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git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull sysctl updates from Luis Chamberlain:
"This only does a few sysctl moves from the kernel/sysctl.c file, the
rest of the work has been put towards deprecating two API calls which
incur recursion and prevent us from simplifying the registration
process / saving memory per move. Most of the changes have been
soaking on linux-next since v6.3-rc3.
I've slowed down the kernel/sysctl.c moves due to Matthew Wilcox's
feedback that we should see if we could *save* memory with these moves
instead of incurring more memory. We currently incur more memory since
when we move a syctl from kernel/sysclt.c out to its own file we end
up having to add a new empty sysctl used to register it. To achieve
saving memory we want to allow syctls to be passed without requiring
the end element being empty, and just have our registration process
rely on ARRAY_SIZE(). Without this, supporting both styles of sysctls
would make the sysctl registration pretty brittle, hard to read and
maintain as can be seen from Meng Tang's efforts to do just this [0].
Fortunately, in order to use ARRAY_SIZE() for all sysctl registrations
also implies doing the work to deprecate two API calls which use
recursion in order to support sysctl declarations with subdirectories.
And so during this development cycle quite a bit of effort went into
this deprecation effort. I've annotated the following two APIs are
deprecated and in few kernel releases we should be good to remove
them:
- register_sysctl_table()
- register_sysctl_paths()
During this merge window we should be able to deprecate and unexport
register_sysctl_paths(), we can probably do that towards the end of
this merge window.
Deprecating register_sysctl_table() will take a bit more time but this
pull request goes with a few example of how to do this.
As it turns out each of the conversions to move away from either of
these two API calls *also* saves memory. And so long term, all these
changes *will* prove to have saved a bit of memory on boot.
The way I see it then is if remove a user of one deprecated call, it
gives us enough savings to move one kernel/sysctl.c out from the
generic arrays as we end up with about the same amount of bytes.
Since deprecating register_sysctl_table() and register_sysctl_paths()
does not require maintainer coordination except the final unexport
you'll see quite a bit of these changes from other pull requests, I've
just kept the stragglers after rc3"
Link: https://lkml.kernel.org/r/ZAD+cpbrqlc5vmry@bombadil.infradead.org [0]
* tag 'sysctl-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (29 commits)
fs: fix sysctls.c built
mm: compaction: remove incorrect #ifdef checks
mm: compaction: move compaction sysctl to its own file
mm: memory-failure: Move memory failure sysctls to its own file
arm: simplify two-level sysctl registration for ctl_isa_vars
ia64: simplify one-level sysctl registration for kdump_ctl_table
utsname: simplify one-level sysctl registration for uts_kern_table
ntfs: simplfy one-level sysctl registration for ntfs_sysctls
coda: simplify one-level sysctl registration for coda_table
fs/cachefiles: simplify one-level sysctl registration for cachefiles_sysctls
xfs: simplify two-level sysctl registration for xfs_table
nfs: simplify two-level sysctl registration for nfs_cb_sysctls
nfs: simplify two-level sysctl registration for nfs4_cb_sysctls
lockd: simplify two-level sysctl registration for nlm_sysctls
proc_sysctl: enhance documentation
xen: simplify sysctl registration for balloon
md: simplify sysctl registration
hv: simplify sysctl registration
scsi: simplify sysctl registration with register_sysctl()
csky: simplify alignment sysctl registration
...
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Using register_sysctl_paths() is really only needed if you have
subdirectories with entries. We can use the simple register_sysctl()
instead.
Acked-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
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After working with the larger SELinux-based distros for several
years, we're finally at a place where we can disable the SELinux
runtime disable functionality. The existing kernel deprecation
notice explains the functionality and why we want to remove it:
The selinuxfs "disable" node allows SELinux to be disabled at
runtime prior to a policy being loaded into the kernel. If
disabled via this mechanism, SELinux will remain disabled until
the system is rebooted.
The preferred method of disabling SELinux is via the "selinux=0"
boot parameter, but the selinuxfs "disable" node was created to
make it easier for systems with primitive bootloaders that did not
allow for easy modification of the kernel command line.
Unfortunately, allowing for SELinux to be disabled at runtime makes
it difficult to secure the kernel's LSM hooks using the
"__ro_after_init" feature.
It is that last sentence, mentioning the '__ro_after_init' hardening,
which is the real motivation for this change, and if you look at the
diffstat you'll see that the impact of this patch reaches across all
the different LSMs, helping prevent tampering at the LSM hook level.
