From 31decdcd83695b6a0e84794ecc470c454b4088f7 Mon Sep 17 00:00:00 2001 From: Stephan Mueller Date: Thu, 10 Aug 2017 08:06:18 +0200 Subject: [PATCH] lib/mpi: kunmap after finishing accessing buffer commit dea3eb8b452e36cf2dd572b0a797915ccf452ae6 upstream. 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: 4816c9406430 ("lib/mpi: Fix SG miter leak") Signed-off-by: Stephan Mueller Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- lib/mpi/mpicoder.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index 5a0f75a..eead4b3 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -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) -- 2.7.4