linux-stable.git/fs/binfmt_flat.c, branch v5.18

coredump: Don't compile flat_core_dump when coredumps are disabled

2022-03-09T16:37:07+00:00

Recently the kernel test robot reported:
> In file included from include/linux/kernel.h:29,
>                     from fs/binfmt_flat.c:21:
>    fs/binfmt_flat.c: In function 'flat_core_dump':
> >> fs/binfmt_flat.c:121:50: error: invalid use of undefined type 'struct coredump_params'
>      121 |                 current->comm, current->pid, cprm->siginfo->si_signo);
>          |                                                  ^~
>    include/linux/printk.h:418:33: note: in definition of macro 'printk_index_wrap'
>      418 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
>          |                                 ^~~~~~~~~~~
>    include/linux/printk.h:499:9: note: in expansion of macro 'printk'
>      499 |         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
>          |         ^~~~~~
>    fs/binfmt_flat.c:120:9: note: in expansion of macro 'pr_warn'
>      120 |         pr_warn("Process %s:%d received signr %d and should have core dumped\n",
>          |         ^~~~~~~
>    At top level:
>    fs/binfmt_flat.c:118:12: warning: 'flat_core_dump' defined but not used [-Wunused-function]
>      118 | static int flat_core_dump(struct coredump_params *cprm)
>          |            ^~~~~~~~~~~~~~

The little dinky do nothing function flat_core_dump has always been
compiled unconditionally.  With my change to move coredump_params into
coredump.h coredump_params reasonably becomes unavailable when
coredump support is not compiled in.  Fix this old issue by simply not
compiling flat_core_dump when coredump support is not supported.

Fixes: a99a3e2efaf1 ("coredump: Move definition of struct coredump_params into coredump.h")
Reported-by: kernel test robot 
Signed-off-by: "Eric W. Biederman"

coredump: Move definition of struct coredump_params into coredump.h

2022-03-08T18:50:58+00:00

Move the definition of struct coredump_params into coredump.h where
it belongs.

Remove the slightly errorneous comment explaining why struct
coredump_params was declared in binfmts.h.

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

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

binfmt_flat: allow not offsetting data start

2021-04-18T23:56:37+00:00

Commit 2217b9826246 ("binfmt_flat: revert "binfmt_flat: don't offset
the data start"") restored offsetting the start of the data section by
a number of words defined by MAX_SHARED_LIBS. As a result, since
MAX_SHARED_LIBS is never 0, a gap between the text and data sections
always exists. For architectures which cannot support a such gap
between the text and data sections (e.g. riscv nommu), flat binary
programs cannot be executed.

To allow an architecture to request no data start offset to allow for
contiguous text and data sections for binaries flagged with
FLAT_FLAG_RAM, introduce the new config option
CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET. Using this new option, the
macro DATA_START_OFFSET_WORDS is conditionally defined in binfmt_flat.c
to MAX_SHARED_LIBS for architectures tolerating or needing the data
start offset (CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET disabled case)
and to 0 when CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET is enabled.
DATA_START_OFFSET_WORDS is used in load_flat_file() to calculate the
data section length and start position.

Signed-off-by: Damien Le Moal 
Signed-off-by: Greg Ungerer

binfmt_flat: revert "binfmt_flat: don't offset the data start"

2020-08-23T22:49:13+00:00

binfmt_flat loader uses the gap between text and data to store data
segment pointers for the libraries. Even in the absence of shared
libraries it stores at least one pointer to the executable's own data
segment. Text and data can go back to back in the flat binary image and
without offsetting data segment last few instructions in the text
segment may get corrupted by the data segment pointer.

Fix it by reverting commit a2357223c50a ("binfmt_flat: don't offset the
data start").

Cc: stable@vger.kernel.org
Fixes: a2357223c50a ("binfmt_flat: don't offset the data start")
Signed-off-by: Max Filippov 
Signed-off-by: Greg Ungerer

Merge branch 'uaccess.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-06-10T23:02:54+00:00

Pull misc uaccess updates from Al Viro:
 "Assorted uaccess patches for this cycle - the stuff that didn't fit
  into thematic series"

* 'uaccess.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  bpf: make bpf_check_uarg_tail_zero() use check_zeroed_user()
  x86: kvm_hv_set_msr(): use __put_user() instead of 32bit __clear_user()
  user_regset_copyout_zero(): use clear_user()
  TEST_ACCESS_OK _never_ had been checked anywhere
  x86: switch cp_stat64() to unsafe_put_user()
  binfmt_flat: don't use __put_user()
  binfmt_elf_fdpic: don't use __... uaccess primitives
  binfmt_elf: don't bother with __{put,copy_to}_user()
  pselect6() and friends: take handling the combined 6th/7th args into helper

binfmt_flat: use flush_icache_user_range

2020-06-08T18:05:58+00:00

load_flat_file works on user addresses.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Acked-by: Greg Ungerer 
Cc: Alexander Viro 
Link: http://lkml.kernel.org/r/20200515143646.3857579-28-hch@lst.de
Signed-off-by: Linus Torvalds

binfmt_flat: don't use __put_user()

2020-06-03T20:58:53+00:00

... and check the return value

Signed-off-by: Al Viro

exec: Rename flush_old_exec begin_new_exec

2020-05-07T21:55:47+00:00

There is and has been for a very long time been a lot more going on in
flush_old_exec than just flushing the old state.  After the movement
of code from setup_new_exec there is a whole lot more going on than
just flushing the old executables state.

Rename flush_old_exec to begin_new_exec to more accurately reflect
what this function does.

Reviewed-by: Kees Cook 
Reviewed-by: Greg Ungerer 
Signed-off-by: "Eric W. Biederman"