| Age | Commit message (Collapse) | Author |
|---|
|
Replace the (secctx,seclen) pointer pair with a single lsm_context
pointer to allow return of the LSM identifier along with the context
and context length. This allows security_release_secctx() to know how
to release the context. Callers have been modified to use or save the
returned data from the new structure.
Cc: ceph-devel@vger.kernel.org
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Change the security_inode_getsecctx() interface to fill a lsm_context
structure instead of data and length pointers. This provides
the information about which LSM created the context so that
security_release_secctx() can use the correct hook.
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Replace the (secctx,seclen) pointer pair with a single
lsm_context pointer to allow return of the LSM identifier
along with the context and context length. This allows
security_release_secctx() to know how to release the
context. Callers have been modified to use or save the
returned data from the new structure.
security_secid_to_secctx() and security_lsmproc_to_secctx()
will now return the length value on success instead of 0.
Cc: netdev@vger.kernel.org
Cc: audit@vger.kernel.org
Cc: netfilter-devel@vger.kernel.org
Cc: Todd Kjos <tkjos@google.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject tweak, kdoc fix, signedness fix from Dan Carpenter]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Add a new lsm_context data structure to hold all the information about a
"security context", including the string, its size and which LSM allocated
the string. The allocation information is necessary because LSMs have
different policies regarding the lifecycle of these strings. SELinux
allocates and destroys them on each use, whereas Smack provides a pointer
to an entry in a list that never goes away.
Update security_release_secctx() to use the lsm_context instead of a
(char *, len) pair. Change its callers to do likewise. The LSMs
supporting this hook have had comments added to remind the developer
that there is more work to be done.
The BPF security module provides all LSM hooks. While there has yet to
be a known instance of a BPF configuration that uses security contexts,
the possibility is real. In the existing implementation there is
potential for multiple frees in that case.
Cc: linux-integrity@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: audit@vger.kernel.org
Cc: netfilter-devel@vger.kernel.org
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: linux-nfs@vger.kernel.org
Cc: Todd Kjos <tkjos@google.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull lsm updates from Paul Moore:
"Thirteen patches, all focused on moving away from the current 'secid'
LSM identifier to a richer 'lsm_prop' structure.
This move will help reduce the translation that is necessary in many
LSMs, offering better performance, and make it easier to support
different LSMs in the future"
* tag 'lsm-pr-20241112' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
lsm: remove lsm_prop scaffolding
netlabel,smack: use lsm_prop for audit data
audit: change context data from secid to lsm_prop
lsm: create new security_cred_getlsmprop LSM hook
audit: use an lsm_prop in audit_names
lsm: use lsm_prop in security_inode_getsecid
lsm: use lsm_prop in security_current_getsecid
audit: update shutdown LSM data
lsm: use lsm_prop in security_ipc_getsecid
audit: maintain an lsm_prop in audit_context
lsm: add lsmprop_to_secctx hook
lsm: use lsm_prop in security_audit_rule_match
lsm: add the lsm_prop data structure
|
|
Remove the scaffold member from the lsm_prop. Remove the
remaining places it is being set.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subj line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Create a new LSM hook security_cred_getlsmprop() which, like
security_cred_getsecid(), fetches LSM specific attributes from the
cred structure. The associated data elements in the audit sub-system
are changed from a secid to a lsm_prop to accommodate multiple possible
LSM audit users.
Cc: linux-integrity@vger.kernel.org
Cc: audit@vger.kernel.org
Cc: selinux@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subj line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Change the security_inode_getsecid() interface to fill in a
lsm_prop structure instead of a u32 secid. This allows for its
callers to gather data from all registered LSMs. Data is provided
for IMA and audit. Change the name to security_inode_getlsmprop().
Cc: linux-integrity@vger.kernel.org
Cc: selinux@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subj line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Change the security_current_getsecid_subj() and
security_task_getsecid_obj() interfaces to fill in a lsm_prop structure
instead of a u32 secid. Audit interfaces will need to collect all
possible security data for possible reporting.
