Pull hardening fixes from Kees Cook:
- gcc plugins: Avoid Kconfig warnings with randstruct (Nathan
Chancellor)
- MAINTAINERS: Add security/Kconfig.hardening to hardening section
(Nathan Chancellor)
- MAINTAINERS: Add unsafe_memcpy() to the FORTIFY review list
* tag 'hardening-v6.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
MAINTAINERS: Add security/Kconfig.hardening to hardening section
hardening: Adjust dependencies in selection of MODVERSIONS
MAINTAINERS: Add unsafe_memcpy() to the FORTIFY review list
Pull lsm revert from Paul Moore:
"Here is the CONFIG_SECURITY_TOMOYO_LKM revert that we've been
discussing this week. With near unanimous agreement that the original
TOMOYO patches were not the right way to solve the distro problem
Tetsuo is trying the solve, reverting is our best option at this time"
* tag 'lsm-pr-20241004' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
tomoyo: revert CONFIG_SECURITY_TOMOYO_LKM support
This patch reverts two TOMOYO patches that were merged into Linus' tree
during the v6.12 merge window:
8b985bbfab ("tomoyo: allow building as a loadable LSM module")
268225a1de ("tomoyo: preparation step for building as a loadable LSM module")
Together these two patches introduced the CONFIG_SECURITY_TOMOYO_LKM
Kconfig build option which enabled a TOMOYO specific dynamic LSM loading
mechanism (see the original commits for more details). Unfortunately,
this approach was widely rejected by the LSM community as well as some
members of the general kernel community. Objections included concerns
over setting a bad precedent regarding individual LSMs managing their
LSM callback registrations as well as general kernel symbol exporting
practices. With little to no support for the CONFIG_SECURITY_TOMOYO_LKM
approach outside of Tetsuo, and multiple objections, we need to revert
these changes.
Link: https://lore.kernel.org/all/0c4b443a-9c72-4800-97e8-a3816b6a9ae2@I-love.SAKURA.ne.jp
Link: https://lore.kernel.org/all/CAHC9VhR=QjdoHG3wJgHFJkKYBg7vkQH2MpffgVzQ0tAByo_wRg@mail.gmail.com
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.
auto-generated by the following:
for i in `git grep -l -w asm/unaligned.h`; do
sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
MODVERSIONS recently grew a dependency on !COMPILE_TEST so that Rust
could be more easily tested. However, this introduces a Kconfig warning
when building allmodconfig with a clang version that supports RANDSTRUCT
natively because RANDSTRUCT_FULL and RANDSTRUCT_PERFORMANCE select
MODVERSIONS when MODULES is enabled, bypassing the !COMPILE_TEST
dependency:
WARNING: unmet direct dependencies detected for MODVERSIONS
Depends on [n]: MODULES [=y] && !COMPILE_TEST [=y]
Selected by [y]:
- RANDSTRUCT_FULL [=y] && (CC_HAS_RANDSTRUCT [=y] || GCC_PLUGINS [=n]) && MODULES [=y]
Add the !COMPILE_TEST dependency to the selections to clear up the
warning.
Fixes: 1f9c4a9967 ("Kbuild: make MODVERSIONS support depend on not being a compile test build")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240928-fix-randstruct-modversions-kconfig-warning-v1-1-27d3edc8571e@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
Pull tomoyo updates from Tetsuo Handa:
"One bugfix patch, one preparation patch, and one conversion patch.
TOMOYO is useful as an analysis tool for learning how a Linux system
works. My boss was hoping that SELinux's policy is generated from what
TOMOYO has observed. A translated paper describing it is available at
https://master.dl.sourceforge.net/project/tomoyo/docs/nsf2003-en.pdf/nsf2003-en.pdf?viasf=1
Although that attempt failed due to mapping problem between inode and
pathname, TOMOYO remains as an access restriction tool due to ability
to write custom policy by individuals.
I was delivering pure LKM version of TOMOYO (named AKARI) to users who
cannot afford rebuilding their distro kernels with TOMOYO enabled. But
since the LSM framework was converted to static calls, it became more
difficult to deliver AKARI to such users. Therefore, I decided to
update TOMOYO so that people can use mostly LKM version of TOMOYO with
minimal burden for both distributors and users"
* tag 'tomoyo-pr-20240927' of git://git.code.sf.net/p/tomoyo/tomoyo:
tomoyo: fallback to realpath if symlink's pathname does not exist
tomoyo: allow building as a loadable LSM module
tomoyo: preparation step for building as a loadable LSM module
Alfred Agrell found that TOMOYO cannot handle execveat(AT_EMPTY_PATH)
inside chroot environment where /dev and /proc are not mounted, for
commit 51f39a1f0c ("syscalls: implement execveat() system call") missed
that TOMOYO tries to canonicalize argv[0] when the filename fed to the
executed program as argv[0] is supplied using potentially nonexistent
pathname.
