bpf_prog_aux::__id and a getter function,
bpf_prog_get_id(), was created and all users of bpf_prog_aux::id were
converted to the new caller. Exceptions to this include some of the
internal ebpf functions and the xdp trace points, although the latter
still take into account the valid_id flag.
I also modified the bpf_audit_prog() logic used to associate the
AUDIT_BPF record with other associated records, e.g. @ctx != NULL.
Instead of keying off the operation, it now keys off the execution
context, e.g. '!in_irg && !irqs_disabled()', which is much more
appropriate and should help better connect the UNLOAD operations with
the associated audit state (other audit records).
Fixes: d809e134be7a ("bpf: Prepare bpf_prog_put() to be called from irq context.")
Reported-by: Burn Alting <burn.alting(a)iinet.net.au>
Reported-by: Jiri Olsa <olsajiri(a)gmail.com>
Signed-off-by: Paul Moore <paul(a)paul-moore.com>
--
* v2
- change subj
- add mention of the perf regression
- drop the dedicated program audit ID
- add the bpf_prog::valid_id flag, bpf_prog_get_id() getter
- convert prog ID users to new ID getter
* v1
- subj was: "bpf: restore the ebpf audit UNLOAD id field"
- initial draft
---
drivers/net/netdevsim/bpf.c | 6 ++++--
include/linux/bpf.h | 11 +++++++++--
include/linux/bpf_verifier.h | 2 +-
include/trace/events/xdp.h | 4 ++--
kernel/bpf/arraymap.c | 2 +-
kernel/bpf/bpf_struct_ops.c | 2 +-
kernel/bpf/cgroup.c | 2 +-
kernel/bpf/core.c | 2 +-
kernel/bpf/cpumap.c | 2 +-
kernel/bpf/devmap.c | 2 +-
kernel/bpf/syscall.c | 27 +++++++++++++++------------
kernel/events/core.c | 6 +++++-
kernel/trace/bpf_trace.c | 2 +-
net/core/dev.c | 2 +-
net/core/filter.c | 3 ++-
net/core/rtnetlink.c | 2 +-
net/core/sock_map.c | 2 +-
net/ipv6/seg6_local.c | 3 ++-
net/sched/act_bpf.c | 2 +-
net/sched/cls_bpf.c | 2 +-
20 files changed, 52 insertions(+), 34 deletions(-)
diff --git a/drivers/net/netdevsim/bpf.c b/drivers/net/netdevsim/bpf.c
index 50854265864d..2795f03f5f34 100644
--- a/drivers/net/netdevsim/bpf.c
+++ b/drivers/net/netdevsim/bpf.c
@@ -109,7 +109,7 @@ nsim_bpf_offload(struct netdevsim *ns, struct bpf_prog *prog, bool oldprog)
"bad offload state, expected offload %sto be active",
oldprog ? "" : "not ");
ns->bpf_offloaded = prog;
- ns->bpf_offloaded_id = prog ? prog->aux->id : 0;
+ ns->bpf_offloaded_id = prog ? bpf_prog_get_id(prog) : 0;
nsim_prog_set_loaded(prog, true);
return 0;
@@ -221,6 +221,7 @@ static int nsim_bpf_create_prog(struct nsim_dev *nsim_dev,
struct nsim_bpf_bound_prog *state;
char name[16];
int ret;
+ u32 id;
state = kzalloc(sizeof(*state), GFP_KERNEL);
if (!state)
@@ -239,7 +240,8 @@ static int nsim_bpf_create_prog(struct nsim_dev *nsim_dev,
return ret;
}
- debugfs_create_u32("id", 0400, state->ddir, &prog->aux->id);
+ id = bpf_prog_get_id(prog);
+ debugfs_create_u32("id", 0400, state->ddir, &id);
debugfs_create_file("state", 0400, state->ddir,
&state->state, &nsim_bpf_string_fops);
debugfs_create_bool("loaded", 0400, state->ddir, &state->is_loaded);
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 9e7d46d16032..18e965bd7db9 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1102,7 +1102,7 @@ struct bpf_prog_aux {
u32 max_pkt_offset;
u32 max_tp_access;
u32 stack_depth;
- u32 id;
+ u32 __id; /* access via bpf_prog_get_id() to check bpf_prog::valid_id */
u32 func_cnt; /* used by non-func prog as the number of func progs */
