linux-toradex.git/fs/binfmt_elf_fdpic.c, branch v6.4-rc5

ELF: fix all "Elf" typos

2023-04-08T20:45:37+00:00

ELF is acronym and therefore should be spelled in all caps.

I left one exception at Documentation/arm/nwfpe/nwfpe.rst which looks like
being written in the first person.

Link: https://lkml.kernel.org/r/Y/3wGWQviIOkyLJW@p183
Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton

elfcore: Add a cprm parameter to elf_core_extra_{phdrs,data_size}

2023-01-05T15:12:12+00:00

A subsequent fix for arm64 will use this parameter to parse the vma
information from the snapshot created by dump_vma_snapshot() rather than
traversing the vma list without the mmap_lock.

Fixes: 6dd8b1a0b6cb ("arm64: mte: Dump the MTE tags in the core file")
Cc:  # 5.18.x
Signed-off-by: Catalin Marinas 
Reported-by: Seth Jenkins 
Suggested-by: Seth Jenkins 
Cc: Will Deacon 
Cc: Eric Biederman 
Cc: Kees Cook 
Link: https://lore.kernel.org/r/20221222181251.1345752-3-catalin.marinas@arm.com
Signed-off-by: Will Deacon

binfmt: Fix error return code in load_elf_fdpic_binary()

2022-12-02T03:15:52+00:00

Fix to return a negative error code from create_elf_fdpic_tables()
instead of 0.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Wang Yufen 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/1669945261-30271-1-git-send-email-wangyufen@huawei.com

binfmt: Fix whitespace issues

2022-10-25T22:17:23+00:00

Fix the annoying whitespace issues that have been following these files
around for years.

Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Kees Cook 
Acked-by: Christian Brauner (Microsoft) 
Link: https://lore.kernel.org/r/20221018071350.never.230-kees@kernel.org

coredump: Snapshot the vmas in do_coredump

2022-03-08T18:55:29+00:00

Move the call of dump_vma_snapshot and kvfree(vma_meta) out of the
individual coredump routines into do_coredump itself.  This makes
the code less error prone and easier to maintain.

Make the vma snapshot available to the coredump routines
in struct coredump_params.  This makes it easier to
change and update what is captures in the vma snapshot
and will be needed for fixing fill_file_notes.

Reviewed-by: Jann Horn 
Reviewed-by: Kees Cook 
Signed-off-by: "Eric W. Biederman"

binfmt: move more stuff undef CONFIG_COREDUMP

2022-03-02T00:16:27+00:00

struct linux_binfmt::core_dump and struct min_coredump::min_coredump
are used under CONFIG_COREDUMP only. Shrink those embedded configs
a bit.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/YglbIFyN+OtwVyjW@localhost.localdomain

coredump: Limit coredumps to a single thread group

2021-10-08T17:06:02+00:00

Today when a signal is delivered with a handler of SIG_DFL whose
default behavior is to generate a core dump not only that process but
every process that shares the mm is killed.

In the case of vfork this looks like a real world problem.  Consider
the following well defined sequence.

	if (vfork() == 0) {
		execve(...);
		_exit(EXIT_FAILURE);
	}

If a signal that generates a core dump is received after vfork but
before the execve changes the mm the process that called vfork will
also be killed (as the mm is shared).

Similarly if the execve fails after the point of no return the kernel
delivers SIGSEGV which will kill both the exec'ing process and because
the mm is shared the process that called vfork as well.

As far as I can tell this behavior is a violation of people's
reasonable expectations, POSIX, and is unnecessarily fragile when the
system is low on memory.

Solve this by making a userspace visible change to only kill a single
process/thread group.  This is possible because Jann Horn recently
modified[1] the coredump code so that the mm can safely be modified
while the coredump is happening.  With LinuxThreads long gone I don't
expect anyone to have a notice this behavior change in practice.

To accomplish this move the core_state pointer from mm_struct to
signal_struct, which allows different thread groups to coredump
simultatenously.