Since "/dev/fd/<fd>" already lost symlink information used for obtaining
that <fd>, it is too late to reconstruct symlink's pathname. Although
<filename> part of "/dev/fd/<fd>/<filename>" might not be canonicalized,
TOMOYO cannot use tomoyo_realpath_nofollow() when /dev or /proc is not
mounted. Therefore, fallback to tomoyo_realpath_from_path() when
tomoyo_realpath_nofollow() failed.
Reported-by: Alfred Agrell <blubban@gmail.com>
Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1082001
Fixes: 51f39a1f0c ("syscalls: implement execveat() system call")
Cc: stable@vger.kernel.org # v3.19+
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
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, ...)
Pull landlock updates from Mickaël Salaün:
"We can now scope a Landlock domain thanks to a new "scoped" field that
can deny interactions with resources outside of this domain.
The LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET flag denies connections to an
abstract UNIX socket created outside of the current scoped domain, and
the LANDLOCK_SCOPE_SIGNAL flag denies sending a signal to processes
outside of the current scoped domain.
These restrictions also apply to nested domains according to their
scope. The related changes will also be useful to support other kind
of IPC isolations"
* tag 'landlock-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
landlock: Document LANDLOCK_SCOPE_SIGNAL
samples/landlock: Add support for signal scoping
selftests/landlock: Test signal created by out-of-bound message
selftests/landlock: Test signal scoping for threads
selftests/landlock: Test signal scoping
landlock: Add signal scoping
landlock: Document LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET
samples/landlock: Add support for abstract UNIX socket scoping
selftests/landlock: Test inherited restriction of abstract UNIX socket
selftests/landlock: Test connected and unconnected datagram UNIX socket
selftests/landlock: Test UNIX sockets with any address formats
selftests/landlock: Test abstract UNIX socket scoping
selftests/landlock: Test handling of unknown scope
landlock: Add abstract UNIX socket scoping
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()
One of concerns for enabling TOMOYO in prebuilt kernels is that distributor
wants to avoid bloating kernel packages. Although boot-time kernel command
line options allows selecting built-in LSMs to enable, file size increase
of vmlinux and memory footprint increase of vmlinux caused by builtin-but-
not-enabled LSMs remains. If it becomes possible to make LSMs dynamically
appendable after boot using loadable kernel modules, these problems will
go away.
Another of concerns for enabling TOMOYO in prebuilt kernels is that who can
provide support when distributor cannot provide support. Due to "those who
compiled kernel code is expected to provide support for that kernel code"
spell, TOMOYO is failing to get enabled in Fedora distribution [1]. The
point of loadable kernel module is to share the workload. If it becomes
possible to make LSMs dynamically appendable after boot using loadable
kernel modules, as with people can use device drivers not supported by
distributors but provided by third party device vendors, we can break
this spell and can lower the barrier for using TOMOYO.
This patch is intended for demonstrating that there is nothing difficult
for supporting TOMOYO-like loadable LSM modules. For now we need to live
with a mixture of built-in part and loadable part because fully loadable
LSM modules are not supported since Linux 2.6.24 [2] and number of LSMs
which can reserve static call slots is determined at compile time in
Linux 6.12.
Major changes in this patch are described below.
There are no behavior changes as long as TOMOYO is built into vmlinux.
Add CONFIG_SECURITY_TOMOYO_LKM as "bool" instead of changing
CONFIG_SECURITY_TOMOYO from "bool" to "tristate", for something went
wrong with how Makefile is evaluated if I choose "tristate".
Add proxy.c for serving as a bridge between vmlinux and tomoyo.ko .
Move callback functions from init.c to proxy.c when building as a loadable
LSM module. init.c is built-in part and remains for reserving static call
slots. proxy.c contains module's init function and tells init.c location of
callback functions, making it possible to use static call for tomoyo.ko .
By deferring initialization of "struct tomoyo_task" until tomoyo.ko is
loaded, threads created between init.c reserved LSM hooks and proxy.c
updates LSM hooks will have NULL "struct tomoyo_task" instances. Assuming
that tomoyo.ko is loaded by the moment when the global init process starts,
initialize "struct tomoyo_task" instance for current thread as a kernel
thread when tomoyo_task(current) is called for the first time.
