Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 14/18] lib/mpi: kunmap after finishing accessing buffer | Date | Tue, 5 Sep 2017 09:11:22 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Stephan Mueller <smueller@chronox.de>
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 <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- lib/mpi/mpicoder.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -364,11 +364,11 @@ MPI mpi_read_raw_from_sgl(struct scatter } 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 scatter 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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