Cc: linux-integrity@vger.kernel.org
Cc: audit@vger.kernel.org
Cc: selinux@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
There may be more than one LSM that provides IPC data for auditing.
Change security_ipc_getsecid() to fill in a lsm_prop structure instead
of the u32 secid. Change the name to security_ipc_getlsmprop() to
reflect the change.
Cc: audit@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Replace the secid value stored in struct audit_context with a struct
lsm_prop. Change the code that uses this value to accommodate the
change. security_audit_rule_match() expects a lsm_prop, so existing
scaffolding can be removed. A call to security_secid_to_secctx()
is changed to security_lsmprop_to_secctx(). The call to
security_ipc_getsecid() is scaffolded.
A new function lsmprop_is_set() is introduced to identify whether
an lsm_prop contains a non-zero value.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject line tweak, fix lsmprop_is_set() typo]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Add a new hook security_lsmprop_to_secctx() and its LSM specific
implementations. The LSM specific code will use the lsm_prop element
allocated for that module. This allows for the possibility that more
than one module may be called upon to translate a secid to a string,
as can occur in the audit code.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Change the secid parameter of security_audit_rule_match
to a lsm_prop structure pointer. Pass the entry from the
lsm_prop structure for the approprite slot to the LSM hook.
Change the users of security_audit_rule_match to use the
lsm_prop instead of a u32. The scaffolding function lsmprop_init()
fills the structure with the value of the old secid, ensuring that
it is available to the appropriate module hook. The sources of
the secid, security_task_getsecid() and security_inode_getsecid(),
will be converted to use the lsm_prop structure later in the series.
At that point the use of lsmprop_init() is dropped.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
When more than one security module is exporting data to audit and
networking sub-systems a single 32 bit integer is no longer
sufficient to represent the data. Add a structure to be used instead.
The lsm_prop structure definition is intended to keep the LSM
specific information private to the individual security modules.
The module specific information is included in a new set of
header files under include/lsm. Each security module is allowed
to define the information included for its use in the lsm_prop.
SELinux includes a u32 secid. Smack includes a pointer into its
global label list. The conditional compilation based on feature
inclusion is contained in the include/lsm files.
Cc: apparmor@lists.ubuntu.com
Cc: bpf@vger.kernel.org
Cc: selinux@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Suggested-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
[PM: added include/linux/lsm/ to MAINTAINERS, subj tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Patch series "remove PF_MEMALLOC_NORECLAIM" v3.
This patch (of 2):
bch2_new_inode relies on PF_MEMALLOC_NORECLAIM to try to allocate a new
inode to achieve GFP_NOWAIT semantic while holding locks. If this
allocation fails it will drop locks and use GFP_NOFS allocation context.
We would like to drop PF_MEMALLOC_NORECLAIM because it is really
dangerous to use if the caller doesn't control the full call chain with
this flag set. E.g. if any of the function down the chain needed
GFP_NOFAIL request the PF_MEMALLOC_NORECLAIM would override this and
cause unexpected failure.
While this is not the case in this particular case using the scoped gfp
semantic is not really needed bacause we can easily pus the allocation
context down the chain without too much clutter.
[akpm@linux-foundation.org: fix kerneldoc warnings]
Link: https://lkml.kernel.org/r/20240926172940.167084-1-mhocko@kernel.org
Link: https://lkml.kernel.org/r/20240926172940.167084-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz> # For vfs changes
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: James Morris <jmorris@namei.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Serge E. Hallyn <serge@hallyn.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf 'struct fd' updates from Alexei Starovoitov:
"This includes struct_fd BPF changes from Al and Andrii"
* tag 'bpf-next-6.12-struct-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
bpf: convert bpf_token_create() to CLASS(fd, ...)
security,bpf: constify struct path in bpf_token_create() LSM hook
bpf: more trivial fdget() conversions
bpf: trivial conversions for fdget()
bpf: switch maps to CLASS(fd, ...)
bpf: factor out fetching bpf_map from FD and adding it to used_maps list
bpf: switch fdget_raw() uses to CLASS(fd_raw, ...)
bpf: convert __bpf_prog_get() to CLASS(fd, ...)
|
|
There is no reason why struct path pointer shouldn't be const-qualified
when being passed into bpf_token_create() LSM hook. Add that const.
