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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, ...)
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull LSM fixes from Paul Moore:
- Add a missing security_mmap_file() check to the remap_file_pages()
syscall
- Properly reference the SELinux and Smack LSM blobs in the
security_watch_key() LSM hook
- Fix a random IPE selftest crash caused by a missing list terminator
in the test
* tag 'lsm-pr-20240923' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
ipe: Add missing terminator to list of unit tests
selinux,smack: properly reference the LSM blob in security_watch_key()
mm: call the security_mmap_file() LSM hook in remap_file_pages()
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Unfortunately when we migrated the lifecycle management of the key LSM
blob to the LSM framework we forgot to convert the security_watch_key()
callbacks for SELinux and Smack. This patch corrects this by making use
of the selinux_key() and smack_key() helper functions respectively.
This patch also removes some input checking in the Smack callback as it
is no longer needed.
Fixes: 5f8d28f6d7d5 ("lsm: infrastructure management of the key security blob")
Reported-by: syzbot+044fdf24e96093584232@syzkaller.appspotmail.com
Tested-by: syzbot+044fdf24e96093584232@syzkaller.appspotmail.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/pcmoore/lsm
Pull lsm updates from Paul Moore:
- Move the LSM framework to static calls
This transitions the vast majority of the LSM callbacks into static
calls. Those callbacks which haven't been converted were left as-is
due to the general ugliness of the changes required to support the
static call conversion; we can revisit those callbacks at a future
date.
- Add the Integrity Policy Enforcement (IPE) LSM
This adds a new LSM, Integrity Policy Enforcement (IPE). There is
plenty of documentation about IPE in this patches, so I'll refrain
from going into too much detail here, but the basic motivation behind
IPE is to provide a mechanism such that administrators can restrict
execution to only those binaries which come from integrity protected
storage, e.g. a dm-verity protected filesystem. You will notice that
IPE requires additional LSM hooks in the initramfs, dm-verity, and
fs-verity code, with the associated patches carrying ACK/review tags
from the associated maintainers. We couldn't find an obvious
maintainer for the initramfs code, but the IPE patchset has been
widely posted over several years.
Both Deven Bowers and Fan Wu have contributed to IPE's development
over the past several years, with Fan Wu agreeing to serve as the IPE
maintainer moving forward. Once IPE is accepted into your tree, I'll
start working with Fan to ensure he has the necessary accounts, keys,
etc. so that he can start submitting IPE pull requests to you
directly during the next merge window.
- Move the lifecycle management of the LSM blobs to the LSM framework
Management of the LSM blobs (the LSM state buffers attached to
various kernel structs, typically via a void pointer named "security"
or similar) has been mixed, some blobs were allocated/managed by
individual LSMs, others were managed by the LSM framework itself.
Starting with this pull we move management of all the LSM blobs,
minus the XFRM blob, into the framework itself, improving consistency
across LSMs, and reducing the amount of duplicated code across LSMs.
Due to some additional work required to migrate the XFRM blob, it has
been left as a todo item for a later date; from a practical
standpoint this omission should have little impact as only SELinux
provides a XFRM LSM implementation.
- Fix problems with the LSM's handling of F_SETOWN
The LSM hook for the fcntl(F_SETOWN) operation had a couple of
problems: it was racy with itself, and it was disconnected from the
associated DAC related logic in such a way that the LSM state could
be updated in cases where the DAC state would not. We fix both of
these problems by moving the security_file_set_fowner() hook into the
same section of code where the DAC attributes are updated. Not only
does this resolve the DAC/LSM synchronization issue, but as that code
block is protected by a lock, it also resolve the race condition.
- Fix potential problems with the security_inode_free() LSM hook
Due to use of RCU to protect inodes and the placement of the LSM hook
associated with freeing the inode, there is a bit of a challenge when
it comes to managing any LSM state associated with an inode. The VFS
folks are not open to relocating the LSM hook so we have to get
creative when it comes to releasing an inode's LSM state.
Traditionally we have used a single LSM callback within the hook that
is triggered when the inode is "marked for death", but not actually
released due to RCU.
Unfortunately, this causes problems for LSMs which want to take an
action when the inode's associated LSM state is actually released; so
we add an additional LSM callback, inode_free_security_rcu(), that is
called when the inode's LSM state is released in the RCU free
callback.
- Refactor two LSM hooks to better fit the LSM return value patterns
The vast majority of the LSM hooks follow the "return 0 on success,
negative values on failure" pattern, however, there are a small
handful that have unique return value behaviors which has caused
confusion in the past and makes it difficult for the BPF verifier to
properly vet BPF LSM programs. This includes patches to
convert two of these"special" LSM hooks to the common 0/-ERRNO pattern.
- Various cleanups and improvements
A handful of patches to remove redundant code, better leverage the
IS_ERR_OR_NULL() helper, add missing "static" markings, and do some
minor style fixups.
* tag 'lsm-pr-20240911' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (40 commits)
security: Update file_set_fowner documentation
fs: Fix file_set_fowner LSM hook inconsistencies
lsm: Use IS_ERR_OR_NULL() helper function
lsm: remove LSM_COUNT and LSM_CONFIG_COUNT
ipe: Remove duplicated include in ipe.c
lsm: replace indirect LSM hook calls with static calls
lsm: count the LSMs enabled at compile time
kernel: Add helper macros for loop unrolling
init/main.c: Initialize early LSMs after arch code, static keys and calls.