From a SELinux perspective, it is important to note that if you
continue to disable SELinux via "/etc/selinux/config" it may appear
that SELinux is disabled, but it is simply in an uninitialized state.
If you load a policy with `load_policy -i`, you will see SELinux
come alive just as if you had loaded the policy during early-boot.
It is also worth noting that the "/sys/fs/selinux/disable" file is
always writable now, regardless of the Kconfig settings, but writing
to the file has no effect on the system, other than to display an
error on the console if a non-zero/true value is written.
Finally, in the several years where we have been working on
deprecating this functionality, there has only been one instance of
someone mentioning any user visible breakage. In this particular
case it was an individual's kernel test system, and the workaround
documented in the deprecation notice ("selinux=0" on the kernel
command line) resolved the issue without problem.
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Convert to struct mnt_idmap.
Remove legacy file_mnt_user_ns() and mnt_user_ns().
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor
Pull apparmor updates from John Johansen:
"Features:
- switch to zstd compression for profile raw data
Cleanups:
- simplify obtaining the newest label on a cred
- remove useless static inline functions
- compute permission conversion on policy unpack
- refactor code to share common permissins
- refactor unpack to group policy backwards compatiblity code
- add __init annotation to aa_{setup/teardown}_dfa_engine()
Bug Fixes:
- fix a memleak in
- multi_transaction_new()
- free_ruleset()
- unpack_profile()
- alloc_ns()
- fix lockdep warning when removing a namespace
- fix regression in stacking due to label flags
- fix loading of child before parent
- fix kernel-doc comments that differ from fns
- fix spelling errors in comments
- store return value of unpack_perms_table() to signed variable"
* tag 'apparmor-pr-2022-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor: (64 commits)
apparmor: Fix uninitialized symbol 'array_size' in policy_unpack_test.c
apparmor: Add __init annotation to aa_{setup/teardown}_dfa_engine()
apparmor: Fix memleak in alloc_ns()
apparmor: Fix memleak issue in unpack_profile()
apparmor: fix a memleak in free_ruleset()
apparmor: Fix spelling of function name in comment block
apparmor: Use pointer to struct aa_label for lbs_cred
AppArmor: Fix kernel-doc
LSM: Fix kernel-doc
AppArmor: Fix kernel-doc
apparmor: Fix loading of child before parent
apparmor: refactor code that alloc null profiles
apparmor: fix obsoleted comments for aa_getprocattr() and audit_resource()
apparmor: remove useless static inline functions
apparmor: Fix unpack_profile() warn: passing zero to 'ERR_PTR'
apparmor: fix uninitialize table variable in error in unpack_trans_table
apparmor: store return value of unpack_perms_table() to signed variable
apparmor: Fix kunit test for out of bounds array
apparmor: Fix decompression of rawdata for read back to userspace
apparmor: Fix undefined references to zstd_ symbols
...
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull lsm updates from Paul Moore:
- Improve the error handling in the device cgroup such that memory
allocation failures when updating the access policy do not
potentially alter the policy.
- Some minor fixes to reiserfs to ensure that it properly releases
LSM-related xattr values.
- Update the security_socket_getpeersec_stream() LSM hook to take
sockptr_t values.
Previously the net/BPF folks updated the getsockopt code in the
network stack to leverage the sockptr_t type to make it easier to
pass both kernel and __user pointers, but unfortunately when they did
so they didn't convert the LSM hook.
While there was/is no immediate risk by not converting the LSM hook,
it seems like this is a mistake waiting to happen so this patch
proactively does the LSM hook conversion.
- Convert vfs_getxattr_alloc() to return an int instead of a ssize_t
and cleanup the callers. Internally the function was never going to
return anything larger than an int and the callers were doing some
very odd things casting the return value; this patch fixes all that
and helps bring a bit of sanity to vfs_getxattr_alloc() and its
callers.
- More verbose, and helpful, LSM debug output when the system is booted
with "lsm.debug" on the command line. There are examples in the
commit description, but the quick summary is that this patch provides
better information about which LSMs are enabled and the ordering in
which they are processed.
- General comment and kernel-doc fixes and cleanups.