u32 func_idx; /* 0 for non-func prog, the index in func array for func prog */
u32 attach_btf_id; /* in-kernel BTF type id to attach to */
@@ -1197,7 +1197,8 @@ struct bpf_prog {
enforce_expected_attach_type:1, /* Enforce expected_attach_type checking at attach time */
call_get_stack:1, /* Do we call bpf_get_stack() or bpf_get_stackid() */
call_get_func_ip:1, /* Do we call get_func_ip() */
- tstamp_type_access:1; /* Accessed __sk_buff->tstamp_type */
+ tstamp_type_access:1, /* Accessed __sk_buff->tstamp_type */
+ valid_id:1; /* Is bpf_prog::aux::__id valid? */
enum bpf_prog_type type; /* Type of BPF program */
enum bpf_attach_type expected_attach_type; /* For some prog types */
u32 len; /* Number of filter blocks */
@@ -1688,6 +1689,12 @@ void bpf_prog_inc(struct bpf_prog *prog);
struct bpf_prog * __must_check bpf_prog_inc_not_zero(struct bpf_prog *prog);
void bpf_prog_put(struct bpf_prog *prog);
+static inline u32 bpf_prog_get_id(const struct bpf_prog *prog)
+{
+ if (WARN(!prog->valid_id, "Attempting to use an invalid eBPF program"))
+ return 0;
+ return prog->aux->__id;
+}
void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock);
void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock);
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 9e1e6965f407..525c02cc12ea 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -604,7 +604,7 @@ static inline u64 bpf_trampoline_compute_key(const struct bpf_prog *tgt_prog,
struct btf *btf, u32 btf_id)
{
if (tgt_prog)
- return ((u64)tgt_prog->aux->id << 32) | btf_id;
+ return ((u64)bpf_prog_get_id(tgt_prog) << 32) | btf_id;
else
return ((u64)btf_obj_id(btf) << 32) | 0x80000000 | btf_id;
}
diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
index c40fc97f9417..a1c3048872ea 100644
--- a/include/trace/events/xdp.h
+++ b/include/trace/events/xdp.h
@@ -39,7 +39,7 @@ TRACE_EVENT(xdp_exception,
),
TP_fast_assign(
- __entry->prog_id = xdp->aux->id;
+ __entry->prog_id = (xdp->valid_id ? xdp->aux->__id : 0);
__entry->act = act;
__entry->ifindex = dev->ifindex;
),
@@ -120,7 +120,7 @@ DECLARE_EVENT_CLASS(xdp_redirect_template,
map_index = 0;
}
- __entry->prog_id = xdp->aux->id;
+ __entry->prog_id = (xdp->valid_id ? xdp->aux->__id : 0);
__entry->act = XDP_REDIRECT;
__entry->ifindex = dev->ifindex;
__entry->err = err;
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 832b2659e96e..d19db5980b1b 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -905,7 +905,7 @@ static void prog_fd_array_put_ptr(void *ptr)
static u32 prog_fd_array_sys_lookup_elem(void *ptr)
{
- return ((struct bpf_prog *)ptr)->aux->id;
+ return bpf_prog_get_id((struct bpf_prog *)ptr);
}
/* decrement refcnt of all bpf_progs that are stored in this map */
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index 84b2d9dba79a..6c20e6cd9442 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -488,7 +488,7 @@ static int bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
image += err;
/* put prog_id to udata */
- *(unsigned long *)(udata + moff) = prog->aux->id;
+ *(unsigned long *)(udata + moff) = bpf_prog_get_id(prog);
}
refcount_set(&kvalue->refcnt, 1);
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index bf2fdb33fb31..4a8d26f1d5d1 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -1091,7 +1091,7 @@ static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
i = 0;
hlist_for_each_entry(pl, progs, node) {