MAINTAINERS: add IPE entry with Fan Wu as maintainer
documentation: add IPE documentation
ipe: kunit test for parser
scripts: add boot policy generation program
ipe: enable support for fs-verity as a trust provider
fsverity: expose verified fsverity built-in signatures to LSMs
lsm: add security_inode_setintegrity() hook
ipe: add support for dm-verity as a trust provider
dm-verity: expose root hash digest and signature data to LSMs
block,lsm: add LSM blob and new LSM hooks for block devices
ipe: add permissive toggle
...
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux updates from Paul Moore:
- Ensure that both IPv4 and IPv6 connections are properly initialized
While we always properly initialized IPv4 connections early in their
life, we missed the necessary IPv6 change when we were adding IPv6
support.
- Annotate the SELinux inode revalidation function to quiet KCSAN
KCSAN correctly identifies a race in __inode_security_revalidate()
when we check to see if an inode's SELinux has been properly
initialized. While KCSAN is correct, it is an intentional choice made
for performance reasons; if necessary, we check the state a second
time, this time with a lock held, before initializing the inode's
state.
- Code cleanups, simplification, etc.
A handful of individual patches to simplify some SELinux kernel
logic, improve return code granularity via ERR_PTR(), follow the
guidance on using KMEM_CACHE(), and correct some minor style
problems.
* tag 'selinux-pr-20240911' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: fix style problems in security/selinux/include/audit.h
selinux: simplify avc_xperms_audit_required()
selinux: mark both IPv4 and IPv6 accepted connection sockets as labeled
selinux: replace kmem_cache_create() with KMEM_CACHE()
selinux: annotate false positive data race to avoid KCSAN warnings
selinux: refactor code to return ERR_PTR in selinux_netlbl_sock_genattr
selinux: Streamline type determination in security_compute_sid
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs file updates from Christian Brauner:
"This is the work to cleanup and shrink struct file significantly.
Right now, (focusing on x86) struct file is 232 bytes. After this
series struct file will be 184 bytes aka 3 cacheline and a spare 8
bytes for future extensions at the end of the struct.
With struct file being as ubiquitous as it is this should make a
difference for file heavy workloads and allow further optimizations in
the future.
- struct fown_struct was embedded into struct file letting it take up
32 bytes in total when really it shouldn't even be embedded in
struct file in the first place. Instead, actual users of struct
fown_struct now allocate the struct on demand. This frees up 24
bytes.
- Move struct file_ra_state into the union containg the cleanup hooks
and move f_iocb_flags out of the union. This closes a 4 byte hole
we created earlier and brings struct file to 192 bytes. Which means
struct file is 3 cachelines and we managed to shrink it by 40
bytes.
- Reorder struct file so that nothing crosses a cacheline.
I suspect that in the future we will end up reordering some members
to mitigate false sharing issues or just because someone does
actually provide really good perf data.
- Shrinking struct file to 192 bytes is only part of the work.
Files use a slab that is SLAB_TYPESAFE_BY_RCU and when a kmem cache
is created with SLAB_TYPESAFE_BY_RCU the free pointer must be
located outside of the object because the cache doesn't know what
part of the memory can safely be overwritten as it may be needed to
prevent object recycling.
That has the consequence that SLAB_TYPESAFE_BY_RCU may end up
adding a new cacheline.
So this also contains work to add a new kmem_cache_create_rcu()
function that allows the caller to specify an offset where the
freelist pointer is supposed to be placed. Thus avoiding the
implicit addition of a fourth cacheline.
- And finally this removes the f_version member in struct file.
The f_version member isn't particularly well-defined. It is mainly
used as a cookie to detect concurrent seeks when iterating
directories. But it is also abused by some subsystems for
completely unrelated things.
It is mostly a directory and filesystem specific thing that doesn't
really need to live in struct file and with its wonky semantics it
really lacks a specific function.
For pipes, f_version is (ab)used to defer poll notifications until
a write has happened. And struct pipe_inode_info is used by
multiple struct files in their ->private_data so there's no chance
of pushing that down into file->private_data without introducing
another pointer indirection.
But pipes don't rely on f_pos_lock so this adds a union into struct
file encompassing f_pos_lock and a pipe specific f_pipe member that
pipes can use. This union of course can be extended to other file
types and is similar to what we do in struct inode already"
* tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits)
fs: remove f_version
pipe: use f_pipe
fs: add f_pipe
ubifs: store cookie in private data
ufs: store cookie in private data
udf: store cookie in private data
proc: store cookie in private data
ocfs2: store cookie in private data
input: remove f_version abuse
ext4: store cookie in private data
ext2: store cookie in private data
affs: store cookie in private data
fs: add generic_llseek_cookie()
fs: use must_set_pos()
fs: add must_set_pos()
fs: add vfs_setpos_cookie()
s390: remove unused f_version
ceph: remove unused f_version
adi: remove unused f_version
mm: Removed @freeptr_offset to prevent doc warning
...
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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>
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull lsm fix from Paul Moore:
"One small patch to correct a NFS permissions problem with SELinux and
Smack"
* tag 'lsm-pr-20240830' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
selinux,smack: don't bypass permissions check in inode_setsecctx hook
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Marek Gresko reports that the root user on an NFS client is able to
change the security labels on files on an NFS filesystem that is
exported with root squashing enabled.