In zap_threads remove the work to kill anything except for the current
thread group.

v2: Remove core_state from the VM_BUG_ON_MM print to fix
    compile failure when CONFIG_DEBUG_VM is enabled.
    Reported-by: Stephen Rothwell 

[1] a07279c9a8cd ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot")
Fixes: d89f3847def4 ("[PATCH] thread-aware coredumps, 2.5.43-C3")
History-tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Link: https://lkml.kernel.org/r/87y27mvnke.fsf@disp2133
Link: https://lkml.kernel.org/r/20211007144701.67592574@canb.auug.org.au
Reviewed-by: Kees Cook 
Signed-off-by: "Eric W. Biederman"

binfmt: remove in-tree usage of MAP_DENYWRITE

2021-09-03T16:42:01+00:00

At exec time when we mmap the new executable via MAP_DENYWRITE we have it
opened via do_open_execat() and already deny_write_access()'ed the file
successfully. Once exec completes, we allow_write_acces(); however,
we set mm->exe_file in begin_new_exec() via set_mm_exe_file() and
also deny_write_access() as long as mm->exe_file remains set. We'll
effectively deny write access to our executable via mm->exe_file
until mm->exe_file is changed -- when the process is removed, on new
exec, or via sys_prctl(PR_SET_MM_MAP/EXE_FILE).

Let's remove all usage of MAP_DENYWRITE, it's no longer necessary for
mm->exe_file.

In case of an elf interpreter, we'll now only deny write access to the file
during exec. This is somewhat okay, because the interpreter behaves
(and sometime is) a shared library; all shared libraries, especially the
ones loaded directly in user space like via dlopen() won't ever be mapped
via MAP_DENYWRITE, because we ignore that from user space completely;
these shared libraries can always be modified while mapped and executed.
Let's only special-case the main executable, denying write access while
being executed by a process. This can be considered a minor user space
visible change.

While this is a cleanup, it also fixes part of a problem reported with
VM_DENYWRITE on overlayfs, as VM_DENYWRITE is effectively unused with
this patch and will be removed next:
  "Overlayfs did not honor positive i_writecount on realfile for
   VM_DENYWRITE mappings." [1]

[1] https://lore.kernel.org/r/YNHXzBgzRrZu1MrD@miu.piliscsaba.redhat.com/

Reported-by: Chengguang Xu 
Acked-by: "Eric W. Biederman" 
Acked-by: Christian König 
Signed-off-by: David Hildenbrand

Merge branch 'akpm' (patches from Andrew)

2021-06-30T00:29:11+00:00

Merge misc updates from Andrew Morton:
 "191 patches.

  Subsystems affected by this patch series: kthread, ia64, scripts,
  ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab,
  slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap,
  mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization,
  pagealloc, and memory-failure)"

* emailed patches from Andrew Morton : (191 commits)
  mm,hwpoison: make get_hwpoison_page() call get_any_page()
  mm,hwpoison: send SIGBUS with error virutal address
  mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes
  mm/page_alloc: allow high-order pages to be stored on the per-cpu lists
  mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM
  mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
  docs: remove description of DISCONTIGMEM
  arch, mm: remove stale mentions of DISCONIGMEM
  mm: remove CONFIG_DISCONTIGMEM
  m68k: remove support for DISCONTIGMEM
  arc: remove support for DISCONTIGMEM
  arc: update comment about HIGHMEM implementation
  alpha: remove DISCONTIGMEM and NUMA
  mm/page_alloc: move free_the_page
  mm/page_alloc: fix counting of managed_pages
  mm/page_alloc: improve memmap_pages dbg msg
  mm: drop SECTION_SHIFT in code comments
  mm/page_alloc: introduce vm.percpu_pagelist_high_fraction
  mm/page_alloc: limit the number of pages on PCP lists when reclaim is active
  mm/page_alloc: scale the number of pages that are batch freed
  ...

binfmt: remove in-tree usage of MAP_EXECUTABLE

2021-06-29T17:53:50+00:00

Ever since commit e9714acf8c43 ("mm: kill vma flag VM_EXECUTABLE and
mm->num_exe_file_vmas"), VM_EXECUTABLE is gone and MAP_EXECUTABLE is
essentially completely ignored.  Let's remove all usage of MAP_EXECUTABLE.

[akpm@linux-foundation.org: fix blooper in fs/binfmt_aout.c. per David]

Link: https://lkml.kernel.org/r/20210421093453.6904-3-david@redhat.com
Signed-off-by: David Hildenbrand 
Acked-by: "Eric W. Biederman" 
Reviewed-by: Kees Cook 
Cc: Alexander Shishkin 
Cc: Alexander Viro 
Cc: Arnaldo Carvalho de Melo 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Don Zickus 
Cc: Feng Tang 
Cc: Greg Ungerer 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kevin Brodsky 
Cc: Mark Rutland 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds