Subject: [PATCH AUTOSEL 4.19 005/158] ath10k: add peer id check in ath10k_peer_find_by_id

From: Sasha Levin <[email-masked]>
Date: Mon, 15 Jul 2019 10:15:36 -0400

From: Wen Gong <[email-masked]>

[ Upstream commit 49ed34b835e231aa941257394716bc689bc98d9f ]

For some SDIO chip, the peer id is 65535 for MPDU with error status,
then test_bit will trigger buffer overflow for peer's memory, if kasan
enabled, it will report error.

Reason is when station is in disconnecting status, firmware do not delete
the peer info since it not disconnected completely, meanwhile some AP will
still send data packet to station, then hardware will receive the packet
and send to firmware, firmware's logic will report peer id of 65535 for
MPDU with error status.

Add check for overflow the size of peer's peer_ids will avoid the buffer
overflow access.

Call trace of kasan:
dump_backtrace+0x0/0x2ec
show_stack+0x20/0x2c
__dump_stack+0x20/0x28
dump_stack+0xc8/0xec
print_address_description+0x74/0x240
kasan_report+0x250/0x26c
__asan_report_load8_noabort+0x20/0x2c
ath10k_peer_find_by_id+0x180/0x1e4 [ath10k_core]
ath10k_htt_t2h_msg_handler+0x100c/0x2fd4 [ath10k_core]
ath10k_htt_htc_t2h_msg_handler+0x20/0x34 [ath10k_core]
ath10k_sdio_irq_handler+0xcc8/0x1678 [ath10k_sdio]
process_sdio_pending_irqs+0xec/0x370
sdio_run_irqs+0x68/0xe4
sdio_irq_work+0x1c/0x28
process_one_work+0x3d8/0x8b0
worker_thread+0x508/0x7cc
kthread+0x24c/0x264
ret_from_fork+0x10/0x18

Tested with QCA6174 SDIO with firmware
WLAN.RMH.4.4.1-00007-QCARMSWP-1.

Signed-off-by: Wen Gong <[email-masked]>
Signed-off-by: Kalle Valo <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/wireless/ath/ath10k/txrx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/ath/ath10k/txrx.c b/drivers/net/wireless/ath/ath10k/txrx.c
index cda164f6e9f6..6f62ddc0494c 100644
--- a/drivers/net/wireless/ath/ath10k/txrx.c
+++ b/drivers/net/wireless/ath/ath10k/txrx.c
@@ -156,6 +156,9 @@ struct ath10k_peer *ath10k_peer_find_by_id(struct ath10k *ar, int peer_id)
 {
 	struct ath10k_peer *peer;
 
+	if (peer_id >= BITS_PER_TYPE(peer->peer_ids))
+		return NULL;
+
 	lockdep_assert_held(&ar->data_lock);
 
 	list_for_each_entry(peer, &ar->peers, list)
-- 
2.20.1