The end of the kerneldoc comment for __vfs_setxattr_noperm() states:
* This function requires the caller to lock the inode's i_mutex before it
* is executed. It also assumes that the caller will make the appropriate
* permission checks.
nfsd_setattr() does do permissions checking via fh_verify() and
nfsd_permission(), but those don't do all the same permissions checks
that are done by security_inode_setxattr() and its related LSM hooks do.
Since nfsd_setattr() is the only consumer of security_inode_setsecctx(),
simplest solution appears to be to replace the call to
__vfs_setxattr_noperm() with a call to __vfs_setxattr_locked(). This
fixes the above issue and has the added benefit of causing nfsd to
recall conflicting delegations on a file when a client tries to change
its security label.
Cc: stable@kernel.org
Reported-by: Marek Gresko <marek.gresko@protonmail.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218809
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Tested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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We do embedd struct fown_struct into struct file letting it take up 32
bytes in total. We could tweak struct fown_struct to be more compact but
really it shouldn't even be embedded in struct file in the first place.
Instead, actual users of struct fown_struct should allocate the struct
on demand. This frees up 24 bytes in struct file.
That will have some potentially user-visible changes for the ownership
fcntl()s. Some of them can now fail due to allocation failures.
Practically, that probably will almost never happen as the allocations
are small and they only happen once per file.
The fown_struct is used during kill_fasync() which is used by e.g.,
pipes to generate a SIGIO signal. Sending of such signals is conditional
on userspace having set an owner for the file using one of the F_OWNER
fcntl()s. Such users will be unaffected if struct fown_struct is
allocated during the fcntl() call.
There are a few subsystems that call __f_setown() expecting
file->f_owner to be allocated:
(1) tun devices
file->f_op->fasync::tun_chr_fasync()
-> __f_setown()
There are no callers of tun_chr_fasync().
(2) tty devices
file->f_op->fasync::tty_fasync()
-> __tty_fasync()
-> __f_setown()
tty_fasync() has no additional callers but __tty_fasync() has. Note
that __tty_fasync() only calls __f_setown() if the @on argument is
true. It's called from:
file->f_op->release::tty_release()
-> tty_release()
-> __tty_fasync()
-> __f_setown()
tty_release() calls __tty_fasync() with @on false
=> __f_setown() is never called from tty_release().
=> All callers of tty_release() are safe as well.
file->f_op->release::tty_open()
-> tty_release()
-> __tty_fasync()
-> __f_setown()
__tty_hangup() calls __tty_fasync() with @on false
=> __f_setown() is never called from tty_release().
=> All callers of __tty_hangup() are safe as well.
From the callchains it's obvious that (1) and (2) end up getting called
via file->f_op->fasync(). That can happen either through the F_SETFL
fcntl() with the FASYNC flag raised or via the FIOASYNC ioctl(). If
FASYNC is requested and the file isn't already FASYNC then
file->f_op->fasync() is called with @on true which ends up causing both
(1) and (2) to call __f_setown().
(1) and (2) are the only subsystems that call __f_setown() from the
file->f_op->fasync() handler. So both (1) and (2) have been updated to
allocate a struct fown_struct prior to calling fasync_helper() to
register with the fasync infrastructure. That's safe as they both call
fasync_helper() which also does allocations if @on is true.
The other interesting case are file leases:
(3) file leases
lease_manager_ops->lm_setup::lease_setup()
-> __f_setown()
Which in turn is called from:
generic_add_lease()
-> lease_manager_ops->lm_setup::lease_setup()
-> __f_setown()
So here again we can simply make generic_add_lease() allocate struct
fown_struct prior to the lease_manager_ops->lm_setup::lease_setup()
which happens under a spinlock.
With that the two remaining subsystems that call __f_setown() are:
(4) dnotify
(5) sockets
Both have their own custom ioctls to set struct fown_struct and both
have been converted to allocate a struct fown_struct on demand from
their respective ioctls.
Interactions with O_PATH are fine as well e.g., when opening a /dev/tty
as O_PATH then no file->f_op->open() happens thus no file->f_owner is
allocated. That's fine as no file operation will be set for those and
the device has never been opened. fcntl()s called on such things will
just allocate a ->f_owner on demand. Although I have zero idea why'd you
care about f_owner on an O_PATH fd.
Link: https://lore.kernel.org/r/20240813-work-f_owner-v2-1-4e9343a79f9f@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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KCSAN flags the check of isec->initialized by
__inode_security_revalidate() as a data race. This is indeed a racy
check, but inode_doinit_with_dentry() will recheck with isec->lock held.
Annotate the check with the data_race() macro to silence the KCSAN false
positive.
Reported-by: syzbot+319ed1769c0078257262@syzkaller.appspotmail.com
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Unfortunately it appears that vma_is_initial_heap() is currently broken
for applications that do not currently have any heap allocated, e.g.
brk == start_brk. The breakage is such that it will cause SELinux to
check for the process/execheap permission on memory regions that cross
brk/start_brk even when there is no heap.
The proper fix would be to correct vma_is_initial_heap(), but as there
are multiple callers I am hesitant to unilaterally modify the helper
out of concern that I would end up breaking some other subsystem. The
mm developers have been made aware of the situation and hopefully they
will have a fix at some point in the future, but we need a fix soon so
we are simply going to revert our use of vma_is_initial_heap() in favor
of our old logic/code which works as expected, even in the face of a
zero size heap. We can return to using vma_is_initial_heap() at some
point in the future when it is fixed.
Cc: stable@vger.kernel.org
Reported-by: Marc Reisner <reisner.marc@gmail.com>
Closes: https://lore.kernel.org/all/ZrPmoLKJEf1wiFmM@marcreisner.com
Fixes: 68df1baf158f ("selinux: use vma_is_initial_stack() and vma_is_initial_heap()")
Signed-off-by: Paul Moore <paul@paul-moore.com>
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To be consistent with most LSM hooks, convert the return value of
hook inode_copy_up_xattr to 0 or a negative error code.
Before:
- Hook inode_copy_up_xattr returns 0 when accepting xattr, 1 when
discarding xattr, -EOPNOTSUPP if it does not know xattr, or any
other negative error code otherwise.
After:
- Hook inode_copy_up_xattr returns 0 when accepting xattr, *-ECANCELED*
when discarding xattr, -EOPNOTSUPP if it does not know xattr, or
any other negative error code otherwise.
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>
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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>
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Move management of the perf_event->security blob out of the individual
security modules and into the security infrastructure. Instead of
allocating the blobs from within the modules the modules tell the
infrastructure how much space is required, and the space is allocated
there. There are no longer any modules that require the perf_event_free()
hook. The hook definition has been removed.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Move management of the infiniband security blob out of the individual
security modules and into the LSM infrastructure. The security modules
tell the infrastructure how much space they require at initialization.
There are no longer any modules that require the ib_free() hook.
The hook definition has been removed.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
[PM: subject tweak, selinux style fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Move management of the dev_tun security blob out of the individual
security modules and into the LSM infrastructure. The security modules
tell the infrastructure how much space they require at initialization.
There are no longer any modules that require the dev_tun_free hook.
The hook definition has been removed.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
[PM: subject tweak, selinux style fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Move management of the key->security blob out of the individual security
modules and into the security infrastructure. Instead of allocating the
blobs from within the modules the modules tell the infrastructure how
much space is required, and the space is allocated there. There are
no existing modules that require a key_free hook, so the call to it and
the definition for it have been removed.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Move management of the sock->sk_security blob out
of the individual security modules and into the security
infrastructure. Instead of allocating the blobs from within
the modules the modules tell the infrastructure how much
space is required, and the space is allocated there.
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Commit 61df7b828204 ("lsm: fixup the inode xattr capability handling")
moved the responsibility of doing the inode xattr capability checking
out of the individual LSMs and into the LSM framework itself.
Unfortunately, while the original commit added the capability checks
to both the setxattr and removexattr code in the LSM framework, it
only removed the setxattr capability checks from the individual LSMs,
leaving duplicated removexattr capability checks in both the SELinux
and Smack code.
This patch removes the duplicated code from SELinux and Smack.
Fixes: 61df7b828204 ("lsm: fixup the inode xattr capability handling")
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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The current security_inode_setxattr() and security_inode_removexattr()
hooks rely on individual LSMs to either call into the associated
capability hooks (cap_inode_setxattr() or cap_inode_removexattr()), or
return a magic value of 1 to indicate that the LSM layer itself should
perform the capability checks. Unfortunately, with the default return
value for these LSM hooks being 0, an individual LSM hook returning a
1 will cause the LSM hook processing to exit early, potentially
skipping a LSM. Thankfully, with the exception of the BPF LSM, none
of the LSMs which currently register inode xattr hooks should end up
returning a value of 1, and in the BPF LSM case, with the BPF LSM hooks
executing last there should be no real harm in stopping processing of
the LSM hooks. However, the reliance on the individual LSMs to either
call the capability hooks themselves, or signal the LSM with a return
value of 1, is fragile and relies on a specific set of LSMs being
enabled. This patch is an effort to resolve, or minimize, these
issues.
Before we discuss the solution, there are a few observations and
considerations that we need to take into account:
* BPF LSM registers an implementation for every LSM hook, and that
implementation simply returns the hook's default return value, a
0 in this case. We want to ensure that the default BPF LSM behavior
results in the capability checks being called.
* SELinux and Smack do not expect the traditional capability checks
to be applied to the xattrs that they "own".
* SELinux and Smack are currently written in such a way that the
xattr capability checks happen before any additional LSM specific
access control checks. SELinux does apply SELinux specific access
controls to all xattrs, even those not "owned" by SELinux.
* IMA and EVM also register xattr hooks but assume that the LSM layer
and specific LSMs have already authorized the basic xattr operation.
In order to ensure we perform the capability based access controls
before the individual LSM access controls, perform only one capability
access control check for each operation, and clarify the logic around
applying the capability controls, we need a mechanism to determine if
any of the enabled LSMs "own" a particular xattr and want to take
responsibility for controlling access to that xattr. The solution in
this patch is to create a new LSM hook, 'inode_xattr_skipcap', that is
not exported to the rest of the kernel via a security_XXX() function,
but is used by the LSM layer to determine if a LSM wants to control
access to a given xattr and avoid the traditional capability controls.
Registering an inode_xattr_skipcap hook is optional, if a LSM declines
to register an implementation, or uses an implementation that simply
returns the default value (0), there is no effect as the LSM continues
to enforce the capability based controls (unless another LSM takes
ownership of the xattr). If none of the LSMs signal that the
capability checks should be skipped, the capability check is performed
and if access is granted the individual LSM xattr access control hooks
are executed, keeping with the DAC-before-LSM convention.
