The patch titled
Subject: coredump: fix spam with zero VMA process
has been added to the -mm tree. Its filename is
coredump-fix-spam-with-zero-vma-process.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/coredump-fix-spam-with-zero-vma-process.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/coredump-fix-spam-with-zero-vma-process.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Subject: coredump: fix spam with zero VMA process
Nobody ever tried to self destruct by unmapping whole address space at once:
munmap((void *)0, (1ULL << 47) - 4096);
Doing this produces 2 warnings for zero-length vmalloc allocations:
a.out[1353]: segfault at 7f80bcc4b757 ip 00007f80bcc4b757 sp 00007fff683939b8 error 14
a.out: vmalloc: allocation failure: 0 bytes, mode:0xcc0(GFP_KERNEL), nodemask=(null)
...
a.out: vmalloc: allocation failure: 0 bytes, mode:0xcc0(GFP_KERNEL), nodemask=(null)
...
Fix is to switch to kvmalloc().
Steps to reproduce:
// vsyscall=none
#include <sys/mman.h>
#include <sys/resource.h>
int main(void)
{
setrlimit(RLIMIT_CORE, &(struct rlimit){RLIM_INFINITY, RLIM_INFINITY});
munmap((void *)0, (1ULL << 47) - 4096);
return 0;
}
Link: http://lkml.kernel.org/r/20180410180353.GA2515@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/binfmt_elf.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff -puN fs/binfmt_elf.c~coredump-fix-spam-with-zero-vma-process fs/binfmt_elf.c
--- a/fs/binfmt_elf.c~coredump-fix-spam-with-zero-vma-process
+++ a/fs/binfmt_elf.c
@@ -1608,8 +1608,8 @@ static int fill_files_note(struct memelf
if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
return -EINVAL;
size = round_up(size, PAGE_SIZE);
- data = vmalloc(size);
- if (!data)
+ data = kvmalloc(size, GFP_KERNEL);
+ if (ZERO_OR_NULL_PTR(data))
return -ENOMEM;
start_end_ofs = data + 2;
@@ -1626,7 +1626,7 @@ static int fill_files_note(struct memelf
filename = file_path(file, name_curpos, remaining);
if (IS_ERR(filename)) {
if (PTR_ERR(filename) == -ENAMETOOLONG) {
- vfree(data);
+ kvfree(data);
size = size * 5 / 4;
goto alloc;
}
@@ -1919,7 +1919,7 @@ static void free_note_info(struct elf_no
kfree(t);
}
kfree(info->psinfo.data);
- vfree(info->files.data);
+ kvfree(info->files.data);
}
#else
@@ -2135,7 +2135,7 @@ static void free_note_info(struct elf_no
/* Free data possibly allocated by fill_files_note(): */
if (info->notes_files)
- vfree(info->notes_files->data);
+ kvfree(info->notes_files->data);
kfree(info->prstatus);
kfree(info->psinfo);
@@ -2281,8 +2281,8 @@ static int elf_core_dump(struct coredump
if (segs - 1 > ULONG_MAX / sizeof(*vma_filesz))
goto end_coredump;
- vma_filesz = vmalloc((segs - 1) * sizeof(*vma_filesz));
- if (!vma_filesz)
+ vma_filesz = kvmalloc((segs - 1) * sizeof(*vma_filesz), GFP_KERNEL);
+ if (ZERO_OR_NULL_PTR(vma_filesz))
goto end_coredump;
for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
@@ -2389,7 +2389,7 @@ end_coredump:
cleanup:
free_note_info(&info);
kfree(shdr4extnum);
- vfree(vma_filesz);
+ kvfree(vma_filesz);
kfree(phdr4note);
kfree(elf);
out:
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxx are
proc-do-less-stuff-under-pde_unload_lock.patch
proc-move-proc-sysvipc-creation-to-where-it-belongs.patch
proc-faster-open-close-of-files-without-release-hook.patch
proc-randomize-struct-pde_opener.patch
proc-move-struct-pde_opener-to-kmem-cache.patch
proc-account-struct-pde_opener.patch
proc-check-permissions-earlier-for-proc-wchan.patch
proc-use-set_puts-at-proc-wchan.patch
proc-test-proc-self-wchan.patch
proc-test-proc-self-syscall.patch
proc-move-struct-proc_dir_entry-into-kmem-cache.patch
proc-fix-proc-map_files-lookup-some-more.patch
proc-register-filesystem-last.patch
proc-faster-proc-cmdline.patch
proc-do-mmput-asap-for-proc-map_files.patch
proc-revalidate-misc-dentries.patch
proc-test-last-field-of-proc-loadavg.patch
proc-reject-and-as-filenames.patch
proc-switch-struct-proc_dir_entry-count-to-refcount.patch
proc-shotgun-test-read-readdir-readlink-a-little-write.patch
proc-shotgun-test-read-readdir-readlink-a-little-write-fix.patch
proc-shotgun-test-read-readdir-readlink-a-little-write-fix-2.patch
proc-use-slower-rb_first.patch
proc-test-proc-uptime.patch
uts-create-struct-uts_namespace-from-kmem_cache.patch
coredump-fix-spam-with-zero-vma-process.patch
seq_file-allocate-seq_file-from-kmem_cache.patch
seq_file-account-everything.patch
seq_file-delete-small-value-optimization.patch
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