* tag 'lsm-pr-20221212' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
lsm: Fix description of fs_context_parse_param
lsm: Add/fix return values in lsm_hooks.h and fix formatting
lsm: Clarify documentation of vm_enough_memory hook
reiserfs: Add missing calls to reiserfs_security_free()
lsm,fs: fix vfs_getxattr_alloc() return type and caller error paths
device_cgroup: Roll back to original exceptions after copy failure
LSM: Better reporting of actual LSMs at boot
lsm: make security_socket_getpeersec_stream() sockptr_t safe
audit: Fix some kernel-doc warnings
lsm: remove obsoleted comments for security hooks
fs: edit a comment made in bad taste
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git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux
Pull landlock updates from Mickaël Salaün:
"This adds file truncation support to Landlock, contributed by Günther
Noack. As described by Günther [1], the goal of these patches is to
work towards a more complete coverage of file system operations that
are restrictable with Landlock.
The known set of currently unsupported file system operations in
Landlock is described at [2]. Out of the operations listed there,
truncate is the only one that modifies file contents, so these patches
should make it possible to prevent the direct modification of file
contents with Landlock.
The new LANDLOCK_ACCESS_FS_TRUNCATE access right covers both the
truncate(2) and ftruncate(2) families of syscalls, as well as open(2)
with the O_TRUNC flag. This includes usages of creat() in the case
where existing regular files are overwritten.
Additionally, this introduces a new Landlock security blob associated
with opened files, to track the available Landlock access rights at
the time of opening the file. This is in line with Unix's general
approach of checking the read and write permissions during open(), and
associating this previously checked authorization with the opened
file. An ongoing patch documents this use case [3].
In order to treat truncate(2) and ftruncate(2) calls differently in an
LSM hook, we split apart the existing security_path_truncate hook into
security_path_truncate (for truncation by path) and
security_file_truncate (for truncation of previously opened files)"
Link: https://lore.kernel.org/r/20221018182216.301684-1-gnoack3000@gmail.com [1]
Link: https://www.kernel.org/doc/html/v6.1/userspace-api/landlock.html#filesystem-flags [2]
Link: https://lore.kernel.org/r/20221209193813.972012-1-mic@digikod.net [3]
* tag 'landlock-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
samples/landlock: Document best-effort approach for LANDLOCK_ACCESS_FS_REFER
landlock: Document Landlock's file truncation support
samples/landlock: Extend sample tool to support LANDLOCK_ACCESS_FS_TRUNCATE
selftests/landlock: Test ftruncate on FDs created by memfd_create(2)
selftests/landlock: Test FD passing from restricted to unrestricted processes
selftests/landlock: Locally define __maybe_unused
selftests/landlock: Test open() and ftruncate() in multiple scenarios
selftests/landlock: Test file truncation support
landlock: Support file truncation
landlock: Document init_layer_masks() helper
landlock: Refactor check_access_path_dual() into is_access_to_paths_allowed()
security: Create file_truncate hook from path_truncate hook
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Commit 4ff09db1b79b ("bpf: net: Change sk_getsockopt() to take the
sockptr_t argument") made it possible to call sk_getsockopt()
with both user and kernel address space buffers through the use of
the sockptr_t type. Unfortunately at the time of conversion the
security_socket_getpeersec_stream() LSM hook was written to only
accept userspace buffers, and in a desire to avoid having to change
the LSM hook the commit author simply passed the sockptr_t's
userspace buffer pointer. Since the only sk_getsockopt() callers
at the time of conversion which used kernel sockptr_t buffers did
not allow SO_PEERSEC, and hence the
security_socket_getpeersec_stream() hook, this was acceptable but
also very fragile as future changes presented the possibility of
silently passing kernel space pointers to the LSM hook.
There are several ways to protect against this, including careful
code review of future commits, but since relying on code review to
catch bugs is a recipe for disaster and the upstream eBPF maintainer
is "strongly against defensive programming", this patch updates the
LSM hook, and all of the implementations to support sockptr_t and
safely handle both user and kernel space buffers.
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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We already ported most parts and filesystems over for v6.0 to the new
vfs{g,u}id_t type and associated helpers for v6.0. Convert the remaining
places so we can remove all the old helpers.
This is a non-functional change.
Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
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According to the implementations of cred_label() and set_cred_label(),
we should use pointer to struct aa_label for lbs_cred instead of struct
aa_task_ctx, this patch fixes it.
