linux/arch/sh/kernel
Linus Torvalds 1ec6574a3c This set of changes updates init and user mode helper tasks to be
ordinary user mode tasks.
 
 In commit 40966e316f ("kthread: Ensure struct kthread is present for
 all kthreads") caused init and the user mode helper threads that call
 kernel_execve to have struct kthread allocated for them.  This struct
 kthread going away during execve in turned made a use after free of
 struct kthread possible.
 
 The commit 343f4c49f2 ("kthread: Don't allocate kthread_struct for
 init and umh") is enough to fix the use after free and is simple enough
 to be backportable.
 
 The rest of the changes pass struct kernel_clone_args to clean things
 up and cause the code to make sense.
 
 In making init and the user mode helpers tasks purely user mode tasks
 I ran into two complications.  The function task_tick_numa was
 detecting tasks without an mm by testing for the presence of
 PF_KTHREAD.  The initramfs code in populate_initrd_image was using
 flush_delayed_fput to ensuere the closing of all it's file descriptors
 was complete, and flush_delayed_fput does not work in a userspace thread.
 
 I have looked and looked and more complications and in my code review
 I have not found any, and neither has anyone else with the code sitting
 in linux-next.
 
 Link: https://lkml.kernel.org/r/87mtfu4up3.fsf@email.froward.int.ebiederm.org
 
 Eric W. Biederman (8):
       kthread: Don't allocate kthread_struct for init and umh
       fork: Pass struct kernel_clone_args into copy_thread
       fork: Explicity test for idle tasks in copy_thread
       fork: Generalize PF_IO_WORKER handling
       init: Deal with the init process being a user mode process
       fork: Explicitly set PF_KTHREAD
       fork: Stop allowing kthreads to call execve
       sched: Update task_tick_numa to ignore tasks without an mm
 
  arch/alpha/kernel/process.c      | 13 ++++++------
  arch/arc/kernel/process.c        | 13 ++++++------
  arch/arm/kernel/process.c        | 12 ++++++-----
  arch/arm64/kernel/process.c      | 12 ++++++-----
  arch/csky/kernel/process.c       | 15 ++++++-------
  arch/h8300/kernel/process.c      | 10 ++++-----
  arch/hexagon/kernel/process.c    | 12 ++++++-----
  arch/ia64/kernel/process.c       | 15 +++++++------
  arch/m68k/kernel/process.c       | 12 ++++++-----
  arch/microblaze/kernel/process.c | 12 ++++++-----
  arch/mips/kernel/process.c       | 13 ++++++------
  arch/nios2/kernel/process.c      | 12 ++++++-----
  arch/openrisc/kernel/process.c   | 12 ++++++-----
  arch/parisc/kernel/process.c     | 18 +++++++++-------
  arch/powerpc/kernel/process.c    | 15 +++++++------
  arch/riscv/kernel/process.c      | 12 ++++++-----
  arch/s390/kernel/process.c       | 12 ++++++-----
  arch/sh/kernel/process_32.c      | 12 ++++++-----
  arch/sparc/kernel/process_32.c   | 12 ++++++-----
  arch/sparc/kernel/process_64.c   | 12 ++++++-----
  arch/um/kernel/process.c         | 15 +++++++------
  arch/x86/include/asm/fpu/sched.h |  2 +-
  arch/x86/include/asm/switch_to.h |  8 +++----
  arch/x86/kernel/fpu/core.c       |  4 ++--
  arch/x86/kernel/process.c        | 18 +++++++++-------
  arch/xtensa/kernel/process.c     | 17 ++++++++-------
  fs/exec.c                        |  8 ++++---
  include/linux/sched/task.h       |  8 +++++--
  init/initramfs.c                 |  2 ++
  init/main.c                      |  2 +-
  kernel/fork.c                    | 46 +++++++++++++++++++++++++++++++++-------
  kernel/sched/fair.c              |  2 +-
  kernel/umh.c                     |  6 +++---
  33 files changed, 234 insertions(+), 160 deletions(-)
 
 Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Merge tag 'kthread-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull kthread updates from Eric Biederman:
 "This updates init and user mode helper tasks to be ordinary user mode
  tasks.

  Commit 40966e316f ("kthread: Ensure struct kthread is present for
  all kthreads") caused init and the user mode helper threads that call
  kernel_execve to have struct kthread allocated for them. This struct
  kthread going away during execve in turned made a use after free of
  struct kthread possible.

  Here, commit 343f4c49f2 ("kthread: Don't allocate kthread_struct for
  init and umh") is enough to fix the use after free and is simple
  enough to be backportable.

  The rest of the changes pass struct kernel_clone_args to clean things
  up and cause the code to make sense.

  In making init and the user mode helpers tasks purely user mode tasks
  I ran into two complications. The function task_tick_numa was
  detecting tasks without an mm by testing for the presence of
  PF_KTHREAD. The initramfs code in populate_initrd_image was using
  flush_delayed_fput to ensuere the closing of all it's file descriptors
  was complete, and flush_delayed_fput does not work in a userspace
  thread.