prog = prog_list_prog(pl);
- id = prog->aux->id;
+ id = bpf_prog_get_id(prog);
if (copy_to_user(prog_ids + i, &id, sizeof(id)))
return -EFAULT;
if (++i == cnt)
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 25a54e04560e..ea3938ab6f5b 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -2293,7 +2293,7 @@ static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
for (item = array->items; item->prog; item++) {
if (item->prog == &dummy_bpf_prog.prog)
continue;
- prog_ids[i] = item->prog->aux->id;
+ prog_ids[i] = bpf_prog_get_id(item->prog);
if (++i == request_cnt) {
item++;
break;
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index b5ba34ddd4b6..3f3423d03aea 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -413,7 +413,7 @@ static int __cpu_map_load_bpf_program(struct bpf_cpu_map_entry *rcpu,
return -EINVAL;
}
- rcpu->value.bpf_prog.id = prog->aux->id;
+ rcpu->value.bpf_prog.id = bpf_prog_get_id(prog);
rcpu->prog = prog;
return 0;
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index f9a87dcc5535..d46309d4aa9e 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -868,7 +868,7 @@ static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net,
dev->dtab = dtab;
if (prog) {
dev->xdp_prog = prog;
- dev->val.bpf_prog.id = prog->aux->id;
+ dev->val.bpf_prog.id = bpf_prog_get_id(prog);
} else {
dev->xdp_prog = NULL;
dev->val.bpf_prog.id = 0;
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 7b373a5e861f..9e862ef792cb 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1958,13 +1958,14 @@ static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
return;
if (audit_enabled == AUDIT_OFF)
return;
- if (op == BPF_AUDIT_LOAD)
+ if (!in_irq() && !irqs_disabled())
ctx = audit_context();
ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
if (unlikely(!ab))
return;
+ /* log the id regardless of bpf_prog::valid_id */
audit_log_format(ab, "prog-id=%u op=%s",
- prog->aux->id, bpf_audit_str[op]);
+ prog->aux->__id, bpf_audit_str[op]);
audit_log_end(ab);
}
@@ -1975,8 +1976,10 @@ static int bpf_prog_alloc_id(struct bpf_prog *prog)
idr_preload(GFP_KERNEL);
spin_lock_bh(&prog_idr_lock);
id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
- if (id > 0)
- prog->aux->id = id;
+ if (id > 0) {
+ prog->aux->__id = id;
+ prog->valid_id = true;
+ }
spin_unlock_bh(&prog_idr_lock);
idr_preload_end();
@@ -1996,7 +1999,7 @@ void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
* disappears - even if someone grabs an fd to them they are unusable,
* simply waiting for refcnt to drop to be freed.
*/
- if (!prog->aux->id)
+ if (!prog->valid_id)
return;
if (do_idr_lock)
@@ -2004,8 +2007,8 @@ void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
else
__acquire(&prog_idr_lock);
- idr_remove(&prog_idr, prog->aux->id);
- prog->aux->id = 0;
+ idr_remove(&prog_idr, prog->aux->__id);
+ prog->valid_id = false;
if (do_idr_lock)
spin_unlock_irqrestore(&prog_idr_lock, flags);
@@ -2154,7 +2157,7 @@ static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
prog->jited,
prog_tag,
prog->pages * 1ULL << PAGE_SHIFT,
- prog->aux->id,
+ bpf_prog_get_id(prog),
stats.nsecs,
stats.cnt,
stats.misses,
@@ -2786,7 +2789,7 @@ static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
bpf_link_type_strs[link->type],
link->id,
prog_tag,
- prog->aux->id);
+ bpf_prog_get_id(prog));
if (link->ops->show_fdinfo)
link->ops->show_fdinfo(link, m);
}