Acked-by: Paul Moore <paul@paul-moore.com> (LSM/SELinux)
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
|
|
This patch enhances fsverity's capabilities to support both integrity and
authenticity protection by introducing the exposure of built-in
signatures through a new LSM hook. This functionality allows LSMs,
e.g. IPE, to enforce policies based on the authenticity and integrity of
files, specifically focusing on built-in fsverity signatures. It enables
a policy enforcement layer within LSMs for fsverity, offering granular
control over the usage of authenticity claims. For instance, a policy
could be established to only permit the execution of all files with
verified built-in fsverity signatures.
The introduction of a security_inode_setintegrity() hook call within
fsverity's workflow ensures that the verified built-in signature of a file
is exposed to LSMs. This enables LSMs to recognize and label fsverity files
that contain a verified built-in fsverity signature. This hook is invoked
subsequent to the fsverity_verify_signature() process, guaranteeing the
signature's verification against fsverity's keyring. This mechanism is
crucial for maintaining system security, as it operates in kernel space,
effectively thwarting attempts by malicious binaries to bypass user space
stack interactions.
The second to last commit in this patch set will add a link to the IPE
documentation in fsverity.rst.
Signed-off-by: Deven Bowers <deven.desai@linux.microsoft.com>
Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
This patch introduces a new hook to save inode's integrity
data. For example, for fsverity enabled files, LSMs can use this hook to
save the existence of verified fsverity builtin signature into the inode's
security blob, and LSMs can make access decisions based on this data.
Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
[PM: subject line tweak, removed changelog]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
dm-verity provides a strong guarantee of a block device's integrity. As
a generic way to check the integrity of a block device, it provides
those integrity guarantees to its higher layers, including the filesystem
level.
However, critical security metadata like the dm-verity roothash and its
signing information are not easily accessible to the LSMs.
To address this limitation, this patch introduces a mechanism to store
and manage these essential security details within a newly added LSM blob
in the block_device structure.
This addition allows LSMs to make access control decisions on the integrity
data stored within the block_device, enabling more flexible security
policies. For instance, LSMs can now revoke access to dm-verity devices
based on their roothashes, ensuring that only authorized and verified
content is accessible. Additionally, LSMs can enforce policies to only
allow files from dm-verity devices that have a valid digital signature to
execute, effectively blocking any unsigned files from execution, thus
enhancing security against unauthorized modifications.
The patch includes new hook calls, `security_bdev_setintegrity()`, in
dm-verity to expose the dm-verity roothash and the roothash signature to
LSMs via preresume() callback. By using the preresume() callback, it
ensures that the security metadata is consistently in sync with the
metadata of the dm-verity target in the current active mapping table.
The hook calls are depended on CONFIG_SECURITY.
Signed-off-by: Deven Bowers <deven.desai@linux.microsoft.com>
Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
[PM: moved sig_size field as discussed]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
This patch introduces a new LSM blob to the block_device structure,
enabling the security subsystem to store security-sensitive data related
to block devices. Currently, for a device mapper's mapped device containing
a dm-verity target, critical security information such as the roothash and
its signing state are not readily accessible. Specifically, while the
dm-verity volume creation process passes the dm-verity roothash and its
signature from userspace to the kernel, the roothash is stored privately
within the dm-verity target, and its signature is discarded
post-verification. This makes it extremely hard for the security subsystem
to utilize these data.
With the addition of the LSM blob to the block_device structure, the
security subsystem can now retain and manage important security metadata
such as the roothash and the signing state of a dm-verity by storing them
inside the blob. Access decisions can then be based on these stored data.
