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: 4816c94064 ("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>
This commit is contained in:
Stephan Mueller 2017-08-10 08:06:18 +02:00 committed by Herbert Xu
parent 8861249c74
commit dea3eb8b45

View File

@ -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)