Cc: stable@vger.kernel.org
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity updates from Mimi Zohar:
"Two IMA changes, one EVM change, a use after free bug fix, and a code
cleanup to address "-Wflex-array-member-not-at-end" warnings:
- The existing IMA {ascii, binary}_runtime_measurements lists include
a hard coded SHA1 hash. To address this limitation, define per TPM
enabled hash algorithm {ascii, binary}_runtime_measurements lists
- Close an IMA integrity init_module syscall measurement gap by
defining a new critical-data record
- Enable (partial) EVM support on stacked filesystems (overlayfs).
Only EVM portable & immutable file signatures are copied up, since
they do not contain filesystem specific metadata"
* tag 'integrity-v6.10' of ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: add crypto agility support for template-hash algorithm
evm: Rename is_unsupported_fs to is_unsupported_hmac_fs
fs: Rename SB_I_EVM_UNSUPPORTED to SB_I_EVM_HMAC_UNSUPPORTED
evm: Enforce signatures on unsupported filesystem for EVM_INIT_X509
ima: re-evaluate file integrity on file metadata change
evm: Store and detect metadata inode attributes changes
ima: Move file-change detection variables into new structure
evm: Use the metadata inode to calculate metadata hash
evm: Implement per signature type decision in security_inode_copy_up_xattr
security: allow finer granularity in permitting copy-up of security xattrs
ima: Rename backing_inode to real_inode
integrity: Avoid -Wflex-array-member-not-at-end warnings
ima: define an init_module critical data record
ima: Fix use-after-free on a dentry's dname.name
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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>
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Use the internal helper current_sid() where applicable.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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A number of small changes to selinux_lsm_getattr() to improve the
quality and readability of the code:
* Explicitly set the `value` parameter to NULL in the case where an
attribute has not been set.
* Rename the `__tsec` variable to `tsec` to better fit the SELinux code.
* Rename `bad` to `err_unlock` to better indicate the jump target drops
the RCU lock.
Signed-off-by: Paul Moore <paul@paul-moore.com>
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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>
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|
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
...
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux updates from Paul Moore:
"Really only a few notable changes:
- Continue the coding style/formatting fixup work
This is the bulk of the diffstat in this pull request, with the
focus this time around being the security/selinux/ss directory.
We've only got a couple of files left to cleanup and once we're
done with that we can start enabling some automatic style
verfication and introduce tooling to help new folks format their
code correctly.
- Don't restrict xattr copy-up when SELinux policy is not loaded
This helps systems that use overlayfs, or similar filesystems,
preserve their SELinux labels during early boot when the SELinux
policy has yet to be loaded.
- Reduce the work we do during inode initialization time
This isn't likely to show up in any benchmark results, but we
removed an unnecessary SELinux object class lookup/calculation
during inode initialization.
- Correct the return values in selinux_socket_getpeersec_dgram()
We had some inconsistencies with respect to our return values
across selinux_socket_getpeersec_dgram() and
selinux_socket_getpeersec_stream().
This provides a more uniform set of error codes across the two
functions and should help make it easier for users to identify
the source of a failure"
* tag 'selinux-pr-20240312' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: (24 commits)
selinux: fix style issues in security/selinux/ss/symtab.c
selinux: fix style issues in security/selinux/ss/symtab.h
selinux: fix style issues in security/selinux/ss/sidtab.c
selinux: fix style issues in security/selinux/ss/sidtab.h
selinux: fix style issues in security/selinux/ss/services.h
selinux: fix style issues in security/selinux/ss/policydb.c
selinux: fix style issues in security/selinux/ss/policydb.h
selinux: fix style issues in security/selinux/ss/mls_types.h
selinux: fix style issues in security/selinux/ss/mls.c
selinux: fix style issues in security/selinux/ss/mls.h
selinux: fix style issues in security/selinux/ss/hashtab.c
selinux: fix style issues in security/selinux/ss/hashtab.h
selinux: fix style issues in security/selinux/ss/ebitmap.c
selinux: fix style issues in security/selinux/ss/ebitmap.h
selinux: fix style issues in security/selinux/ss/context.h
selinux: fix style issues in security/selinux/ss/context.h
selinux: fix style issues in security/selinux/ss/constraint.h
selinux: fix style issues in security/selinux/ss/conditional.c
selinux: fix style issues in security/selinux/ss/conditional.h
selinux: fix style issues in security/selinux/ss/avtab.c
...
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Cross-merge networking fixes after downstream PR.
Conflicts:
net/mptcp/protocol.c
adf1bb78dab5 ("mptcp: fix snd_wnd initialization for passive socket")
9426ce476a70 ("mptcp: annotate lockless access for RX path fields")
https://lore.kernel.org/all/20240228103048.19255709@canb.auug.org.au/
Adjacent changes:
drivers/dpll/dpll_core.c
0d60d8df6f49 ("dpll: rely on rcu for netdev_dpll_pin()")
e7f8df0e81bf ("dpll: move xa_erase() call in to match dpll_pin_alloc() error path order")
drivers/net/veth.c
1ce7d306ea63 ("veth: try harder when allocating queue memory")
0bef512012b1 ("net: add netdev_lockdep_set_classes() to virtual drivers")
drivers/net/wireless/intel/iwlwifi/mvm/d3.c
8c9bef26e98b ("wifi: iwlwifi: mvm: d3: implement suspend with MLO")
78f65fbf421a ("wifi: iwlwifi: mvm: ensure offloading TID queue exists")
net/wireless/nl80211.c
f78c1375339a ("wifi: nl80211: reject iftype change with mesh ID change")
414532d8aa89 ("wifi: cfg80211: use IEEE80211_MAX_MESH_ID_LEN appropriately")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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selinux_getselfattr() doesn't properly initialize the string pointer
it passes to selinux_lsm_getattr() which can cause a problem when an
attribute hasn't been explicitly set; selinux_lsm_getattr() returns
0/success, but does not set or initialize the string label/attribute.