Fixes: bbd3662a8348 ("Infrastructure management of the cred security blob")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
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security/apparmor/lsm.c:753: warning: expecting prototype for apparmor_bprm_committed_cred(). Prototype was for apparmor_bprm_committed_creds() instead.
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2338
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
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Like path_truncate, the file_truncate hook also restricts file
truncation, but is called in the cases where truncation is attempted
on an already-opened file.
This is required in a subsequent commit to handle ftruncate()
operations differently to truncate() operations.
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20221018182216.301684-2-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
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Unfortunately the switch to using zstd compression did not properly
ifdef all the code that uses zstd_ symbols. So that if exporting of
binary policy is disabled in the config the compile will fail with the
following errors
security/apparmor/lsm.c:1545: undefined reference to `zstd_min_clevel'
aarch64-linux-ld: security/apparmor/lsm.c:1545: undefined reference to `zstd_max_clevel'
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 52ccc20c652b ("apparmor: use zstd compression for profile data")
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Jon Tourville <jon.tourville@canonical.com>
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Convert profile->rules to a list as the next step towards supporting
multiple rulesets in a profile. For this step only support a single
list entry item. The logic for iterating the list will come as a
separate step.
Signed-off-by: John Johansen <john.johansen@canonical.com>
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In preparation for moving from a single set of rules and a single
attachment to multiple rulesets and attachments separate from the
profile refactor attachment information and ruleset info into their
own structures.
Signed-off-by: John Johansen <john.johansen@canonical.com>
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Audit messages currently don't contain the mediation class which can
make them less clear than they should be in some circumstances. With
newer mediation classes coming this potential confusion will become
worse.
Fix this by adding the mediatin class to the messages.
Signed-off-by: John Johansen <john.johansen@canonical.com>
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Change the algorithm used by apparmor to compress profile data from
zlib to zstd, using the new zstd API introduced in 5.16.
Zstd provides a larger range of compression levels than zlib and
significantly better performance at the default level (for a relatively
small increase in compressed size).
The apparmor module parameter raw_data_compression_level is now clamped
to the minimum and maximum compression levels reported by the zstd
library. A compression level of 0 retains the previous behavior of
disabling policy compression instead of using zstd's behavior, which is
to use the default compression level.
Signed-off-by: Jon Tourville <jon.tourville@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
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cast of ->d_name.name to char * is completely wrong - nothing is
allowed to modify its contents.
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Commit 5bfcbd22ee4e ("apparmor: Enable tuning of policy paranoid load for
embedded systems") introduces the config SECURITY_APPARMOR_PARANOID_LOAD,
but then refers in the code to SECURITY_PARANOID_LOAD; note the missing
APPARMOR in the middle.
Correct this to the introduced and intended config option.
Fixes: 5bfcbd22ee4e ("apparmor: Enable tuning of policy paranoid load for embedded systems")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
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Displaying the mode as part of the seectx takes up unnecessary memory,
makes it so we can't use refcounted secctx so we need to alloc/free on
every conversion from secid to secctx and introduces a space that
could be potentially mishandled by tooling.
Eg. In an audit record we get
subj_type=firefix (enforce)
Having the mode reported is not necessary, and might even be confusing
eg. when writing an audit rule to match the above record field you
would use
-F subj_type=firefox
ie. the mode is not included. AppArmor provides ways to find the mode
without reporting as part of the secctx. So disable this by default
before its use is wide spread and we can't. For now we add a sysctl
to control the behavior as we can't guarantee no one is using this.
Acked-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
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XArrays are a better match than IDR for how AppArmor is mapping
secids. Specifically AppArmor is trying to keep the allocation
dense. XArrays also have the advantage of avoiding the complexity IDRs
preallocation.
In addition this avoids/fixes a lockdep issue raised in the LKML thread
"Linux 5.18-rc4"
where there is a report of an interaction between apparmor and IPC,
this warning may have been spurious as the reported issue is in a
per-cpu local lock taken by the IDR. With the one side in the IPC id
allocation and the other in AppArmor's secid allocation.
Description by John Johansen <john.johansen@canonical.com>
Message-Id: <226cee6a-6ca1-b603-db08-8500cd8f77b7@gnuweeb.org>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
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Separate kernel objects from unconfined. This is done so we can
distinguish between the two in debugging, auditing and in preparation
for being able to replace unconfined, which is not appropriate for the
kernel.
The kernel label will continue to behave similar to unconfined.