There is a hack for exporting currently not-exported functions.
This hack will be removed after all relevant functions are exported.
Link: https://bugzilla.redhat.com/show_bug.cgi?id=542986 [1]
Link: https://lkml.kernel.org/r/caafb609-8bef-4840-a080-81537356fc60@I-love.SAKURA.ne.jp [2]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Pull 'struct fd' updates from Al Viro:
"Just the 'struct fd' layout change, with conversion to accessor
helpers"
* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
add struct fd constructors, get rid of __to_fd()
struct fd: representation change
introduce fd_file(), convert all accessors to it.
In order to allow Makefile to generate tomoyo.ko as output, rename
tomoyo.c to hooks.h and cut out LSM hook registration part that will be
built into vmlinux from hooks.h to init.c . Also, update comments and
relocate some variables. No behavior changes.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Pull bpf updates from Alexei Starovoitov:
- Introduce '__attribute__((bpf_fastcall))' for helpers and kfuncs with
corresponding support in LLVM.
It is similar to existing 'no_caller_saved_registers' attribute in
GCC/LLVM with a provision for backward compatibility. It allows
compilers generate more efficient BPF code assuming the verifier or
JITs will inline or partially inline a helper/kfunc with such
attribute. bpf_cast_to_kern_ctx, bpf_rdonly_cast,
bpf_get_smp_processor_id are the first set of such helpers.
- Harden and extend ELF build ID parsing logic.
When called from sleepable context the relevants parts of ELF file
will be read to find and fetch .note.gnu.build-id information. Also
harden the logic to avoid TOCTOU, overflow, out-of-bounds problems.
- Improvements and fixes for sched-ext:
- Allow passing BPF iterators as kfunc arguments
- Make the pointer returned from iter_next method trusted
- Fix x86 JIT convergence issue due to growing/shrinking conditional
jumps in variable length encoding
- BPF_LSM related:
- Introduce few VFS kfuncs and consolidate them in
fs/bpf_fs_kfuncs.c
- Enforce correct range of return values from certain LSM hooks
- Disallow attaching to other LSM hooks
- Prerequisite work for upcoming Qdisc in BPF:
- Allow kptrs in program provided structs
- Support for gen_epilogue in verifier_ops
- Important fixes:
- Fix uprobe multi pid filter check
- Fix bpf_strtol and bpf_strtoul helpers
- Track equal scalars history on per-instruction level
- Fix tailcall hierarchy on x86 and arm64
- Fix signed division overflow to prevent INT_MIN/-1 trap on x86
- Fix get kernel stack in BPF progs attached to tracepoint:syscall
- Selftests:
- Add uprobe bench/stress tool
- Generate file dependencies to drastically improve re-build time
- Match JIT-ed and BPF asm with __xlated/__jited keywords
- Convert older tests to test_progs framework
- Add support for RISC-V
- Few fixes when BPF programs are compiled with GCC-BPF backend
(support for GCC-BPF in BPF CI is ongoing in parallel)
- Add traffic monitor
- Enable cross compile and musl libc
* tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (260 commits)
btf: require pahole 1.21+ for DEBUG_INFO_BTF with default DWARF version
btf: move pahole check in scripts/link-vmlinux.sh to lib/Kconfig.debug
btf: remove redundant CONFIG_BPF test in scripts/link-vmlinux.sh
bpf: Call the missed kfree() when there is no special field in btf
bpf: Call the missed btf_record_free() when map creation fails
selftests/bpf: Add a test case to write mtu result into .rodata
selftests/bpf: Add a test case to write strtol result into .rodata
selftests/bpf: Rename ARG_PTR_TO_LONG test description
selftests/bpf: Fix ARG_PTR_TO_LONG {half-,}uninitialized test
bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error
bpf: Improve check_raw_mode_ok test for MEM_UNINIT-tagged types
bpf: Fix helper writes to read-only maps
bpf: Remove truncation test in bpf_strtol and bpf_strtoul helpers
bpf: Fix bpf_strtol and bpf_strtoul helpers for 32bit
selftests/bpf: Add tests for sdiv/smod overflow cases
bpf: Fix a sdiv overflow issue
libbpf: Add bpf_object__token_fd accessor
docs/bpf: Add missing BPF program types to docs
docs/bpf: Add constant values for linkages
bpf: Use fake pt_regs when doing bpf syscall tracepoint tracing
...
