| From a1bfe78df1b64f61859a6aa82dbca0383d2c06df Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 27 Dec 2022 15:27:39 +0100 |
| Subject: lib/mpi: Fix buffer overrun when SG is too long |
| |
| 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 eead4b3394668..4f73db248009e 100644 |
| --- a/lib/mpi/mpicoder.c |
| +++ b/lib/mpi/mpicoder.c |
| @@ -397,7 +397,8 @@ 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; |
| -- |
| 2.39.2 |
| |