Acked-by: Jon Tourville <jon.tourville@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
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Return value from nf_register_net_hooks() directly instead
of taking this in another redundant variable.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: CGEL ZTE <cgel.zte@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
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AppArmor by default does an extensive check on loaded policy that
can take quite some time on limited resource systems. Allow
disabling this check for embedded systems where system images are
readonly and have checksumming making the need for the embedded
policy to be fully checked to be redundant.
Note: basic policy checks are still done.
Signed-off-by: John Johansen <john.johansen@canonical.com>
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Embedded systems have limited space and don't need the introspection
or checkpoint restore capability provided by exporting the raw
profile binary data so make it so make it a config option.
This will reduce run time memory use and also speed up policy loads.
Signed-off-by: John Johansen <john.johansen@canonical.com>
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Fix function name in lsm.c kernel-doc comment
to remove some warnings found by running scripts/kernel-doc,
which is caused by using 'make W=1'.
security/apparmor/lsm.c:819: warning: expecting prototype for
apparmor_clone_security(). Prototype was for
apparmor_sk_clone_security() instead
security/apparmor/lsm.c:923: warning: expecting prototype for
apparmor_socket_list(). Prototype was for apparmor_socket_listen()
instead
security/apparmor/lsm.c:1028: warning: expecting prototype for
apparmor_getsockopt(). Prototype was for apparmor_socket_getsockopt()
instead
security/apparmor/lsm.c:1038: warning: expecting prototype for
apparmor_setsockopt(). Prototype was for apparmor_socket_setsockopt()
instead
ecurity/apparmor/lsm.c:1061: warning: expecting prototype for
apparmor_socket_sock_recv_skb(). Prototype was for
apparmor_socket_sock_rcv_skb() instead
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
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In order to be able to identify a file exchange with renameat2(2) and
RENAME_EXCHANGE, which will be useful for Landlock [1], propagate the
rename flags to LSMs. This may also improve performance because of the
switch from two set of LSM hook calls to only one, and because LSMs
using this hook may optimize the double check (e.g. only one lock,
reduce the number of path walks).
AppArmor, Landlock and Tomoyo are updated to leverage this change. This
should not change the current behavior (same check order), except
(different level of) speed boosts.
[1] https://lore.kernel.org/r/20220221212522.320243-1-mic@digikod.net
Cc: James Morris <jmorris@namei.org>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Serge E. Hallyn <serge@hallyn.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Link: https://lore.kernel.org/r/20220506161102.525323-7-mic@digikod.net
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The security_task_getsecid_subj() LSM hook invites misuse by allowing
callers to specify a task even though the hook is only safe when the
current task is referenced. Fix this by removing the task_struct
argument to the hook, requiring LSM implementations to use the
current task. While we are changing the hook declaration we also
rename the function to security_current_getsecid_subj() in an effort
to reinforce that the hook captures the subjective credentials of the
current task and not an arbitrary task on the system.
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor
Pull apparmor updates from John Johansen:
"Features
- use per file locks for transactional queries
- update policy management capability checks to work with LSM stacking
Bug Fixes:
- check/put label on apparmor_sk_clone_security()
- fix error check on update of label hname
- fix introspection of of task mode for unconfined tasks
Cleanups:
- avoid -Wempty-body warning
- remove duplicated 'Returns:' comments
- fix doc warning
- remove unneeded one-line hook wrappers
- use struct_size() helper in kzalloc()
- fix zero-length compiler warning in AA_BUG()
- file.h: delete duplicated word
- delete repeated words in comments
- remove repeated declaration"
* tag 'apparmor-pr-2021-11-10' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
apparmor: remove duplicated 'Returns:' comments
apparmor: remove unneeded one-line hook wrappers
apparmor: Use struct_size() helper in kzalloc()
apparmor: fix zero-length compiler warning in AA_BUG()
apparmor: use per file locks for transactional queries
apparmor: fix doc warning
apparmor: Remove the repeated declaration
apparmor: avoid -Wempty-body warning
apparmor: Fix internal policy capable check for policy management
apparmor: fix error check
security: apparmor: delete repeated words in comments
security: apparmor: file.h: delete duplicated word
apparmor: switch to apparmor to internal capable check for policy management
apparmor: update policy capable checks to use a label
apparmor: fix introspection of of task mode for unconfined tasks
apparmor: check/put label on apparmor_sk_clone_security()
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Use the common function directly.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>
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Of the three LSMs that implement the security_task_getsecid() LSM
hook, all three LSMs provide the task's objective security
credentials. This turns out to be unfortunate as most of the hook's
callers seem to expect the task's subjective credentials, although
a small handful of callers do correctly expect the objective
credentials.