Failure to properly initialize the string causes problems later in
selinux_getselfattr() when the function attempts to kfree() the
string.
Cc: Casey Schaufler <casey@schaufler-ca.com>
Fixes: 762c934317e6 ("SELinux: Add selfattr hooks")
Suggested-by: Paul Moore <paul@paul-moore.com>
[PM: description changes as discussed in the thread]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Add the idmap parameter to the definition, so that evm_inode_setattr() can
be registered as this hook implementation.
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>
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Extended attribute copy-up functionality added via 19472b69d639d
("selinux: Implementation for inode_copy_up_xattr() hook") sees
"security.selinux" contexts dropped, instead relying on contexts
applied via the inode_copy_up() hook.
When copy-up takes place during early boot, prior to selinux
initialization / policy load, the context stripping can be unwanted
and unexpected.
With this change, filtering of "security.selinux" xattrs will only occur
after selinux initialization.
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Instead of returning -EINVAL if any type of error occurs, limit
-EINVAL to only those errors caused by passing a bad/invalid socket
or packet/skb. In other cases where everything is correct but there
isn't a valid peer label we return -ENOPROTOOPT.
This helps make selinux_socket_getpeersec_dgram() more consistent
with selinux_socket_getpeersec_stream().
Signed-off-by: Paul Moore <paul@paul-moore.com>
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We only need to call inode_mode_to_security_class() once in
selinux_inode_init_security().
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Utilize newly added bpf_token_create/bpf_token_free LSM hooks to
allocate struct bpf_security_struct for each BPF token object in
SELinux. This just follows similar pattern for BPF prog and map.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-18-andrii@kernel.org
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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
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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
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Pull io_uring updates from Jens Axboe:
"Mostly just come fixes and cleanups, but one feature as well. In
detail:
- Harden the check for handling IOPOLL based on return (Pavel)
- Various minor optimizations (Pavel)
- Drop remnants of SCM_RIGHTS fd passing support, now that it's no
longer supported since 6.7 (me)
- Fix for a case where bytes_done wasn't initialized properly on a
failure condition for read/write requests (me)
- Move the register related code to a separate file (me)
- Add support for returning the provided ring buffer head (me)
- Add support for adding a direct descriptor to the normal file table
(me, Christian Brauner)
- Fix for ensuring pending task_work for a ring with DEFER_TASKRUN is
run even if we timeout waiting (me)"
* tag 'for-6.8/io_uring-2024-01-08' of git://git.kernel.dk/linux:
io_uring: ensure local task_work is run on wait timeout
io_uring/kbuf: add method for returning provided buffer ring head
io_uring/rw: ensure io->bytes_done is always initialized
io_uring: drop any code related to SCM_RIGHTS
io_uring/unix: drop usage of io_uring socket
io_uring/register: move io_uring_register(2) related code to register.c
io_uring/openclose: add support for IORING_OP_FIXED_FD_INSTALL
io_uring/cmd: inline io_uring_cmd_get_task
io_uring/cmd: inline io_uring_cmd_do_in_task_lazy
io_uring: split out cmd api into a separate header
io_uring: optimise ltimeout for inline execution
io_uring: don't check iopoll if request completes
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Pull header cleanups from Kent Overstreet:
"The goal is to get sched.h down to a type only header, so the main
thing happening in this patchset is splitting out various _types.h
headers and dependency fixups, as well as moving some things out of
sched.h to better locations.
This is prep work for the memory allocation profiling patchset which
adds new sched.h interdepencencies"
* tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs: (51 commits)
Kill sched.h dependency on rcupdate.h
kill unnecessary thread_info.h include
Kill unnecessary kernel.h include
preempt.h: Kill dependency on list.h
rseq: Split out rseq.h from sched.h
LoongArch: signal.c: add header file to fix build error
restart_block: Trim includes
lockdep: move held_lock to lockdep_types.h
sem: Split out sem_types.h
uidgid: Split out uidgid_types.h
seccomp: Split out seccomp_types.h
refcount: Split out refcount_types.h
uapi/linux/resource.h: fix include
x86/signal: kill dependency on time.h
syscall_user_dispatch.h: split out *_types.h
mm_types_task.h: Trim dependencies
Split out irqflags_types.h
ipc: Kill bogus dependency on spinlock.h
shm: Slim down dependencies
workqueue: Split out workqueue_types.h
...
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull security module updates from Paul Moore:
- Add three new syscalls: lsm_list_modules(), lsm_get_self_attr(), and
lsm_set_self_attr().
The first syscall simply lists the LSMs enabled, while the second and
third get and set the current process' LSM attributes. Yes, these
syscalls may provide similar functionality to what can be found under
/proc or /sys, but they were designed to support multiple,
simultaneaous (stacked) LSMs from the start as opposed to the current
/proc based solutions which were created at a time when only one LSM
was allowed to be active at a given time.
We have spent considerable time discussing ways to extend the
existing /proc interfaces to support multiple, simultaneaous LSMs and
even our best ideas have been far too ugly to support as a kernel
API; after +20 years in the kernel, I felt the LSM layer had
established itself enough to justify a handful of syscalls.
