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From: Brian Geffon To: Andrew Morton Cc: "Michael S . Tsirkin" , Brian Geffon , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrea Arcangeli , Sonny Rao , Minchan Kim , Joel Fernandes , "Kirill A . Shutemov" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: A user is not required to set a new address when using MREMAP_DONTUNMAP as it can be used without MREMAP_FIXED. When doing so the remap event will use new_addr which may not have been set and we didn't propagate it back other then in the return value of remap_to. Because ret is always the new address it's probably more correct to use it rather than new_addr on the remap_event_complete call, and it resolves this bug. Signed-off-by: Brian Geffon --- mm/mremap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/mremap.c b/mm/mremap.c index c881abeba0bf..6aa6ea605068 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -794,7 +794,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, if (locked && new_len > old_len) mm_populate(new_addr + old_len, new_len - old_len); userfaultfd_unmap_complete(mm, &uf_unmap_early); - mremap_userfaultfd_complete(&uf, addr, new_addr, old_len); + mremap_userfaultfd_complete(&uf, addr, ret, old_len); userfaultfd_unmap_complete(mm, &uf_unmap); return ret; }