Commit dea3eb8b authored Aug 10, 2017 by Stephan Mueller Committed by Herbert Xu Aug 22, 2017

lib/mpi: kunmap after finishing accessing buffer



Using sg_miter_start and sg_miter_next, the buffer of an SG is kmap'ed
to *buff. The current code calls sg_miter_stop (and thus kunmap) on the
SG entry before the last access of *buff.

The patch moves the sg_miter_stop call after the last access to *buff to
ensure that the memory pointed to by *buff is still mapped.

Fixes: 4816c940 ("lib/mpi: Fix SG miter leak")
Cc: <stable@vger.kernel.org>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

parent 8861249c

lib/mpi/mpicoder.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -364,11 +364,11 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
		}

		miter.consumed = lzeros;
		sg_miter_stop(&miter);

		nbytes -= lzeros;
		nbits = nbytes * 8;
		if (nbits > MAX_EXTERN_MPI_BITS) {
		sg_miter_stop(&miter);
		pr_info("MPI: mpi too large (%u bits)\n", nbits);
		return NULL;
		}
		@@ -376,6 +376,8 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
		if (nbytes > 0)
		nbits -= count_leading_zeros(*buff) - (BITS_PER_LONG - 8);

		sg_miter_stop(&miter);

		nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB);
		val = mpi_alloc(nlimbs);
		if (!val)

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