[PATCH v3] wifi: wilc1000: use vmm_table as array in wilc struct

Alexis Lothoré
2023-10-17T08:42:43Z

From: Ajay Singh <ajay.kathat@microchip.com>

Enabling KASAN and running some iperf tests raises some memory issues with
vmm_table:

BUG: KASAN: slab-out-of-bounds in wilc_wlan_handle_txq+0x6ac/0xdb4
Write of size 4 at addr c3a61540 by task wlan0-tx/95

KASAN detects that we are writing data beyond range allocated to vmm_table.
There is indeed a mismatch between the size passed to allocator in
wilc_wlan_init, and the range of possible indexes used later: allocation
size is missing a multiplication by sizeof(u32)

Fixes: 40b717bfcefa ("wifi: wilc1000: fix DMA on stack objects")
Cc: stable@vger.kernel.org
Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
---
Changes in v3:
- Use kcalloc instead of kzalloc
- Link to v2: https://lore.kernel.org/r/20231016-wilc1000_tx_oops-v2-1-8d1982a29ef1@bootlin.com

Changes in v2:
- keep dedicated dynamic allocation for vmm_table
- Link to v1: https://lore.kernel.org/r/20231013-wilc1000_tx_oops-v1-1-3761beb9524d@bootlin.com
---
drivers/net/wireless/microchip/wilc1000/wlan.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/microchip/wilc1000/wlan.c b/drivers/net/wireless/microchip/wilc1000/wlan.c
index 58bbf50081e4..9eb115c79c90 100644
--- a/drivers/net/wireless/microchip/wilc1000/wlan.c
+++ b/drivers/net/wireless/microchip/wilc1000/wlan.c
@@ -1492,7 +1492,7 @@ int wilc_wlan_init(struct net_device *dev)
}

if (!wilc->vmm_table)
- wilc->vmm_table = kzalloc(WILC_VMM_TBL_SIZE, GFP_KERNEL);
+ wilc->vmm_table = kcalloc(WILC_VMM_TBL_SIZE, sizeof(u32), GFP_KERNEL);

if (!wilc->vmm_table) {
ret = -ENOBUFS;

---
base-commit: ea12d85cbfd6b08fff40a4fefccc011b6cfadf8e
change-id: 20231012-wilc1000_tx_oops-58ce91ee3e93

Best regards,
--
Alexis Lothoré, Bootlin
Embedded Linux and Kernel engineering