This patch is the first step towards fixing the problem: it splits
the existing security_task_getsecid() hook into two variants, one
for the subjective creds, one for the objective creds.
void security_task_getsecid_subj(struct task_struct *p,
u32 *secid);
void security_task_getsecid_obj(struct task_struct *p,
u32 *secid);
While this patch does fix all of the callers to use the correct
variant, in order to keep this patch focused on the callers and to
ease review, the LSMs continue to use the same implementation for
both hooks. The net effect is that this patch should not change
the behavior of the kernel in any way, it will be up to the latter
LSM specific patches in this series to change the hook
implementations and return the correct credentials.
Acked-by: Mimi Zohar <zohar@linux.ibm.com> (IMA)
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Previously the policy capable checks assumed they were using the
current task. Make them take the task label so the query can be
made against an arbitrary task.
Signed-off-by: John Johansen <john.johansen@canonical.com>
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The i_uid and i_gid are mostly used when logging for AppArmor. This is
broken in a bunch of places where the global root id is reported instead
of the i_uid or i_gid of the file. Nonetheless, be kind and log the
mapped inode if we're coming from an idmapped mount. If the initial user
namespace is passed nothing changes so non-idmapped mounts will see
identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-26-christian.brauner@ubuntu.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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A followup change to tcp_request_sock_op would have to drop the 'const'
qualifier from the 'route_req' function as the
'security_inet_conn_request' call is moved there - and that function
expects a 'struct sock *'.
However, it turns out its also possible to add a const qualifier to
security_inet_conn_request instead.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor
Pull apparmor updates from John Johansen:
"Features:
- Replace zero-length array with flexible-array
- add a valid state flags check
- add consistency check between state and dfa diff encode flags
- add apparmor subdir to proc attr interface
- fail unpack if profile mode is unknown
- add outofband transition and use it in xattr match
- ensure that dfa state tables have entries
Cleanups:
- Use true and false for bool variable
- Remove semicolon
- Clean code by removing redundant instructions
- Replace two seq_printf() calls by seq_puts() in aa_label_seq_xprint()
- remove duplicate check of xattrs on profile attachment
- remove useless aafs_create_symlink
Bug fixes:
- Fix memory leak of profile proxy
- fix introspection of of task mode for unconfined tasks
- fix nnp subset test for unconfined
- check/put label on apparmor_sk_clone_security()"
* tag 'apparmor-pr-2020-06-07' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
apparmor: Fix memory leak of profile proxy
apparmor: fix introspection of of task mode for unconfined tasks
apparmor: check/put label on apparmor_sk_clone_security()
apparmor: Use true and false for bool variable
security/apparmor/label.c: Clean code by removing redundant instructions
apparmor: Replace zero-length array with flexible-array
apparmor: ensure that dfa state tables have entries
apparmor: remove duplicate check of xattrs on profile attachment.
apparmor: add outofband transition and use it in xattr match
apparmor: fail unpack if profile mode is unknown
apparmor: fix nnp subset test for unconfined
apparmor: remove useless aafs_create_symlink
apparmor: add proc subdir to attrs
apparmor: add consistency check between state and dfa diff encode flags
apparmor: add a valid state flags check
AppArmor: Remove semicolon
apparmor: Replace two seq_printf() calls by seq_puts() in aa_label_seq_xprint()
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Currently apparmor_sk_clone_security() does not check for existing
label/peer in the 'new' struct sock; it just overwrites it, if any
(with another reference to the label of the source sock.)
static void apparmor_sk_clone_security(const struct sock *sk,
struct sock *newsk)
{
struct aa_sk_ctx *ctx = SK_CTX(sk);
struct aa_sk_ctx *new = SK_CTX(newsk);
new->label = aa_get_label(ctx->label);
new->peer = aa_get_label(ctx->peer);
}
This might leak label references, which might overflow under load.
Thus, check for and put labels, to prevent such errors.
Note this is similarly done on:
static int apparmor_socket_post_create(struct socket *sock, ...)
