The patch titled
Subject: mremap: don't leak new_vma if f_op->mremap() fails
has been added to the -mm tree. Its filename is
mremap-dont-leak-new_vma-if-f_op-mremap-fails.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mremap-dont-leak-new_vma-if-f_op-mremap-fails.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mremap-dont-leak-new_vma-if-f_op-mremap-fails.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: Oleg Nesterov <oleg@xxxxxxxxxx>
Subject: mremap: don't leak new_vma if f_op->mremap() fails
move_vma() can't just return if f_op->mremap() fails, we should unmap the
new vma like we do if move_page_tables() fails. To avoid the code
duplication this patch moves the "move entries back" under the new "if
(err)" branch.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Benjamin LaHaise <bcrl@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Kirill Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Cc: Laurent Dufour <ldufour@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mremap.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
diff -puN mm/mremap.c~mremap-dont-leak-new_vma-if-f_op-mremap-fails mm/mremap.c
--- a/mm/mremap.c~mremap-dont-leak-new_vma-if-f_op-mremap-fails
+++ a/mm/mremap.c
@@ -276,6 +276,12 @@ static unsigned long move_vma(struct vm_
moved_len = move_page_tables(vma, old_addr, new_vma, new_addr, old_len,
need_rmap_locks);
if (moved_len < old_len) {
+ err = -ENOMEM;
+ } else if (vma->vm_file && vma->vm_file->f_op->mremap) {
+ err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
+ }
+
+ if (unlikely(err)) {
/*
* On error, move entries back from new area to old,
* which will succeed since page tables still there,
@@ -286,16 +292,8 @@ static unsigned long move_vma(struct vm_
vma = new_vma;
old_len = new_len;
old_addr = new_addr;
- new_addr = -ENOMEM;
+ new_addr = err;
} else {
- if (vma->vm_file && vma->vm_file->f_op->mremap) {
- err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
- if (err < 0) {
- move_page_tables(new_vma, new_addr, vma,
- old_addr, moved_len, true);
- return err;
- }
- }
arch_remap(mm, old_addr, old_addr + old_len,
new_addr, new_addr + new_len);
}
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
mremap-dont-leak-new_vma-if-f_op-mremap-fails.patch
mm-move-mremap-from-file_operations-to-vm_operations_struct.patch
mremap-dont-do-mm_populatenew_addr-on-failure.patch
mremap-dont-do-uneccesary-checks-if-new_len-==-old_len.patch
mremap-simplify-the-overlap-check-in-mremap_to.patch
kmod-bunch-of-internal-functions-renames.patch
kmod-add-up-to-date-explanations-on-the-purpose-of-each-asynchronous-levels.patch
kmod-remove-unecessary-explicit-wide-cpu-affinity-setting.patch
linux-next.patch
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