[PATCH] wifi: mwifiex: bound SDIO fw dump count by memory table size

["Tianchu Chen" <tianchu.chen@linux.dev>]

From: Tianchu Chen <flynnnchen@tencent.com>

mwifiex_sdio_fw_dump() reads the number of memory regions (dump_num) from 
a device register and uses it to index the static 15-entry
mem_type_mapping_tbl[] without any bounds check. A bogus device can
report a dump_num larger than the table, making each loop iteration
store a vmalloc pointer and a device-controlled size past the end
of the table into adjacent .data (up to ~5.7KB when dump_num is 255).

The dump path runs after command timeouts or firmware crashes, so a
bogus device can first force an error to trigger the dump and
then report a bogus dump_num.

Aborting the dump only loses the firmware snapshot; the card reset 
that follows is unaffected, so error recovery still completes.

Discovered by Atuin - Automated Vulnerability Discovery Engine.

Fixes: 54881c6b37c8d ("mwifiex: add firmware dump feature for SDIO")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Tianchu Chen <flynnnchen@tencent.com>
---
 drivers/net/wireless/marvell/mwifiex/sdio.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/wireless/marvell/mwifiex/sdio.c b/drivers/net/wireless/marvell/mwifiex/sdio.c
index f039d6f19183a..e40ca40418b30 100644
--- a/drivers/net/wireless/marvell/mwifiex/sdio.c
+++ b/drivers/net/wireless/marvell/mwifiex/sdio.c
@@ -2795,6 +2795,11 @@ static void mwifiex_sdio_fw_dump(struct mwifiex_adapter *adapter)
 		mwifiex_dbg(adapter, ERROR, "SDIO read memory length err\n");
 		goto done;
 	}
+	if (dump_num > ARRAY_SIZE(mem_type_mapping_tbl)) {
+		mwifiex_dbg(adapter, ERROR,
+			    "Invalid fw dump num: %d\n", dump_num);
+		goto done;
+	}
 
 	/* Read the length of every memory which will dump */
 	for (idx = 0; idx < dump_num; idx++) {
-- 
2.51.0