...
if (sock->sk) {
struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
aa_put_label(ctx->label);
ctx->label = aa_get_label(label);
}
...
Context:
-------
The label reference count leak is observed if apparmor_sock_graft()
is called previously: this sets the 'ctx->label' field by getting
a reference to the current label (later overwritten, without put.)
static void apparmor_sock_graft(struct sock *sk, ...)
{
struct aa_sk_ctx *ctx = SK_CTX(sk);
if (!ctx->label)
ctx->label = aa_get_current_label();
}
And that is the case on crypto/af_alg.c:af_alg_accept():
int af_alg_accept(struct sock *sk, struct socket *newsock, ...)
...
struct sock *sk2;
...
sk2 = sk_alloc(...);
...
security_sock_graft(sk2, newsock);
security_sk_clone(sk, sk2);
...
Apparently both calls are done on their own right, especially for
other LSMs, being introduced in 2010/2014, before apparmor socket
mediation in 2017 (see commits [1,2,3,4]).
So, it looks OK there! Let's fix the reference leak in apparmor.
Test-case:
---------
Exercise that code path enough to overflow label reference count.
$ cat aa-refcnt-af_alg.c
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <linux/if_alg.h>
int main() {
int sockfd;
struct sockaddr_alg sa;
/* Setup the crypto API socket */
sockfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
if (sockfd < 0) {
perror("socket");
return 1;
}
memset(&sa, 0, sizeof(sa));
sa.salg_family = AF_ALG;
strcpy((char *) sa.salg_type, "rng");
strcpy((char *) sa.salg_name, "stdrng");
if (bind(sockfd, (struct sockaddr *) &sa, sizeof(sa)) < 0) {
perror("bind");
return 1;
}
/* Accept a "connection" and close it; repeat. */
while (!close(accept(sockfd, NULL, 0)));
return 0;
}
$ gcc -o aa-refcnt-af_alg aa-refcnt-af_alg.c
$ ./aa-refcnt-af_alg
<a few hours later>
[ 9928.475953] refcount_t overflow at apparmor_sk_clone_security+0x37/0x70 in aa-refcnt-af_alg[1322], uid/euid: 1000/1000
...
[ 9928.507443] RIP: 0010:apparmor_sk_clone_security+0x37/0x70
...
[ 9928.514286] security_sk_clone+0x33/0x50
[ 9928.514807] af_alg_accept+0x81/0x1c0 [af_alg]
[ 9928.516091] alg_accept+0x15/0x20 [af_alg]
[ 9928.516682] SYSC_accept4+0xff/0x210
[ 9928.519609] SyS_accept+0x10/0x20
[ 9928.520190] do_syscall_64+0x73/0x130
[ 9928.520808] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Note that other messages may be seen, not just overflow, depending on
the value being incremented by kref_get(); on another run:
[ 7273.182666] refcount_t: saturated; leaking memory.
...
[ 7273.185789] refcount_t: underflow; use-after-free.
Kprobes:
-------
Using kprobe events to monitor sk -> sk_security -> label -> count (kref):
Original v5.7 (one reference leak every iteration)
... (af_alg_accept+0x0/0x1c0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd2
... (af_alg_release_parent+0x0/0xd0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd4
... (af_alg_accept+0x0/0x1c0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd3
... (af_alg_release_parent+0x0/0xd0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd5
... (af_alg_accept+0x0/0x1c0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd4
... (af_alg_release_parent+0x0/0xd0) label=0xffff8a0f36c25eb0 label_refcnt=0x11fd6
Patched v5.7 (zero reference leak per iteration)
... (af_alg_accept+0x0/0x1c0) label=0xffff9ff376c25eb0 label_refcnt=0x593
... (af_alg_release_parent+0x0/0xd0) label=0xffff9ff376c25eb0 label_refcnt=0x594
... (af_alg_accept+0x0/0x1c0) label=0xffff9ff376c25eb0 label_refcnt=0x593
... (af_alg_release_parent+0x0/0xd0) label=0xffff9ff376c25eb0 label_refcnt=0x594
... (af_alg_accept+0x0/0x1c0) label=0xffff9ff376c25eb0 label_refcnt=0x593
... (af_alg_release_parent+0x0/0xd0) label=0xffff9ff376c25eb0 label_refcnt=0x594
Commits:
-------
[1] commit 507cad355fc9 ("crypto: af_alg - Make sure sk_security is initialized on accept()ed sockets")
[2] commit 4c63f83c2c2e ("crypto: af_alg - properly label AF_ALG socket")
[3] commit 2acce6aa9f65 ("Networking") a.k.a ("crypto: af_alg - Avoid sock_graft call warning)
[4] commit 56974a6fcfef ("apparmor: add base infastructure for socket mediation")
Fixes: 56974a6fcfef ("apparmor: add base infastructure for socket mediation")
Reported-by: Brian Moyles <bmoyles@netflix.com>
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
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Currently apparmor_sk_clone_security() does not check for existing
label/peer in the 'new' struct sock; it just overwrites it, if any
(with another reference to the label of the source sock.)
