From: Herbert Xu herbert@gondor.apana.org.au
[ Upstream commit 7361d1bc307b926cbca214ab67b641123c2d6357 ]
The helper mpi_read_raw_from_sgl sets the number of entries in the SG list according to nbytes. However, if the last entry in the SG list contains more data than nbytes, then it may overrun the buffer because it only allocates enough memory for nbytes.
Fixes: 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") Reported-by: Roberto Sassu roberto.sassu@huaweicloud.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Reviewed-by: Eric Biggers ebiggers@google.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- lib/mpi/mpicoder.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index 39c4c67310946..3cb6bd148fa9e 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -504,7 +504,8 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
while (sg_miter_next(&miter)) { buff = miter.addr; - len = miter.length; + len = min_t(unsigned, miter.length, nbytes); + nbytes -= len;
for (x = 0; x < len; x++) { a <<= 8;