Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH] mm: remap_file_pages: grab file ref to prevent race while mmaping | Date | Tue, 13 May 2014 23:35:42 -0400 |
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A file reference should be held while a file is mmaped, otherwise it might be freed while being used.
Suggested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> --- mm/mmap.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/mm/mmap.c b/mm/mmap.c index 2a0e0a8..da3c212 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2593,6 +2593,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, struct vm_area_struct *vma; unsigned long populate = 0; unsigned long ret = -EINVAL; + struct file *file; pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. " "See Documentation/vm/remap_file_pages.txt.\n", @@ -2636,8 +2637,10 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, munlock_vma_pages_range(vma, start, start + size); } + file = get_file(vma->vm_file); ret = do_mmap_pgoff(vma->vm_file, start, size, prot, flags, pgoff, &populate); + fput(file); out: up_write(&mm->mmap_sem); if (populate) -- 1.7.10.4
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