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: 5f8d28f6d7 ("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>
Pull smack updates from Casey Schaufler:
"Two patches: one is a simple indentation correction, the other
corrects a potentially rcu unsafe pointer assignment"
* tag 'Smack-for-6.12' of https://github.com/cschaufler/smack-next:
smackfs: Use rcu_assign_pointer() to ensure safe assignment in smk_set_cipso
security: smack: Fix indentation in smack_netfilter.c
Currently, a sandbox process is not restricted to sending a signal (e.g.
SIGKILL) to a process outside the sandbox environment. The ability to
send a signal for a sandboxed process should be scoped the same way
abstract UNIX sockets are scoped. Therefore, we extend the "scoped"
field in a ruleset with LANDLOCK_SCOPE_SIGNAL to specify that a ruleset
will deny sending any signal from within a sandbox process to its parent
(i.e. any parent sandbox or non-sandboxed processes).
This patch adds file_set_fowner and file_free_security hooks to set and
release a pointer to the file owner's domain. This pointer, fown_domain
in landlock_file_security will be used in file_send_sigiotask to check
if the process can send a signal.
The ruleset_with_unknown_scope test is updated to support
LANDLOCK_SCOPE_SIGNAL.
This depends on two new changes:
- commit 1934b21261 ("file: reclaim 24 bytes from f_owner"): replace
container_of(fown, struct file, f_owner) with fown->file .
- commit 26f204380a ("fs: Fix file_set_fowner LSM hook
inconsistencies"): lock before calling the hook.
Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com>
Closes: https://github.com/landlock-lsm/linux/issues/8
Link: https://lore.kernel.org/r/df2b4f880a2ed3042992689a793ea0951f6798a5.1725657727.git.fahimitahera@gmail.com
[mic: Update landlock_get_current_domain()'s return type, improve and
fix locking in hook_file_set_fowner(), simplify and fix sleepable call
and locking issue in hook_file_send_sigiotask() and rebase on the latest
VFS tree, simplify hook_task_kill() and quickly return when not
sandboxed, improve comments, rename LANDLOCK_SCOPED_SIGNAL]
Co-developed-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
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
...
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
Pull procfs updates from Christian Brauner:
"This contains the following changes for procfs:
- Add config options and parameters to block forcing memory writes.
This adds a Kconfig option and boot param to allow removing the
FOLL_FORCE flag from /proc/<pid>/mem write calls as this can be
used in various attacks.
The traditional forcing behavior is kept as default because it can
break GDB and some other use cases.
This is the simpler version that you had requested.
- Restrict overmounting of ephemeral entities.
It is currently possible to mount on top of various ephemeral
entities in procfs. This specifically includes magic links. To
recap, magic links are links of the form /proc/<pid>/fd/<nr>. They
serve as references to a target file and during path lookup they
cause a jump to the target path. Such magic links disappear if the
corresponding file descriptor is closed.
Currently it is possible to overmount such magic links. This is
mostly interesting for an attacker that wants to somehow trick a
process into e.g., reopening something that it didn't intend to
reopen or to hide a malicious file descriptor.
But also it risks leaking mounts for long-running processes. When
overmounting a magic link like above, the mount will not be
detached when the file descriptor is closed. Only the target
mountpoint will disappear. Which has the consequence of making it
impossible to unmount that mount afterwards. So the mount will
stick around until the process exits and the /proc/<pid>/ directory
is cleaned up during proc_flush_pid() when the dentries are pruned
and invalidated.
That in turn means it's possible for a program to accidentally leak
mounts and it's also possible to make a task leak mounts without
it's knowledge if the attacker just keeps overmounting things under
/proc/<pid>/fd/<nr>.
Disallow overmounting of such ephemeral entities.
- Cleanup the readdir method naming in some procfs file operations.
- Replace kmalloc() and strcpy() with a simple kmemdup() call"
* tag 'vfs-6.12.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
proc: fold kmalloc() + strcpy() into kmemdup()
proc: block mounting on top of /proc/<pid>/fdinfo/*
proc: block mounting on top of /proc/<pid>/fd/*
proc: block mounting on top of /proc/<pid>/map_files/*
proc: add proc_splice_unmountable()
proc: proc_readfdinfo() -> proc_fdinfo_iterate()
proc: proc_readfd() -> proc_fd_iterate()
proc: add config & param to block forcing mem writes
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
...
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>