  I have looked and looked and more complications and in my code review
  I have not found any, and neither has anyone else with the code
  sitting in linux-next"

* tag 'kthread-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  sched: Update task_tick_numa to ignore tasks without an mm
  fork: Stop allowing kthreads to call execve
  fork: Explicitly set PF_KTHREAD
  init: Deal with the init process being a user mode process
  fork: Generalize PF_IO_WORKER handling
  fork: Explicity test for idle tasks in copy_thread
  fork: Pass struct kernel_clone_args into copy_thread
  kthread: Don't allocate kthread_struct for init and umh
2022-06-03 16:03:05 -07:00
..
cpu sh: sq: use default_groups in kobj_type 2022-01-05 19:11:52 +01:00
syscalls arch: syscalls: simplify uapi/kapi directory creation 2022-03-31 12:03:46 +09:00
vsyscall mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
asm-offsets.c
crash_dump.c vmcore: convert copy_oldmem_page() to take an iov_iter 2022-04-29 14:37:59 -07:00
debugtraps.S
disassemble.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
dma-coherent.c dma-mapping: merge <linux/dma-noncoherent.h> into <linux/dma-map-ops.h> 2020-10-06 07:07:06 +02:00
dumpstack.c sh: stacktrace: Remove stacktrace_ops.stack() 2020-08-14 22:05:11 -04:00
dwarf.c
entry-common.S sh: fix syscall tracing 2020-09-13 21:22:55 -04:00
ftrace.c ftrace: Cleanup ftrace_dyn_arch_init() 2021-10-08 19:41:39 -04:00
head_32.S
hw_breakpoint.c sh: kernel: hw_breakpoint: Fix missing break in switch statement 2019-08-11 16:15:16 -05:00
idle.c sched/idle: Fix arch_cpu_idle() vs tracing 2020-11-24 16:47:35 +01:00
io_trapped.c sh: remove CONFIG_SET_FS support 2022-02-25 09:36:06 +01:00
io.c
iomap.c iomap: constify ioreadX() iomem argument (as in generic implementation) 2020-08-14 19:56:57 -07:00
ioport.c sh: don't include <asm/io_trapped.h> in <asm/io.h> 2020-08-14 22:05:16 -04:00
irq_32.c
irq.c softirq: Move do_softirq_own_stack() to generic asm header 2021-02-10 23:34:16 +01:00
kdebugfs.c
kgdb.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
kprobes.c kprobes: treewide: Make it harder to refer kretprobe_trampoline directly 2021-09-30 21:24:06 -04:00
machine_kexec.c mm: remove unneeded includes of <asm/pgalloc.h> 2020-08-07 11:33:26 -07:00
machvec.c Cleanup, SECCOMP_FILTER support, message printing fixes, and other 2020-08-15 18:50:32 -07:00
Makefile sh: remove -Werror from Makefiles 2020-08-14 22:05:13 -04:00
module.c sh: remove sh5 support 2020-06-01 14:48:52 -04:00
nmi_debug.c
perf_callchain.c sh: stacktrace: Remove stacktrace_ops.stack() 2020-08-14 22:05:11 -04:00
perf_event.c sh: Get rid of oprofile leftovers 2021-04-22 13:32:39 +01:00
process_32.c fork: Generalize PF_IO_WORKER handling 2022-05-07 09:01:59 -05:00
process.c sh: remove sh5 support 2020-06-01 14:48:52 -04:00
ptrace_32.c ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h 2022-03-10 13:35:08 -06:00
ptrace.c
reboot.c sh: Use do_kernel_power_off() 2022-05-19 19:30:31 +02:00
relocate_kernel.S
return_address.c
setup.c sh: convert to setup_initial_init_mm() 2021-07-08 11:48:21 -07:00
sh_bios.c
sh_ksyms_32.c sh: Add missing DECLARE_EXPORT() for __ashiftrt_r4_xx 2020-06-01 14:48:49 -04:00
signal_32.c resume_user_mode: Move to resume_user_mode.h 2022-03-10 16:51:50 -06:00
smp.c sched/core: Initialize the idle task with preemption disabled 2021-05-12 13:01:45 +02:00
stacktrace.c sh: stacktrace: Remove stacktrace_ops.stack() 2020-08-14 22:05:11 -04:00
swsusp.c
sys_sh32.c
sys_sh.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
syscalls_32.S
time.c sh: add the sh_ prefix to early platform symbols 2019-10-07 13:50:48 +02:00
topology.c drivers/base/node: consolidate node device subsystem initialization in node_dev_init() 2022-03-22 15:57:10 -07:00
traps_32.c sh: remove CONFIG_SET_FS support 2022-02-25 09:36:06 +01:00
traps.c exit: Add and use make_task_dead. 2021-12-13 12:04:45 -06:00
unwinder.c
vmlinux.lds.S vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG 2020-09-01 09:50:35 +02:00