@@ -3914,7 +3917,7 @@ static int bpf_prog_get_info_by_fd(struct file *file,
return -EFAULT;
info.type = prog->type;
- info.id = prog->aux->id;
+ info.id = bpf_prog_get_id(prog);
info.load_time = prog->aux->load_time;
info.created_by_uid = from_kuid_munged(current_user_ns(),
prog->aux->user->uid);
@@ -4261,7 +4264,7 @@ static int bpf_link_get_info_by_fd(struct file *file,
info.type = link->type;
info.id = link->id;
- info.prog_id = link->prog->aux->id;
+ info.prog_id = bpf_prog_get_id(link->prog);
if (link->ops->fill_link_info) {
err = link->ops->fill_link_info(link, &info);
@@ -4426,7 +4429,7 @@ static int bpf_task_fd_query(const union bpf_attr *attr,
struct bpf_raw_event_map *btp = raw_tp->btp;
err = bpf_task_fd_query_copy(attr, uattr,
- raw_tp->link.prog->aux->id,
+ bpf_prog_get_id(raw_tp->link.prog),
BPF_FD_TYPE_RAW_TRACEPOINT,
btp->tp->name, 0, 0);
goto put_file;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index aefc1e08e015..c24e897d27f1 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9001,7 +9001,11 @@ void perf_event_bpf_event(struct bpf_prog *prog,
},
.type = type,
.flags = flags,
- .id = prog->aux->id,
+ /*
+ * don't use bpf_prog_get_id() as the id may be marked
+ * invalid on PERF_BPF_EVENT_PROG_UNLOAD events
+ */
+ .id = prog->aux->__id,
},
};
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 49fb9ec8366d..7cd0eb83b137 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2344,7 +2344,7 @@ int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
return -EOPNOTSUPP;
- *prog_id = prog->aux->id;
+ *prog_id = bpf_prog_get_id(prog);
flags = event->tp_event->flags;
is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
is_syscall_tp = is_syscall_trace_event(event->tp_event);
diff --git a/net/core/dev.c b/net/core/dev.c
index fa53830d0683..0d39ef22cf4b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9068,7 +9068,7 @@ u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
{
struct bpf_prog *prog = dev_xdp_prog(dev, mode);
- return prog ? prog->aux->id : 0;
+ return prog ? bpf_prog_get_id(prog) : 0;
}
static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
diff --git a/net/core/filter.c b/net/core/filter.c
index bb0136e7a8e4..282ccfe34ced 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -8729,7 +8729,8 @@ void bpf_warn_invalid_xdp_action(struct net_device *dev, struct bpf_prog *prog,
pr_warn_once("%s XDP return value %u on prog %s (id %d) dev %s, expect packet loss!\n",
act > act_max ? "Illegal" : "Driver unsupported",
- act, prog->aux->name, prog->aux->id, dev ? dev->name : "N/A");
+ act, prog->aux->name, bpf_prog_get_id(prog),
+ dev ? dev->name : "N/A");
}
EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 74864dc46a7e..1f7e36909541 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1453,7 +1453,7 @@ static u32 rtnl_xdp_prog_skb(struct net_device *dev)
generic_xdp_prog = rtnl_dereference(dev->xdp_prog);
if (!generic_xdp_prog)
return 0;
- return generic_xdp_prog->aux->id;
+ return bpf_prog_get_id(generic_xdp_prog);
}
static u32 rtnl_xdp_prog_drv(struct net_device *dev)
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index a660baedd9e7..550ec6cb3aee 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -1518,7 +1518,7 @@ int sock_map_bpf_prog_query(const union bpf_attr *attr,
/* we do not hold the refcnt, the bpf prog may be released
* asynchronously and the id would be set to 0.