The implementation follows the same approach used for security blobs in
other structures like struct file, struct inode, and struct superblock.
The initialization of the security blob occurs after the creation of the
struct block_device, performed by the security subsystem. Similarly, the
security blob is freed by the security subsystem before the struct
block_device is deallocated or freed.
This patch also introduces a new hook security_bdev_setintegrity() to save
block device's integrity data to the new LSM blob. For example, for
dm-verity, it can use this hook to expose its roothash and signing state
to LSMs, then LSMs can save these data into the LSM blob.
Please note that the new hook should be invoked every time the security
information is updated to keep these data current. For example, in
dm-verity, if the mapping table is reloaded and configured to use a
different dm-verity target with a new roothash and signing information,
the previously stored data in the LSM blob will become obsolete. It is
crucial to re-invoke the hook to refresh these data and ensure they are up
to date. This necessity arises from the design of device-mapper, where a
device-mapper device is first created, and then targets are subsequently
loaded into it. These targets can be modified multiple times during the
device's lifetime. Therefore, while the LSM blob is allocated during the
creation of the block device, its actual contents are not initialized at
this stage and can change substantially over time. This includes
alterations from data that the LSM 'trusts' to those it does not, making
it essential to handle these changes correctly. Failure to address this
dynamic aspect could potentially allow for bypassing LSM checks.
Signed-off-by: Deven Bowers <deven.desai@linux.microsoft.com>
Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
[PM: merge fuzz, subject line tweaks]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
When deleting a directory in the security file system, the existing
securityfs_remove requires the directory to be empty, otherwise
it will do nothing. This leads to a potential risk that the security
file system might be in an unclean state when the intended deletion
did not happen.
This commit introduces a new function securityfs_recursive_remove
to recursively delete a directory without leaving an unclean state.
Co-developed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
This patch introduces a new hook to notify security system that the
content of initramfs has been unpacked into the rootfs.
Upon receiving this notification, the security system can activate
a policy to allow only files that originated from the initramfs to
execute or load into kernel during the early stages of booting.
This approach is crucial for minimizing the attack surface by
ensuring that only trusted files from the initramfs are operational
in the critical boot phase.
Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
To be consistent with most LSM hooks, convert the return value of
hook vm_enough_memory to 0 or a negative error code.
Before:
- Hook vm_enough_memory returns 1 if permission is granted, 0 if not.
- LSM_RET_DEFAULT(vm_enough_memory_mm) is 1.
After:
- Hook vm_enough_memory reutrns 0 if permission is granted, negative
error code if not.
- LSM_RET_DEFAULT(vm_enough_memory_mm) is 0.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.
This patch has been generated by the following coccinelle script:
```
virtual patch
@r1@
identifier ctl, write, buffer, lenp, ppos;
identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
@@
int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int write, void *buffer, size_t *lenp, loff_t *ppos);
@r2@
identifier func, ctl, write, buffer, lenp, ppos;
@@
int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int write, void *buffer, size_t *lenp, loff_t *ppos)
{ ... }
@r3@
identifier func;
@@
int func(
- struct ctl_table *
+ const struct ctl_table *
,int , void *, size_t *, loff_t *);
@r4@
identifier func, ctl;
@@
int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int , void *, size_t *, loff_t *);
@r5@
identifier func, write, buffer, lenp, ppos;
@@
int func(
- struct ctl_table *
+ const struct ctl_table *
,int write, void *buffer, size_t *lenp, loff_t *ppos);
```
* Code formatting was adjusted in xfs_sysctl.c to comply with code
conventions. The xfs_stats_clear_proc_handler,
xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
adjusted.
* The ctl_table argument in proc_watchdog_common was const qualified.
This is called from a proc_handler itself and is calling back into
another proc_handler, making it necessary to change it as part of the
proc_handler migration.
