Messages in this thread Patch in this message | | | From | Mike Rapoport <> | Subject | [PATCH] userfaultfd_zeropage: return -ENOSPC in case mm has gone | Date | Thu, 27 Jul 2017 09:26:59 +0300 |
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In the non-cooperative userfaultfd case, the process exit may race with outstanding mcopy_atomic called by the uffd monitor. Returning -ENOSPC instead of -EINVAL when mm is already gone will allow uffd monitor to distinguish this case from other error conditions.
Cc: stable@vger.kernel.org Fixes: 96333187ab162 ("userfaultfd_copy: return -ENOSPC in case mm has gone")
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> ---
Unfortunately, I've overlooked userfaultfd_zeropage when I updated userfaultd_copy :(
fs/userfaultfd.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index cadcd12a3d35..2d8c2d848668 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1643,6 +1643,8 @@ static int userfaultfd_zeropage(struct userfaultfd_ctx *ctx, ret = mfill_zeropage(ctx->mm, uffdio_zeropage.range.start, uffdio_zeropage.range.len); mmput(ctx->mm); + } else { + return -ENOSPC; } if (unlikely(put_user(ret, &user_uffdio_zeropage->zeropage))) return -EFAULT; -- 2.7.4
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