*/
- id = data_race(prog->aux->id);
+ id = data_race(bpf_prog_get_id(prog));
if (id == 0)
prog_cnt = 0;
diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c
index 8370726ae7bf..440ce3aba802 100644
--- a/net/ipv6/seg6_local.c
+++ b/net/ipv6/seg6_local.c
@@ -1543,7 +1543,8 @@ static int put_nla_bpf(struct sk_buff *skb, struct seg6_local_lwt *slwt)
if (!nest)
return -EMSGSIZE;
- if (nla_put_u32(skb, SEG6_LOCAL_BPF_PROG, slwt->bpf.prog->aux->id))
+ if (nla_put_u32(skb, SEG6_LOCAL_BPF_PROG,
+ bpf_prog_get_id(slwt->bpf.prog)))
return -EMSGSIZE;
if (slwt->bpf.name &&
diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c
index b79eee44e24e..604a29e482b0 100644
--- a/net/sched/act_bpf.c
+++ b/net/sched/act_bpf.c
@@ -121,7 +121,7 @@ static int tcf_bpf_dump_ebpf_info(const struct tcf_bpf *prog,
nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name))
return -EMSGSIZE;
- if (nla_put_u32(skb, TCA_ACT_BPF_ID, prog->filter->aux->id))
+ if (nla_put_u32(skb, TCA_ACT_BPF_ID, bpf_prog_get_id(prog->filter)))
return -EMSGSIZE;
nla = nla_reserve(skb, TCA_ACT_BPF_TAG, sizeof(prog->filter->tag));
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index bc317b3eac12..eb5ac6be589e 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -565,7 +565,7 @@ static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
return -EMSGSIZE;
- if (nla_put_u32(skb, TCA_BPF_ID, prog->filter->aux->id))
+ if (nla_put_u32(skb, TCA_BPF_ID, bpf_prog_get_id(prog->filter)))
return -EMSGSIZE;
nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
--
2.39.0
1 year, 4 months
- 7
- 17
[PATCH] bpf: restore the ebpf audit UNLOAD id field
by Paul Moore
When changing the ebpf program put() routines to support being called
from within IRQ context the program ID was reset to zero prior to
generating the audit UNLOAD record, which obviously rendered the ID
field bogus (always zero). This patch resolves this by adding a new
field, bpf_prog_aux::id_audit, which is set when the ebpf program is
allocated an ID and never reset, ensuring a valid ID field,
regardless of the state of the original ID field, bpf_prox_aud::id.
I also modified the bpf_audit_prog() logic used to associate the
AUDIT_BPF record with other associated records, e.g. @ctx != NULL.
Instead of keying off the operation, it now keys off the execution
context, e.g. '!in_irg && !irqs_disabled()', which is much more
appropriate and should help better connect the UNLOAD operations with
the associated audit state (other audit records).
As an note to future bug hunters, I did briefly consider removing the
ID reset in bpf_prog_free_id(), as it would seem that once the
program is removed from the idr pool it can no longer be found by its
ID value, but commit ad8ad79f4f60 ("bpf: offload: free program id
when device disappears") seems to imply that it is beneficial to
reset the ID value. Perhaps as a secondary indicator that the ebpf
program is unbound/orphaned.
Fixes: d809e134be7a ("bpf: Prepare bpf_prog_put() to be called from irq context.")
Reported-by: Burn Alting <burn.alting(a)iinet.net.au>
Signed-off-by: Paul Moore <paul(a)paul-moore.com>
---
include/linux/bpf.h | 1 +
kernel/bpf/syscall.c | 8 +++++---
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 9e7d46d16032..a22001ceb2c3 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1103,6 +1103,7 @@ struct bpf_prog_aux {
u32 max_tp_access;
u32 stack_depth;
u32 id;
+ u32 id_audit; /* preserves the id for use by audit */
u32 func_cnt; /* used by non-func prog as the number of func progs */
u32 func_idx; /* 0 for non-func prog, the index in func array for func prog */
u32 attach_btf_id; /* in-kernel BTF type id to attach to */
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 7b373a5e861f..3ec09f4dba18 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1958,13 +1958,13 @@ static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
return;
if (audit_enabled == AUDIT_OFF)
return;
- if (op == BPF_AUDIT_LOAD)
+ if (!in_irq() && !irqs_disabled())
ctx = audit_context();
ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
if (unlikely(!ab))
return;
audit_log_format(ab, "prog-id=%u op=%s",
- prog->aux->id, bpf_audit_str[op]);
+ prog->aux->id_audit, bpf_audit_str[op]);
audit_log_end(ab);
}
@@ -1975,8 +1975,10 @@ static int bpf_prog_alloc_id(struct bpf_prog *prog)
idr_preload(GFP_KERNEL);
spin_lock_bh(&prog_idr_lock);
id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
- if (id > 0)
+ if (id > 0) {
prog->aux->id = id;
+ prog->aux->id_audit = id;
+ }
spin_unlock_bh(&prog_idr_lock);
idr_preload_end();
--
2.39.0
1 year, 4 months
- 4
- 11
BPF audit logs
by Burn Alting
Hi,
I note that the unsolicited AUDIT_BPF audit event only provides a program id and
operation (load or unload). For example, type=BPF msg=audit(21/12/22
09:03:35.765:439) : prog-id=75 op=LOAD or type=BPF msg=audit(21/12/22
09:04:05.883:460) : prog-id=0 op=UNLOAD
I also note that the bpf auxillary structure (struct bpf_prog_aux) that holds the
program id value, also holds a name (struct bpf_prog_aux->name) and uid (struct
bpf_prog_aud->user_struct->uid). Perhaps adding these two items to the AUDIT_BPF
event would provide more security context for this unsolicited event.
