The patch titled
Subject: binfmt_elf: use vmalloc() for allocation of vma_filesz
has been added to the -mm tree. Its filename is
binfmt_elf-use-vmalloc-for-allocation-of-vma_filesz.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/binfmt_elf-use-vmalloc-for-allocation-of-vma_filesz.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/binfmt_elf-use-vmalloc-for-allocation-of-vma_filesz.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Jason Baron <jbaron@xxxxxxxxxx>
Subject: binfmt_elf: use vmalloc() for allocation of vma_filesz
We have observed page allocations failures of order 4 during core dump
while trying to allocate vma_filesz. This results in a useless core file
of size 0. To improve reliability use vmalloc().
Note that the vmalloc() allocation is bounded by sysctl_max_map_count,
which is 65,530 by default. So with a 4k page size, and 8 bytes per seg,
this is a max of 128 pages or an order 7 allocation. Other parts of the
core dump path, such as fill_files_note() are already using vmalloc() for
presumably similar reasons.
Link: http://lkml.kernel.org/r/1479745791-17611-1-git-send-email-jbaron@xxxxxxxxxx
Signed-off-by: Jason Baron <jbaron@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/binfmt_elf.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff -puN fs/binfmt_elf.c~binfmt_elf-use-vmalloc-for-allocation-of-vma_filesz fs/binfmt_elf.c
--- a/fs/binfmt_elf.c~binfmt_elf-use-vmalloc-for-allocation-of-vma_filesz
+++ a/fs/binfmt_elf.c
@@ -2204,7 +2204,9 @@ static int elf_core_dump(struct coredump
dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
- vma_filesz = kmalloc_array(segs - 1, sizeof(*vma_filesz), GFP_KERNEL);
+ if (segs - 1 > ULONG_MAX / sizeof(*vma_filesz))
+ goto end_coredump;
+ vma_filesz = vmalloc((segs - 1) * sizeof(*vma_filesz));
if (!vma_filesz)
goto end_coredump;
@@ -2311,7 +2313,7 @@ end_coredump:
cleanup:
free_note_info(&info);
kfree(shdr4extnum);
- kfree(vma_filesz);
+ vfree(vma_filesz);
kfree(phdr4note);
kfree(elf);
out:
_
Patches currently in -mm which might be from jbaron@xxxxxxxxxx are
binfmt_elf-use-vmalloc-for-allocation-of-vma_filesz.patch
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