debug_input_flush_fn() always copies one byte from the userspace buffer
with copy_from_user() regardless of the supplied write length. A
zero-length write therefore reads one byte beyond the caller's buffer.
If the stale byte happens to be '-' or a digit the debug log is
silently flushed. With an unmapped buffer the call returns -EFAULT.

Reject zero-length writes before copying from userspace.

Cc: stable@vger.kernel.org # v5.10+
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

debug_get_user_string() duplicates the userspace buffer with
memdup_user_nul() and then unconditionally looks at buffer[user_len - 1]
to strip a trailing newline.

A zero-length write reaches this helper unchanged, so the newline trim
reads before the start of the allocated buffer.

Reject empty writes before accessing the last input byte.

Fixes: 66a464dbc8e0 ("[PATCH] s390: debug feature changes")
Cc: stable@vger.kernel.org
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20260417073530.96002-1-pengpeng@iscas.ac.cn
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

Pull integrity updates from Mimi Zohar:
 "There are two main changes, one feature removal, some code cleanup,
  and a number of bug fixes.

  Main changes:
   - Detecting secure boot mode was limited to IMA. Make detecting
     secure boot mode accessible to EVM and other LSMs
   - IMA sigv3 support was limited to fsverity. Add IMA sigv3 support
     for IMA regular file hashes and EVM portable signatures

  Remove:
   - Remove IMA support for asychronous hash calculation originally
     added for hardware acceleration

  Cleanup:
   - Remove unnecessary Kconfig CONFIG_MODULE_SIG and CONFIG_KEXEC_SIG
     tests
   - Add descriptions of the IMA atomic flags

  Bug fixes:
   - Like IMA, properly limit EVM "fix" mode
   - Define and call evm_fix_hmac() to update security.evm
   - Fallback to using i_version to detect file change for filesystems
     that do not support STATX_CHANGE_COOKIE
   - Address missing kernel support for configured (new) TPM hash
     algorithms
   - Add missing crypto_shash_final() return value"

* tag 'integrity-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  evm: Enforce signatures version 3 with new EVM policy 'bit 3'
  integrity: Allow sigv3 verification on EVM_XATTR_PORTABLE_DIGSIG
  ima: add support to require IMA sigv3 signatures
  ima: add regular file data hash signature version 3 support
  ima: Define asymmetric_verify_v3() to verify IMA sigv3 signatures
  ima: remove buggy support for asynchronous hashes
  integrity: Eliminate weak definition of arch_get_secureboot()
  ima: Add code comments to explain IMA iint cache atomic_flags
  ima_fs: Correctly create securityfs files for unsupported hash algos
  ima: check return value of crypto_shash_final() in boot aggregate
  ima: Define and use a digest_size field in the ima_algo_desc structure
  powerpc/ima: Drop unnecessary check for CONFIG_MODULE_SIG
  ima: efi: Drop unnecessary check for CONFIG_MODULE_SIG/CONFIG_KEXEC_SIG
  ima: fallback to using i_version to detect file change
  evm: fix security.evm for a file with IMA signature
  s390: Drop unnecessary CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT
  evm: Don't enable fix mode when secure boot is enabled
  integrity: Make arch_ima_get_secureboot integrity-wide

Pull bpf updates from Alexei Starovoitov:

 - Welcome new BPF maintainers: Kumar Kartikeya Dwivedi, Eduard
   Zingerman while Martin KaFai Lau reduced his load to Reviwer.

 - Lots of fixes everywhere from many first time contributors. Thank you
   All.

 - Diff stat is dominated by mechanical split of verifier.c into
   multiple components:

    - backtrack.c: backtracking logic and jump history
    - states.c:    state equivalence
    - cfg.c:       control flow graph, postorder, strongly connected
                   components
    - liveness.c:  register and stack liveness
    - fixups.c:    post-verification passes: instruction patching, dead
                   code removal, bpf_loop inlining, finalize fastcall

   8k line were moved. verifier.c still stands at 20k lines.

   Further refactoring is planned for the next release.