Thoughts?
RgdsBurn Alting
1 year, 4 months
- 4
- 7
[PATCH 0/2] Provide matching audit timestamp in the SELinux AVC trace event
by Ondrej Mosnacek
This series allows to match the SELinux AVC trace events to the
corresponding audit events via the audit event timestamp. This
will help with troubleshooting SELinux denials.
Ondrej Mosnacek (2):
audit: introduce a struct to represent an audit timestamp
selinux: provide matching audit timestamp in the AVC trace event
include/linux/audit.h | 13 +++++++++++++
include/trace/events/avc.h | 25 +++++++++++++++++--------
kernel/audit.c | 23 +++++++++++++++--------
kernel/audit.h | 4 ++--
kernel/auditsc.c | 9 ++++-----
security/selinux/avc.c | 4 +++-
6 files changed, 54 insertions(+), 24 deletions(-)
--
2.38.1
1 year, 4 months
- 3
- 3
[PATCH RESEND 0/2] Provide matching audit timestamp in the SELinux AVC trace event
by Ondrej Mosnacek
(Resending due to an error on the first attempt.)
This series allows to match the SELinux AVC trace events to the
corresponding audit events via the audit event timestamp. This
will help with troubleshooting SELinux denials.
Ondrej Mosnacek (2):
audit: introduce a struct to represent an audit timestamp
selinux: provide matching audit timestamp in the AVC trace event
include/linux/audit.h | 13 +++++++++++++
include/trace/events/avc.h | 25 +++++++++++++++++--------
kernel/audit.c | 23 +++++++++++++++--------
kernel/audit.h | 4 ++--
kernel/auditsc.c | 9 ++++-----
security/selinux/avc.c | 4 +++-
6 files changed, 54 insertions(+), 24 deletions(-)
--
2.38.1
1 year, 4 months
- 2
- 3
[GIT PULL] Audit patches for v6.2
by Paul Moore
Hi Linus,
Two performance oriented patches for the audit subsystem: one
consolidates similar code to gain some caching advantages, while the
other stores a value in a stack variable to avoid repeated lookups in
a loop. The commit descriptions have more information, including some
before/after performance measurements. Please merge for v6.2.
-Paul
--
The following changes since commit 9abf2313adc1ca1b6180c508c25f22f9395cc780:
Linux 6.1-rc1 (2022-10-16 15:36:24 -0700)
are available in the Git repository at:
https://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit.git
tags/audit-pr-20221212
for you to fetch changes up to 50979953c0c41e929e5f955800da68e1bb24c7ab:
audit: unify audit_filter_{uring(), inode_name(), syscall()}
(2022-10-17 14:24:42 -0400)
----------------------------------------------------------------
audit/stable-6.2 PR 20221212
----------------------------------------------------------------
Ankur Arora (2):
audit: cache ctx->major in audit_filter_syscall()
audit: unify audit_filter_{uring(), inode_name(), syscall()}
kernel/auditsc.c | 75 ++++++++++++++++++++++++++------------------------
1 file changed, 39 insertions(+), 36 deletions(-)
--
paul-moore.com
1 year, 5 months
- 2
- 1
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