Co-developed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Co-developed-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Joel Granados <j.granados@samsung.com>
|
|
A panic happens in ima_match_policy:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
PGD 42f873067 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 5 PID: 1286325 Comm: kubeletmonit.sh
Kdump: loaded Tainted: P
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 0.0.0 02/06/2015
RIP: 0010:ima_match_policy+0x84/0x450
Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39
7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d
f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea
44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f
RSP: 0018:ff71570009e07a80 EFLAGS: 00010207
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200
RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739
R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970
R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001
FS: 00007f5195b51740(0000)
GS:ff3e278b12d40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ima_get_action+0x22/0x30
process_measurement+0xb0/0x830
? page_add_file_rmap+0x15/0x170
? alloc_set_pte+0x269/0x4c0
? prep_new_page+0x81/0x140
? simple_xattr_get+0x75/0xa0
? selinux_file_open+0x9d/0xf0
ima_file_check+0x64/0x90
path_openat+0x571/0x1720
do_filp_open+0x9b/0x110
? page_counter_try_charge+0x57/0xc0
? files_cgroup_alloc_fd+0x38/0x60
? __alloc_fd+0xd4/0x250
? do_sys_open+0x1bd/0x250
do_sys_open+0x1bd/0x250
do_syscall_64+0x5d/0x1d0
entry_SYSCALL_64_after_hwframe+0x65/0xca
Commit c7423dbdbc9e ("ima: Handle -ESTALE returned by
ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a
RCU read-side critical section which contains kmalloc with GFP_KERNEL.
This implies a possible sleep and violates limitations of RCU read-side
critical sections on non-PREEMPT systems.
Sleeping within RCU read-side critical section might cause
synchronize_rcu() returning early and break RCU protection, allowing a
UAF to happen.
The root cause of this issue could be described as follows:
| Thread A | Thread B |
| |ima_match_policy |
| | rcu_read_lock |
|ima_lsm_update_rule | |
| synchronize_rcu | |
| | kmalloc(GFP_KERNEL)|
| | sleep |
==> synchronize_rcu returns early
| kfree(entry) | |
| | entry = entry->next|
==> UAF happens and entry now becomes NULL (or could be anything).
| | entry->action |
==> Accessing entry might cause panic.
To fix this issue, we are converting all kmalloc that is called within
RCU read-side critical section to use GFP_ATOMIC.
Fixes: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()")
Cc: stable@vger.kernel.org
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Copying up xattrs is solely based on the security xattr name. For finer
granularity add a dentry parameter to the security_inode_copy_up_xattr
hook definition, allowing decisions to be based on the xattr content as
well.
Co-developed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Paul Moore <paul@paul-moore.com> (LSM,SELinux)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
|
|
Change the size parameters in lsm_list_modules(), lsm_set_self_attr()
and lsm_get_self_attr() from size_t to u32. This avoids the need to
have different interfaces for 32 and 64 bit systems.
Cc: stable@vger.kernel.org
Fixes: a04a1198088a ("LSM: syscalls for current process attributes")
Fixes: ad4aff9ec25f ("LSM: Create lsm_list_modules system call")
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reported-and-reviewed-by: Dmitry V. Levin <ldv@strace.io>
[PM: subject and metadata tweaks, syscall.h fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull lsm updates from Paul Moore:
- Promote IMA/EVM to a proper LSM
This is the bulk of the diffstat, and the source of all the changes
in the VFS code. Prior to the start of the LSM stacking work it was
important that IMA/EVM were separate from the rest of the LSMs,
complete with their own hooks, infrastructure, etc. as it was the
only way to enable IMA/EVM at the same time as a LSM.
However, now that the bulk of the LSM infrastructure supports
multiple simultaneous LSMs, we can simplify things greatly by
bringing IMA/EVM into the LSM infrastructure as proper LSMs. This is
something I've wanted to see happen for quite some time and Roberto
was kind enough to put in the work to make it happen.
- Use the LSM hook default values to simplify the call_int_hook() macro
Previously the call_int_hook() macro required callers to supply a
default return value, despite a default value being specified when
the LSM hook was defined.
