accel/qaic: Fix possible data corruption in BOs > 2G

When slicing a BO, we need to iterate through the BO's sgt to find the
right pieces to construct the slice. Some of the data types chosen for
this process are incorrectly too small, and can overflow. This can
result in the incorrect slice construction, which can lead to data
corruption in workload execution.

The device can only handle 32-bit sized transfers, and the scatterlist
struct only supports 32-bit buffer sizes, so our upper limit for an
individual transfer is an unsigned int. Using an int is incorrect due to
the reservation of the sign bit. Upgrade the length of a scatterlist
entry and the offsets into a scatterlist entry to unsigned int for a
correct representation.

While each transfer may be limited to 32-bits, the overall BO may exceed
that size. For counting the total length of the BO, we need a type that
can represent the largest allocation possible on the system. That is the
definition of size_t, so use it.

Fixes: ff13be830333 ("accel/qaic: Add datapath")
Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
Reviewed-by: Lizhi Hou <lizhi.hou@amd.com>
Reviewed-by: Troy Hanson <quic_thanson@quicinc.com>
Reviewed-by: Youssef Samir <quic_yabdulra@quicinc.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250306171959.853466-1-jeff.hugo@oss.qualcomm.com

diff --git a/drivers/accel/qaic/qaic_data.c b/drivers/accel/qaic/qaic_data.c
index c20eb63750f517c07c88132bb79766cbbe010688..ffcdf5738d099989153e3c2705db4ceab358a8d0 100644 (file)
--- a/drivers/accel/qaic/qaic_data.c
+++ b/drivers/accel/qaic/qaic_data.c
@@ -172,9 +172,10 @@ static void free_slice(struct kref *kref)
 static int clone_range_of_sgt_for_slice(struct qaic_device *qdev, struct sg_table **sgt_out,
                                        struct sg_table *sgt_in, u64 size, u64 offset)
 {
-       int total_len, len, nents, offf = 0, offl = 0;
        struct scatterlist *sg, *sgn, *sgf, *sgl;
+       unsigned int len, nents, offf, offl;
        struct sg_table *sgt;
+       size_t total_len;
        int ret, j;
 
        /* find out number of relevant nents needed for this mem */
@@ -182,6 +183,8 @@ static int clone_range_of_sgt_for_slice(struct qaic_device *qdev, struct sg_tabl
        sgf = NULL;
        sgl = NULL;
        nents = 0;
+       offf = 0;
+       offl = 0;
 
        size = size ? size : PAGE_SIZE;
        for_each_sgtable_dma_sg(sgt_in, sg, j) {