static void apparmor_sk_clone_security(const struct sock *sk,
struct sock *newsk)
{
struct aa_sk_ctx *ctx = SK_CTX(sk);
struct aa_sk_ctx *new = SK_CTX(newsk);
new->label = aa_get_label(ctx->label);
new->peer = aa_get_label(ctx->peer);
}
This might leak label references, which might overflow under load.
Thus, check for and put labels, to prevent such errors.
Note this is similarly done on:
static int apparmor_socket_post_create(struct socket *sock, ...)
...
if (sock->sk) {
struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
aa_put_label(ctx->label);
ctx->label = aa_get_label(label);
}
...
Context:
-------
The label reference count leak is observed if apparmor_sock_graft()
is called previously: this sets the 'ctx->label' field by getting
a reference to the current label (later overwritten, without put.)
static void apparmor_sock_graft(struct sock *sk, ...)
{
struct aa_sk_ctx *ctx = SK_CTX(sk);
if (!ctx->label)
ctx->label = aa_get_current_label();
}
And that is the case on crypto/af_alg.c:af_alg_accept():
int af_alg_accept(struct sock *sk, struct socket *newsock, ...)
...
struct sock *sk2;
...
sk2 = sk_alloc(...);
...
security_sock_graft(sk2, newsock);
security_sk_clone(sk, sk2);
...
Apparently both calls are done on their own right, especially for
other LSMs, being introduced in 2010/2014, before apparmor socket
mediation in 2017 (see commits [1,2,3,4]).
So, it looks OK there! Let's fix the reference leak in apparmor.
Test-case:
---------
Exercise that code path enough to overflow label reference count.
$ cat aa-refcnt-af_alg.c
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <linux/if_alg.h>
int main() {
int sockfd;
struct sockaddr_alg sa;
/* Setup the crypto API socket */
sockfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
if (sockfd < 0) {
perror("socket");
return 1;
}
memset(&sa, 0, sizeof(sa));
sa.salg_family = AF_ALG;
strcpy((char *) sa.salg_type, "rng");
strcpy((char *) sa.salg_name, "stdrng");
if (bind(sockfd, (struct sockaddr *) &sa, sizeof(sa)) < 0) {
perror("bind");
return 1;
}
/* Accept a "connection" and close it; repeat. */
while (!close(accept(sockfd, NULL, 0)));
return 0;
}
$ gcc -o aa-refcnt-af_alg aa-refcnt-af_alg.c
$ ./aa-refcnt-af_alg
<a few hours later>
[ 9928.475953] refcount_t overflow at apparmor_sk_clone_security+0x37/0x70 in aa-refcnt-af_alg[1322], uid/euid: 1000/1000
...
[ 9928.507443] RIP: 0010:apparmor_sk_clone_security+0x37/0x70
...
[ 9928.514286] security_sk_clone+0x33/0x50
[ 9928.514807] af_alg_accept+0x81/0x1c0 [af_alg]
[ 9928.516091] alg_accept+0x15/0x20 [af_alg]
[ 9928.516682] SYSC_accept4+0xff/0x210
[ 9928.519609] SyS_accept+0x10/0x20
[ 9928.520190] do_syscall_64+0x73/0x130
[ 9928.520808] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Note that other messages may be seen, not just overflow, depending on
the value being incremented by kref_get(); on another run:
[ 7273.182666] refcount_t: saturated; leaking memory.
...
[ 7273.185789] refcount_t: underflow; use-after-free.
Kprobes:
-------
Using kprobe events to monitor sk -> sk_security -> label -> count (kref):
Original v5.7 (one reference leak every iteration)
... (af_alg_accept+0x0/0x1c0) |