Support amongst the individual LSM developers has been nearly
unanimous, with a single objection coming from Tetsuo (TOMOYO) as he
is worried that the LSM_ID_XXX token concept will make it more
difficult for out-of-tree LSMs to survive. Several members of the LSM
community have demonstrated the ability for out-of-tree LSMs to
continue to exist by picking high/unused LSM_ID values as well as
pointing out that many kernel APIs rely on integer identifiers, e.g.
syscalls (!), but unfortunately Tetsuo's objections remain.
My personal opinion is that while I have no interest in penalizing
out-of-tree LSMs, I'm not going to penalize in-tree development to
support out-of-tree development, and I view this as a necessary step
forward to support the push for expanded LSM stacking and reduce our
reliance on /proc and /sys which has occassionally been problematic
for some container users. Finally, we have included the linux-api
folks on (all?) recent revisions of the patchset and addressed all of
their concerns.
- Add a new security_file_ioctl_compat() LSM hook to handle the 32-bit
ioctls on 64-bit systems problem.
This patch includes support for all of the existing LSMs which
provide ioctl hooks, although it turns out only SELinux actually
cares about the individual ioctls. It is worth noting that while
Casey (Smack) and Tetsuo (TOMOYO) did not give explicit ACKs to this
patch, they did both indicate they are okay with the changes.
- Fix a potential memory leak in the CALIPSO code when IPv6 is disabled
at boot.
While it's good that we are fixing this, I doubt this is something
users are seeing in the wild as you need to both disable IPv6 and
then attempt to configure IPv6 labeled networking via
NetLabel/CALIPSO; that just doesn't make much sense.
Normally this would go through netdev, but Jakub asked me to take
this patch and of all the trees I maintain, the LSM tree seemed like
the best fit.
- Update the LSM MAINTAINERS entry with additional information about
our process docs, patchwork, bug reporting, etc.
I also noticed that the Lockdown LSM is missing a dedicated
MAINTAINERS entry so I've added that to the pull request. I've been
working with one of the major Lockdown authors/contributors to see if
they are willing to step up and assume a Lockdown maintainer role;
hopefully that will happen soon, but in the meantime I'll continue to
look after it.
- Add a handful of mailmap entries for Serge Hallyn and myself.
* tag 'lsm-pr-20240105' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (27 commits)
lsm: new security_file_ioctl_compat() hook
lsm: Add a __counted_by() annotation to lsm_ctx.ctx
calipso: fix memory leak in netlbl_calipso_add_pass()
selftests: remove the LSM_ID_IMA check in lsm/lsm_list_modules_test
MAINTAINERS: add an entry for the lockdown LSM
MAINTAINERS: update the LSM entry
mailmap: add entries for Serge Hallyn's dead accounts
mailmap: update/replace my old email addresses
lsm: mark the lsm_id variables are marked as static
lsm: convert security_setselfattr() to use memdup_user()
lsm: align based on pointer length in lsm_fill_user_ctx()
lsm: consolidate buffer size handling into lsm_fill_user_ctx()
lsm: correct error codes in security_getselfattr()
lsm: cleanup the size counters in security_getselfattr()
lsm: don't yet account for IMA in LSM_CONFIG_COUNT calculation
lsm: drop LSM_ID_IMA
LSM: selftests for Linux Security Module syscalls
SELinux: Add selfattr hooks
AppArmor: Add selfattr hooks
Smack: implement setselfattr and getselfattr hooks
...
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux updates from Paul Moore:
- Add a new SELinux initial SID, SECINITSID_INIT, to represent
userspace processes started before the SELinux policy is loaded in
early boot.
Prior to this patch all processes were marked as SECINITSID_KERNEL
before the SELinux policy was loaded, making it difficult to
distinquish early boot userspace processes from the kernel in the
SELinux policy.
For most users this will be a non-issue as the policy is loaded early
enough during boot, but for users who load their SELinux policy
relatively late, this should make it easier to construct meaningful
security policies.
- Cleanups to the selinuxfs code by Al, mostly on VFS related issues
during a policy reload.
The commit description has more detail, but the quick summary is that
we are replacing a disconnected directory approach with a temporary
directory that we swapover at the end of the reload.
- Fix an issue where the input sanity checking on socket bind()
operations was slightly different depending on the presence of
SELinux.
This is caused by the placement of the LSM hooks in the generic
socket layer as opposed to the protocol specific bind() handler where
the protocol specific sanity checks are performed. Mickaël has
mentioned that he is working to fix this, but in the meantime we just
ensure that we are replicating the checks properly.
We need to balance the placement of the LSM hooks with the number of
LSM hooks; pushing the hooks down into the protocol layers is likely
not the right answer.
- Update the avc_has_perm_noaudit() prototype to better match the
function definition.
- Migrate from using partial_name_hash() to full_name_hash() the
filename transition hash table.
This improves the quality of the code and has the potential for a
minor performance bump.
- Consolidate some open coded SELinux access vector comparisions into a
single new function, avtab_node_cmp(), and use that instead.
A small, but nice win for code quality and maintainability.
- Updated the SELinux MAINTAINERS entry with additional information
around process, bug reporting, etc.
We're also updating some of our "official" roles: dropping Eric Paris
and adding Ondrej as a reviewer.
- Cleanup the coding style crimes in security/selinux/include.
While I'm not a fan of code churn, I am pushing for more automated
code checks that can be done at the developer level and one of the
obvious things to check for is coding style.
