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: 4816c94 ("lib/mpi: Fix SG miter leak") Cc: <[email protected]> Signed-off-by: Stephan Mueller <[email protected]> Signed-off-by: Herbert Xu <[email protected]>
berg · Aug 22, 2017 · dea3eb8 · dea3eb8
1 parent 8861249
commit dea3eb8
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
@@ -364,18 +364,20 @@ 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;
 	}
 
 	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)