[PATCH 4.19 121/338] ath9k_htc: fix uninit value bugs

Greg Kroah-Hartman
2022-04-14T13:32:47Z

From: Pavel Skripkin <paskripkin@gmail.com>

[ Upstream commit d1e0df1c57bd30871dd1c855742a7c346dbca853 ]

Syzbot reported 2 KMSAN bugs in ath9k. All of them are caused by missing
field initialization.

In htc_connect_service() svc_meta_len and pad are not initialized. Based
on code it looks like in current skb there is no service data, so simply
initialize svc_meta_len to 0.

htc_issue_send() does not initialize htc_frame_hdr::control array. Based
on firmware code, it will initialize it by itself, so simply zero whole
array to make KMSAN happy

Fail logs:

BUG: KMSAN: kernel-usb-infoleak in usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
hif_usb_send_regout drivers/net/wireless/ath/ath9k/hif_usb.c:127 [inline]
hif_usb_send+0x5f0/0x16f0 drivers/net/wireless/ath/ath9k/hif_usb.c:479
htc_issue_send drivers/net/wireless/ath/ath9k/htc_hst.c:34 [inline]
htc_connect_service+0x143e/0x1960 drivers/net/wireless/ath/ath9k/htc_hst.c:275
...

Uninit was created at:
slab_post_alloc_hook mm/slab.h:524 [inline]
slab_alloc_node mm/slub.c:3251 [inline]
__kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4974
kmalloc_reserve net/core/skbuff.c:354 [inline]
__alloc_skb+0x545/0xf90 net/core/skbuff.c:426
alloc_skb include/linux/skbuff.h:1126 [inline]
htc_connect_service+0x1029/0x1960 drivers/net/wireless/ath/ath9k/htc_hst.c:258
...

Bytes 4-7 of 18 are uninitialized
Memory access of size 18 starts at ffff888027377e00

BUG: KMSAN: kernel-usb-infoleak in usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
hif_usb_send_regout drivers/net/wireless/ath/ath9k/hif_usb.c:127 [inline]
hif_usb_send+0x5f0/0x16f0 drivers/net/wireless/ath/ath9k/hif_usb.c:479
htc_issue_send drivers/net/wireless/ath/ath9k/htc_hst.c:34 [inline]
htc_connect_service+0x143e/0x1960 drivers/net/wireless/ath/ath9k/htc_hst.c:275
...

Uninit was created at:
slab_post_alloc_hook mm/slab.h:524 [inline]
slab_alloc_node mm/slub.c:3251 [inline]
__kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4974
kmalloc_reserve net/core/skbuff.c:354 [inline]
__alloc_skb+0x545/0xf90 net/core/skbuff.c:426
alloc_skb include/linux/skbuff.h:1126 [inline]
htc_connect_service+0x1029/0x1960 drivers/net/wireless/ath/ath9k/htc_hst.c:258
...

Bytes 16-17 of 18 are uninitialized
Memory access of size 18 starts at ffff888027377e00

Fixes: fb9987d0f748 ("ath9k_htc: Support for AR9271 chipset.")
Reported-by: syzbot+f83a1df1ed4f67e8d8ad@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220115122733.11160-1-paskripkin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/ath/ath9k/htc_hst.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/net/wireless/ath/ath9k/htc_hst.c b/drivers/net/wireless/ath/ath9k/htc_hst.c
index 05fca38b38ed..e37de14bc502 100644
--- a/drivers/net/wireless/ath/ath9k/htc_hst.c
+++ b/drivers/net/wireless/ath/ath9k/htc_hst.c
@@ -30,6 +30,7 @@ static int htc_issue_send(struct htc_target *target, struct sk_buff* skb,
hdr->endpoint_id = epid;
hdr->flags = flags;
hdr->payload_len = cpu_to_be16(len);
+ memset(hdr->control, 0, sizeof(hdr->control));

status = target->hif->send(target->hif_dev, endpoint->ul_pipeid, skb);

@@ -274,6 +275,10 @@ int htc_connect_service(struct htc_target *target,
conn_msg->dl_pipeid = endpoint->dl_pipeid;
conn_msg->ul_pipeid = endpoint->ul_pipeid;

+ /* To prevent infoleak */
+ conn_msg->svc_meta_len = 0;
+ conn_msg->pad = 0;
+
ret = htc_issue_send(target, skb, skb->len, 0, ENDPOINT0);
if (ret)
goto err;
--
2.34.1