This simplifies the macro by using the defined default return value
which makes life easier for callers and should also reduce the number
of return value bugs in the future (we've had a few pop up recently,
hence this work).
- Use the KMEM_CACHE() macro instead of kmem_cache_create()
The guidance appears to be to use the KMEM_CACHE() macro when
possible and there is no reason why we can't use the macro, so let's
use it.
- Fix a number of comment typos in the LSM hook comment blocks
Not much to say here, we fixed some questionable grammar decisions in
the LSM hook comment blocks.
* tag 'lsm-pr-20240312' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (28 commits)
cred: Use KMEM_CACHE() instead of kmem_cache_create()
lsm: use default hook return value in call_int_hook()
lsm: fix typos in security/security.c comment headers
integrity: Remove LSM
ima: Make it independent from 'integrity' LSM
evm: Make it independent from 'integrity' LSM
evm: Move to LSM infrastructure
ima: Move IMA-Appraisal to LSM infrastructure
ima: Move to LSM infrastructure
integrity: Move integrity_kernel_module_request() to IMA
security: Introduce key_post_create_or_update hook
security: Introduce inode_post_remove_acl hook
security: Introduce inode_post_set_acl hook
security: Introduce inode_post_create_tmpfile hook
security: Introduce path_post_mknod hook
security: Introduce file_release hook
security: Introduce file_post_open hook
security: Introduce inode_post_removexattr hook
security: Introduce inode_post_setattr hook
security: Align inode_setattr hook definition with EVM
...
|
|
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the key_post_create_or_update hook.
Depending on policy, IMA measures the key content after creation or update,
so that remote verifiers are aware of the operation.
Other LSMs could similarly take some action after successful key creation
or update.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_remove_acl hook.
At inode_remove_acl hook, EVM verifies the file's existing HMAC value. At
inode_post_remove_acl, EVM re-calculates the file's HMAC with the passed
POSIX ACL removed and other file metadata.
Other LSMs could similarly take some action after successful POSIX ACL
removal.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_set_acl hook.
At inode_set_acl hook, EVM verifies the file's existing HMAC value. At
inode_post_set_acl, EVM re-calculates the file's HMAC based on the modified
POSIX ACL and other file metadata.
Other LSMs could similarly take some action after successful POSIX ACL
change.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_create_tmpfile hook.
As temp files can be made persistent, treat new temp files like other new
files, so that the file hash is calculated and stored in the security
xattr.
LSMs could also take some action after temp files have been created.
The new hook cannot return an error and cannot cause the operation to be
canceled.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the path_post_mknod hook.
IMA-appraisal requires all existing files in policy to have a file
hash/signature stored in security.ima. An exception is made for empty files
created by mknod, by tagging them as new files.
LSMs could also take some action after files are created.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the file_release hook.
IMA calculates at file close the new digest of the file content and writes
it to security.ima, so that appraisal at next file access succeeds.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation to move IMA and EVM to the LSM infrastructure, introduce the
file_post_open hook. Also, export security_file_post_open() for NFS.
Based on policy, IMA calculates the digest of the file content and
extends the TPM with the digest, verifies the file's integrity based on
the digest, and/or includes the file digest in the audit log.
LSMs could similarly take action depending on the file content and the
access mask requested with open().
The new hook returns a value and can cause the open to be aborted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_removexattr hook.
At inode_removexattr hook, EVM verifies the file's existing HMAC value. At
inode_post_removexattr, EVM re-calculates the file's HMAC with the passed
xattr removed and other file metadata.
Other LSMs could similarly take some action after successful xattr removal.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_setattr hook.
At inode_setattr hook, EVM verifies the file's existing HMAC value. At
inode_post_setattr, EVM re-calculates the file's HMAC based on the modified
file attributes and other file metadata.
Other LSMs could similarly take some action after successful file attribute
change.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Wire up bpf_token_create and bpf_token_free LSM hooks, which allow to
allocate LSM security blob (we add `void *security` field to struct
bpf_token for that), but also control who can instantiate BPF token.