 - Replace dynamic stack liveness with static stack liveness based on
   data flow analysis.

   This improved the verification time by 2x for some programs and
   equally reduced memory consumption. New logic is in liveness.c and
   supported by constant folding in const_fold.c (Eduard Zingerman,
   Alexei Starovoitov)

 - Introduce BTF layout to ease addition of new BTF kinds (Alan Maguire)

 - Use kmalloc_nolock() universally in BPF local storage (Amery Hung)

 - Fix several bugs in linked registers delta tracking (Daniel Borkmann)

 - Improve verifier support of arena pointers (Emil Tsalapatis)

 - Improve verifier tracking of register bounds in min/max and tnum
   domains (Harishankar Vishwanathan, Paul Chaignon, Hao Sun)

 - Further extend support for implicit arguments in the verifier (Ihor
   Solodrai)

 - Add support for nop,nop5 instruction combo for USDT probes in libbpf
   (Jiri Olsa)

 - Support merging multiple module BTFs (Josef Bacik)

 - Extend applicability of bpf_kptr_xchg (Kaitao Cheng)

 - Retire rcu_trace_implies_rcu_gp() (Kumar Kartikeya Dwivedi)

 - Support variable offset context access for 'syscall' programs (Kumar
   Kartikeya Dwivedi)

 - Migrate bpf_task_work and dynptr to kmalloc_nolock() (Mykyta
   Yatsenko)

 - Fix UAF in in open-coded task_vma iterator (Puranjay Mohan)

* tag 'bpf-next-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (241 commits)
  selftests/bpf: cover short IPv4/IPv6 inputs with adjust_room
  bpf: reject short IPv4/IPv6 inputs in bpf_prog_test_run_skb
  selftests/bpf: Use memfd_create instead of shm_open in cgroup_iter_memcg
  selftests/bpf: Add test for cgroup storage OOB read
  bpf: Fix OOB in pcpu_init_value
  selftests/bpf: Fix reg_bounds to match new tnum-based refinement
  selftests/bpf: Add tests for non-arena/arena operations
  bpf: Allow instructions with arena source and non-arena dest registers
  bpftool: add missing fsession to the usage and docs of bpftool
  docs/bpf: add missing fsession attach type to docs
  bpf: add missing fsession to the verifier log
  bpf: Move BTF checking logic into check_btf.c
  bpf: Move backtracking logic to backtrack.c
  bpf: Move state equivalence logic to states.c
  bpf: Move check_cfg() into cfg.c
  bpf: Move compute_insn_live_regs() into liveness.c
  bpf: Move fixup/post-processing logic from verifier.c into fixups.c
  bpf: Simplify do_check_insn()
  bpf: Move checks for reserved fields out of the main pass
  bpf: Delete unused variable
  ...

Pull module updates from Sami Tolvanen:
 "Kernel symbol flags:

   - Replace the separate *_gpl symbol sections (__ksymtab_gpl and
     __kcrctab_gpl) with a unified symbol table and a new __kflagstab
     section.

     This section stores symbol flags, such as the GPL-only flag, as an
     8-bit bitset for each exported symbol. This is a cleanup that
     simplifies symbol lookup in the module loader by avoiding table
     fragmentation and will allow a cleaner way to add more flags later
     if needed.

  Module signature UAPI:

   - Move struct module_signature to the UAPI headers to allow reuse by
     tools outside the kernel proper, such as kmod and
     scripts/sign-file.

     This also renames a few constants for clarity and drops unused
     signature types as preparation for hash-based module integrity
     checking work that's in progress.

  Sysfs:

   - Add a /sys/module/<module>/import_ns sysfs attribute to show the
     symbol namespaces imported by loaded modules.

     This makes it easier to verify driver API access at runtime on
     systems that care about such things (e.g. Android).

  Cleanups and fixes:

   - Force sh_addr to 0 for all sections in module.lds. This prevents
     non-zero section addresses when linking modules with 'ld.bfd -r',
     which confused elfutils.

   - Fix a memory leak of charp module parameters on module unload when
     the kernel is configured with CONFIG_SYSFS=n.

   - Override the -EEXIST error code returned by module_init() to
     userspace. This prevents confusion with the errno reserved by the
     module loader to indicate that a module is already loaded.

   - Simplify the warning message and drop the stack dump on positive
     returns from module_init().

   - Drop unnecessary extern keywords from function declarations and
     synchronize parse_args() arguments with their implementation"

* tag 'modules-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux: (23 commits)
  module: Simplify warning on positive returns from module_init()
  module: Override -EEXIST module return
  documentation: remove references to *_gpl sections
  module: remove *_gpl sections from vmlinux and modules
  module: deprecate usage of *_gpl sections in module loader
  module: use kflagstab instead of *_gpl sections
  module: populate kflagstab in modpost
  module: add kflagstab section to vmlinux and modules
  module: define ksym_flags enumeration to represent kernel symbol flags
  selftests/bpf: verify_pkcs7_sig: Use 'struct module_signature' from the UAPI headers
  sign-file: use 'struct module_signature' from the UAPI headers
  tools uapi headers: add linux/module_signature.h
  module: Move 'struct module_signature' to UAPI
  module: Give MODULE_SIG_STRING a more descriptive name
  module: Give 'enum pkey_id_type' a more specific name
  module: Drop unused signature types
  extract-cert: drop unused definition of PKEY_ID_PKCS7
  docs: symbol-namespaces: mention sysfs attribute
  module: expose imported namespaces via sysfs
  module: Remove extern keyword from param prototypes
  ...

Pull hardening updates from Kees Cook:

 - randomize_kstack: Improve implementation across arches (Ryan Roberts)

 - lkdtm/fortify: Drop unneeded FORTIFY_STR_OBJECT test

 - refcount: Remove unused __signed_wrap function annotations

* tag 'hardening-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  lkdtm/fortify: Drop unneeded FORTIFY_STR_OBJECT test
  refcount: Remove unused __signed_wrap function annotations
  randomize_kstack: Unify random source across arches
  randomize_kstack: Maintain kstack_offset per task

Pull s390 fixes from Vasily Gorbik:

 - Fix a memory leak in the zcrypt driver where the AP message buffer
   for clear key RSA requests was allocated twice, once by the caller
   and again locally, causing the first allocation to never be freed

 - Fix the cpum_sf perf sampling rate overflow adjustment to clamp the
   recalculated rate to the hardware maximum, preventing exceptions on
   heavily loaded systems running with HZ=1000

* tag 's390-7.0-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/zcrypt: Fix memory leak with CCA cards used as accelerator
  s390/cpum_sf: Cap sampling rate to prevent lsctl exception

Cross-merge BPF and other fixes after downstream PR.

Minor conflict in kernel/bpf/verifier.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Pull s390 fixes from Vasily Gorbik:

 - Add array_index_nospec() to syscall dispatch table lookup to prevent
   limited speculative out-of-bounds access with user-controlled syscall
   number

 - Mark array_index_mask_nospec() __always_inline since GCC may emit an
   out-of-line call instead of the inline data dependency sequence the
   mitigation relies on

 - Clear r12 on kernel entry to prevent potential speculative use of
   user value in system_call, ext/io/mcck interrupt handlers

* tag 's390-7.0-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/entry: Scrub r12 register on kernel entry
  s390/syscalls: Add spectre boundary for syscall dispatch table
  s390/barrier: Make array_index_mask_nospec() __always_inline

Before commit f33f2d4c7c80 ("s390/bp: remove TIF_ISOLATE_BP"),
all entry handlers loaded r12 with the current task pointer
(lg %r12,__LC_CURRENT) for use by the BPENTER/BPEXIT macros. That
commit removed TIF_ISOLATE_BP, dropping both the branch prediction
macros and the r12 load, but did not add r12 to the register clearing
sequence.

Add the missing xgr %r12,%r12 to make the register scrub consistent
across all entry points.

Fixes: f33f2d4c7c80 ("s390/bp: remove TIF_ISOLATE_BP")
Cc: stable@kernel.org
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>