diff options
Diffstat (limited to 'lib/mpi')
| -rw-r--r-- | lib/mpi/mpicoder.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index 3db76b8c1115..ec533a6c77b5 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -135,7 +135,9 @@ EXPORT_SYMBOL_GPL(mpi_read_from_buffer); * @buf: bufer to which the output will be written to. Needs to be at * leaset mpi_get_size(a) long. * @buf_len: size of the buf. - * @nbytes: receives the actual length of the data written. + * @nbytes: receives the actual length of the data written on success and + * the data to-be-written on -EOVERFLOW in case buf_len was too + * small. * @sign: if not NULL, it will be set to the sign of a. * * Return: 0 on success or error code in case of error @@ -148,7 +150,7 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, unsigned int n = mpi_get_size(a); int i, lzeros = 0; - if (buf_len < n || !buf || !nbytes) + if (!buf || !nbytes) return -EINVAL; if (sign) @@ -163,6 +165,11 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, break; } + if (buf_len < n - lzeros) { + *nbytes = n - lzeros; + return -EOVERFLOW; + } + p = buf; *nbytes = n - lzeros; @@ -332,7 +339,8 @@ EXPORT_SYMBOL_GPL(mpi_set_buffer); * @nbytes: in/out param - it has the be set to the maximum number of * bytes that can be written to sgl. This has to be at least * the size of the integer a. On return it receives the actual - * length of the data written. + * length of the data written on success or the data that would + * be written if buffer was too small. * @sign: if not NULL, it will be set to the sign of a. * * Return: 0 on success or error code in case of error @@ -345,7 +353,7 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes, unsigned int n = mpi_get_size(a); int i, x, y = 0, lzeros = 0, buf_len; - if (!nbytes || *nbytes < n) + if (!nbytes) return -EINVAL; if (sign) @@ -360,6 +368,11 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes, break; } + if (*nbytes < n - lzeros) { + *nbytes = n - lzeros; + return -EOVERFLOW; + } + *nbytes = n - lzeros; buf_len = sgl->length; p2 = sg_virt(sgl); |