This follows existing pattern for BPF map and BPF prog.
Also add security_bpf_token_allow_cmd() and security_bpf_token_capable()
LSM hooks that allow LSM implementation to control and negate (if
necessary) BPF token's delegation of a specific bpf_cmd and capability,
respectively.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-12-andrii@kernel.org
|
|
Similarly to bpf_prog_alloc LSM hook, rename and extend bpf_map_alloc
hook into bpf_map_create, taking not just struct bpf_map, but also
bpf_attr and bpf_token, to give a fuller context to LSMs.
Unlike bpf_prog_alloc, there is no need to move the hook around, as it
currently is firing right before allocating BPF map ID and FD, which
seems to be a sweet spot.
But like bpf_prog_alloc/bpf_prog_free combo, make sure that bpf_map_free
LSM hook is called even if bpf_map_create hook returned error, as if few
LSMs are combined together it could be that one LSM successfully
allocated security blob for its needs, while subsequent LSM rejected BPF
map creation. The former LSM would still need to free up LSM blob, so we
need to ensure security_bpf_map_free() is called regardless of the
outcome.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-11-andrii@kernel.org
|
|
Based on upstream discussion ([0]), rework existing
bpf_prog_alloc_security LSM hook. Rename it to bpf_prog_load and instead
of passing bpf_prog_aux, pass proper bpf_prog pointer for a full BPF
program struct. Also, we pass bpf_attr union with all the user-provided
arguments for BPF_PROG_LOAD command. This will give LSMs as much
information as we can basically provide.
The hook is also BPF token-aware now, and optional bpf_token struct is
passed as a third argument. bpf_prog_load LSM hook is called after
a bunch of sanity checks were performed, bpf_prog and bpf_prog_aux were
allocated and filled out, but right before performing full-fledged BPF
verification step.
bpf_prog_free LSM hook is now accepting struct bpf_prog argument, for
consistency. SELinux code is adjusted to all new names, types, and
signatures.
Note, given that bpf_prog_load (previously bpf_prog_alloc) hook can be
used by some LSMs to allocate extra security blob, but also by other
LSMs to reject BPF program loading, we need to make sure that
bpf_prog_free LSM hook is called after bpf_prog_load/bpf_prog_alloc one
*even* if the hook itself returned error. If we don't do that, we run
the risk of leaking memory. This seems to be possible today when
combining SELinux and BPF LSM, as one example, depending on their
relative ordering.
Also, for BPF LSM setup, add bpf_prog_load and bpf_prog_free to
sleepable LSM hooks list, as they are both executed in sleepable
context. Also drop bpf_prog_load hook from untrusted, as there is no
issue with refcount or anything else anymore, that originally forced us
to add it to untrusted list in c0c852dd1876 ("bpf: Do not mark certain LSM
hook arguments as trusted"). We now trigger this hook much later and it
should not be an issue anymore.
[0] https://lore.kernel.org/bpf/9fe88aef7deabbe87d3fc38c4aea3c69.paul@paul-moore.com/
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-10-andrii@kernel.org
|
|
Some ioctl commands do not require ioctl permission, but are routed to
other permissions such as FILE_GETATTR or FILE_SETATTR. This routing is
done by comparing the ioctl cmd to a set of 64-bit flags (FS_IOC_*).
However, if a 32-bit process is running on a 64-bit kernel, it emits
32-bit flags (FS_IOC32_*) for certain ioctl operations. These flags are
being checked erroneously, which leads to these ioctl operations being
routed to the ioctl permission, rather than the correct file
permissions.
This was also noted in a RED-PEN finding from a while back -
"/* RED-PEN how should LSM module know it's handling 32bit? */".
This patch introduces a new hook, security_file_ioctl_compat(), that is
called from the compat ioctl syscall. All current LSMs have been changed
to support this hook.
Reviewing the three places where we are currently using
security_file_ioctl(), it appears that only SELinux needs a dedicated
compat change; TOMOYO and SMACK appear to be functional without any
change.