In an effort to start from a "good" base I'm slowly working through
our source files cleaning them up with the help of clang-format and
good ol' fashioned human eyeballs; this has the first batch of these
changes.
I've been splitting the changes up per-file to help reduce the impact
if backports are required (either for LTS or distro kernels), and I
expect the some of the larger files, e.g. hooks.c and ss/services.c,
will likely need to be split even further.
- Cleanup old, outdated comments.
* tag 'selinux-pr-20240105' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: (24 commits)
selinux: Fix error priority for bind with AF_UNSPEC on PF_INET6 socket
selinux: fix style issues in security/selinux/include/initial_sid_to_string.h
selinux: fix style issues in security/selinux/include/xfrm.h
selinux: fix style issues in security/selinux/include/security.h
selinux: fix style issues with security/selinux/include/policycap_names.h
selinux: fix style issues in security/selinux/include/policycap.h
selinux: fix style issues in security/selinux/include/objsec.h
selinux: fix style issues with security/selinux/include/netlabel.h
selinux: fix style issues in security/selinux/include/netif.h
selinux: fix style issues in security/selinux/include/ima.h
selinux: fix style issues in security/selinux/include/conditional.h
selinux: fix style issues in security/selinux/include/classmap.h
selinux: fix style issues in security/selinux/include/avc_ss.h
selinux: align avc_has_perm_noaudit() prototype with definition
selinux: fix style issues in security/selinux/include/avc.h
selinux: fix style issues in security/selinux/include/audit.h
MAINTAINERS: drop Eric Paris from his SELinux role
MAINTAINERS: add Ondrej Mosnacek as a SELinux reviewer
selinux: remove the wrong comment about multithreaded process handling
selinux: introduce an initial SID for early boot processes
...
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The IPv6 network stack first checks the sockaddr length (-EINVAL error)
before checking the family (-EAFNOSUPPORT error).
This was discovered thanks to commit a549d055a22e ("selftests/landlock:
Add network tests").
Cc: Eric Paris <eparis@parisplace.org>
Cc: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Closes: https://lore.kernel.org/r/0584f91c-537c-4188-9e4f-04f192565667@collabora.com
Fixes: 0f8db8cc73df ("selinux: add AF_UNSPEC and INADDR_ANY checks to selinux_socket_bind()")
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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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>
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list_head is in types.h, not list.h., and the uapi header wasn't needed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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This code is rarely (never?) enabled by distros, and it hasn't caught
anything in decades. Let's kill off this legacy debug code.
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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linux/io_uring.h is slowly becoming a rubbish bin where we put
anything exposed to other subsystems. For instance, the task exit
hooks and io_uring cmd infra are completely orthogonal and don't need
each other's definitions. Start cleaning it up by splitting out all
command bits into a new header file.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7ec50bae6e21f371d3850796e716917fc141225a.1701391955.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Since commit d9250dea3f89 ("SELinux: add boundary support and thread
context assignment"), SELinux has been supporting assigning per-thread
security context under a constraint and the comment was updated
accordingly. However, seems like commit d84f4f992cbd ("CRED: Inaugurate
COW credentials") accidentally brought the old comment back that doesn't
match what the code does.
Considering the ease of understanding the code, this patch just removes the
wrong comment.
Fixes: d84f4f992cbd ("CRED: Inaugurate COW credentials")
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Currently, SELinux doesn't allow distinguishing between kernel threads
and userspace processes that are started before the policy is first
loaded - both get the label corresponding to the kernel SID. The only
way a process that persists from early boot can get a meaningful label
is by doing a voluntary dyntransition or re-executing itself.
Reusing the kernel label for userspace processes is problematic for
several reasons:
1. The kernel is considered to be a privileged domain and generally
needs to have a wide range of permissions allowed to work correctly,
which prevents the policy writer from effectively hardening against
early boot processes that might remain running unintentionally after
the policy is loaded (they represent a potential extra attack surface
that should be mitigated).
2. Despite the kernel being treated as a privileged domain, the policy
writer may want to impose certain special limitations on kernel
threads that may conflict with the requirements of intentional early
boot processes. For example, it is a good hardening practice to limit
what executables the kernel can execute as usermode helpers and to
confine the resulting usermode helper processes. However, a
(legitimate) process surviving from early boot may need to execute a
different set of executables.
3. As currently implemented, overlayfs remembers the security context of
the process that created an overlayfs mount and uses it to bound
subsequent operations on files using this context. If an overlayfs
mount is created before the SELinux policy is loaded, these "mounter"
checks are made against the kernel context, which may clash with
restrictions on the kernel domain (see 2.).
To resolve this, introduce a new initial SID (reusing the slot of the
former "init" initial SID) that will be assigned to any userspace
process started before the policy is first loaded. This is easy to do,
as we can simply label any process that goes through the
bprm_creds_for_exec LSM hook with the new init-SID instead of
propagating the kernel SID from the parent.
To provide backwards compatibility for existing policies that are
unaware of this new semantic of the "init" initial SID, introduce a new
policy capability "userspace_initial_context" and set the "init" SID to
the same context as the "kernel" SID unless this capability is set by
the policy.
Another small backwards compatibility measure is needed in
security_sid_to_context_core() for before the initial SELinux policy
load - see the code comment for explanation.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: edited comments based on feedback/discussion]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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As the kernel test robot helpfully reminded us, all of the lsm_id
instances defined inside the various LSMs should be marked as static.
The one exception is Landlock which uses its lsm_id variable across
multiple source files with an extern declaration in a header file.
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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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>
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