In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_after() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct. Additionally split up a later
field-spanning memset() so that memset() can reason about the size.

Signed-off-by: Kees Cook <keesc...@chromium.org>
---
 drivers/net/wireless/ath/ath11k/hal_rx.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/hal_rx.c 
b/drivers/net/wireless/ath/ath11k/hal_rx.c
index 325055ca41ab..c72b6b45b3ba 100644
--- a/drivers/net/wireless/ath/ath11k/hal_rx.c
+++ b/drivers/net/wireless/ath/ath11k/hal_rx.c
@@ -29,8 +29,7 @@ static int ath11k_hal_reo_cmd_queue_stats(struct hal_tlv_hdr 
*tlv,
                  FIELD_PREP(HAL_TLV_HDR_LEN, sizeof(*desc));
 
        desc = (struct hal_reo_get_queue_stats *)tlv->value;
-       memset(&desc->queue_addr_lo, 0,
-              (sizeof(*desc) - sizeof(struct hal_reo_cmd_hdr)));
+       memset_after(desc, 0, cmd);
 
        desc->cmd.info0 &= ~HAL_REO_CMD_HDR_INFO0_STATUS_REQUIRED;
        if (cmd->flag & HAL_REO_CMD_FLG_NEED_STATUS)
@@ -62,8 +61,7 @@ static int ath11k_hal_reo_cmd_flush_cache(struct ath11k_hal 
*hal, struct hal_tlv
                  FIELD_PREP(HAL_TLV_HDR_LEN, sizeof(*desc));
 
        desc = (struct hal_reo_flush_cache *)tlv->value;
-       memset(&desc->cache_addr_lo, 0,
-              (sizeof(*desc) - sizeof(struct hal_reo_cmd_hdr)));
+       memset_after(desc, 0, cmd);
 
        desc->cmd.info0 &= ~HAL_REO_CMD_HDR_INFO0_STATUS_REQUIRED;
        if (cmd->flag & HAL_REO_CMD_FLG_NEED_STATUS)
@@ -101,8 +99,7 @@ static int ath11k_hal_reo_cmd_update_rx_queue(struct 
hal_tlv_hdr *tlv,
                  FIELD_PREP(HAL_TLV_HDR_LEN, sizeof(*desc));
 
        desc = (struct hal_reo_update_rx_queue *)tlv->value;
-       memset(&desc->queue_addr_lo, 0,
-              (sizeof(*desc) - sizeof(struct hal_reo_cmd_hdr)));
+       memset_after(desc, 0, cmd);
 
        desc->cmd.info0 &= ~HAL_REO_CMD_HDR_INFO0_STATUS_REQUIRED;
        if (cmd->flag & HAL_REO_CMD_FLG_NEED_STATUS)
@@ -762,15 +759,17 @@ void ath11k_hal_reo_qdesc_setup(void *vaddr, int tid, u32 
ba_window_size,
         * size changes and also send WMI message to FW to change the REO
         * queue descriptor in Rx peer entry as part of dp_rx_tid_update.
         */
-       memset(ext_desc, 0, 3 * sizeof(*ext_desc));
+       memset(ext_desc, 0, sizeof(*ext_desc));
        ath11k_hal_reo_set_desc_hdr(&ext_desc->desc_hdr, HAL_DESC_REO_OWNED,
                                    HAL_DESC_REO_QUEUE_EXT_DESC,
                                    REO_QUEUE_DESC_MAGIC_DEBUG_PATTERN_1);
        ext_desc++;
+       memset(ext_desc, 0, sizeof(*ext_desc));
        ath11k_hal_reo_set_desc_hdr(&ext_desc->desc_hdr, HAL_DESC_REO_OWNED,
                                    HAL_DESC_REO_QUEUE_EXT_DESC,
                                    REO_QUEUE_DESC_MAGIC_DEBUG_PATTERN_2);
        ext_desc++;
+       memset(ext_desc, 0, sizeof(*ext_desc));
        ath11k_hal_reo_set_desc_hdr(&ext_desc->desc_hdr, HAL_DESC_REO_OWNED,
                                    HAL_DESC_REO_QUEUE_EXT_DESC,
                                    REO_QUEUE_DESC_MAGIC_DEBUG_PATTERN_3);
-- 
2.30.2

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