Cc: stable@vger.kernel.org
Fixes: 0b24dcb7f2f7 ("Revert "selinux: simplify ioctl checking"")
Signed-off-by: Alfred Piccioni <alpic@google.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: subject tweak, line length fixes, and alignment corrections]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
While we have a lsm_fill_user_ctx() helper function designed to make
life easier for LSMs which return lsm_ctx structs to userspace, we
didn't include all of the buffer length safety checks and buffer
padding adjustments in the helper. This led to code duplication
across the different LSMs and the possibility for mistakes across the
different LSM subsystems. In order to reduce code duplication and
decrease the chances of silly mistakes, we're consolidating all of
this code into the lsm_fill_user_ctx() helper.
The buffer padding is also modified from a fixed 8-byte alignment to
an alignment that matches the word length of the machine
(BITS_PER_LONG / 8).
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Add lsm_name_to_attr(), which translates a text string to a
LSM_ATTR value if one is available.
Add lsm_fill_user_ctx(), which fills a struct lsm_ctx, including
the trailing attribute value.
Both are used in module specific components of LSM system calls.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Create a system call lsm_get_self_attr() to provide the security
module maintained attributes of the current process.
Create a system call lsm_set_self_attr() to set a security
module maintained attribute of the current process.
Historically these attributes have been exposed to user space via
entries in procfs under /proc/self/attr.
The attribute value is provided in a lsm_ctx structure. The structure
identifies the size of the attribute, and the attribute value. The format
of the attribute value is defined by the security module. A flags field
is included for LSM specific information. It is currently unused and must
be 0. The total size of the data, including the lsm_ctx structure and any
padding, is maintained as well.
struct lsm_ctx {
__u64 id;
__u64 flags;
__u64 len;
__u64 ctx_len;
__u8 ctx[];
};
Two new LSM hooks are used to interface with the LSMs.
security_getselfattr() collects the lsm_ctx values from the
LSMs that support the hook, accounting for space requirements.
security_setselfattr() identifies which LSM the attribute is
intended for and passes it along.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Use the LSM ID number instead of the LSM name to identify which
security module's attibute data should be shown in /proc/self/attr.
The security_[gs]etprocattr() functions have been changed to expect
the LSM ID. The change from a string comparison to an integer comparison
in these functions will provide a minor performance improvement.
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Mickael Salaun <mic@digikod.net>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
As LSMs are registered add their lsm_id pointers to a table.
This will be used later for attribute reporting.
Determine the number of possible security modules based on
their respective CONFIG options. This allows the number to be
known at build time. This allows data structures and tables
to use the constant.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Mickael Salaun <mic@digikod.net>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
The "sb_kern_mount" hook has implementation registered in SELinux.
Looking at the function implementation we observe that the "sb"
parameter is not changing.
Mark the "sb" parameter of LSM hook security_sb_kern_mount() as "const"
since it will not be changing in the LSM hook.
Signed-off-by: Khadija Kamran <kamrankhadijadj@gmail.com>
[PM: minor merge fuzzing due to other constification patches]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Three LSMs register the implementations for the 'bprm_committed_creds()'
hook: AppArmor, SELinux and tomoyo. Looking at the function
implementations we may observe that the 'bprm' parameter is not changing.
Mark the 'bprm' parameter of LSM hook security_bprm_committed_creds() as
'const' since it will not be changing in the LSM hook.
Signed-off-by: Khadija Kamran <kamrankhadijadj@gmail.com>
[PM: minor merge fuzzing due to other constification patches]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
The 'bprm_committing_creds' hook has implementations registered in
SELinux and Apparmor. Looking at the function implementations we observe
that the 'bprm' parameter is not changing.
Mark the 'bprm' parameter of LSM hook security_bprm_committing_creds()
as 'const' since it will not be changing in the LSM hook.
Signed-off-by: Khadija Kamran <kamrankhadijadj@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
