releases/6.1.16/wifi-mt76-mt7921s-fix-slab-out-of-bounds-access-in-s.patch

From d9ac096f6c6f112d91de01544c367448f34f2d3e Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Thu, 1 Dec 2022 23:53:37 +0800
Subject: wifi: mt76: mt7921s: fix slab-out-of-bounds access in sdio host

From: Deren Wu <deren.wu@mediatek.com>

[ Upstream commit aec4cf2ea0797e28f18f8dbe01943a56d987fe56 ]

SDIO may need addtional 511 bytes to align bus operation. If the tailroom
of this skb is not big enough, we would access invalid memory region.
For low level operation, increase skb size to keep valid memory access in
SDIO host.

Error message:
[69.951] BUG: KASAN: slab-out-of-bounds in sg_copy_buffer+0xe9/0x1a0
[69.951] Read of size 64 at addr ffff88811c9cf000 by task kworker/u16:7/451
[69.951] CPU: 4 PID: 451 Comm: kworker/u16:7 Tainted: G W  OE  6.1.0-rc5 #1
[69.951] Workqueue: kvub300c vub300_cmndwork_thread [vub300]
[69.951] Call Trace:
[69.951]  <TASK>
[69.952]  dump_stack_lvl+0x49/0x63
[69.952]  print_report+0x171/0x4a8
[69.952]  kasan_report+0xb4/0x130
[69.952]  kasan_check_range+0x149/0x1e0
[69.952]  memcpy+0x24/0x70
[69.952]  sg_copy_buffer+0xe9/0x1a0
[69.952]  sg_copy_to_buffer+0x12/0x20
[69.952]  __command_write_data.isra.0+0x23c/0xbf0 [vub300]
[69.952]  vub300_cmndwork_thread+0x17f3/0x58b0 [vub300]
[69.952]  process_one_work+0x7ee/0x1320
[69.952]  worker_thread+0x53c/0x1240
[69.952]  kthread+0x2b8/0x370
[69.952]  ret_from_fork+0x1f/0x30
[69.952]  </TASK>

[69.952] Allocated by task 854:
[69.952]  kasan_save_stack+0x26/0x50
[69.952]  kasan_set_track+0x25/0x30
[69.952]  kasan_save_alloc_info+0x1b/0x30
[69.952]  __kasan_kmalloc+0x87/0xa0
[69.952]  __kmalloc_node_track_caller+0x63/0x150
[69.952]  kmalloc_reserve+0x31/0xd0
[69.952]  __alloc_skb+0xfc/0x2b0
[69.952]  __mt76_mcu_msg_alloc+0xbf/0x230 [mt76]
[69.952]  mt76_mcu_send_and_get_msg+0xab/0x110 [mt76]
[69.952]  __mt76_mcu_send_firmware.cold+0x94/0x15d [mt76]
[69.952]  mt76_connac_mcu_send_ram_firmware+0x415/0x54d [mt76_connac_lib]
[69.952]  mt76_connac2_load_ram.cold+0x118/0x4bc [mt76_connac_lib]
[69.952]  mt7921_run_firmware.cold+0x2e9/0x405 [mt7921_common]
[69.952]  mt7921s_mcu_init+0x45/0x80 [mt7921s]
[69.953]  mt7921_init_work+0xe1/0x2a0 [mt7921_common]
[69.953]  process_one_work+0x7ee/0x1320
[69.953]  worker_thread+0x53c/0x1240
[69.953]  kthread+0x2b8/0x370
[69.953]  ret_from_fork+0x1f/0x30
[69.953] The buggy address belongs to the object at ffff88811c9ce800
             which belongs to the cache kmalloc-2k of size 2048
[69.953] The buggy address is located 0 bytes to the right of
             2048-byte region [ffff88811c9ce800, ffff88811c9cf000)

[69.953] Memory state around the buggy address:
[69.953]  ffff88811c9cef00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[69.953]  ffff88811c9cef80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[69.953] >ffff88811c9cf000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[69.953]                    ^
[69.953]  ffff88811c9cf080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[69.953]  ffff88811c9cf100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: 764dee47e2c1 ("mt76: sdio: move common code in mt76_sdio module")
Suggested-by: Lorenzo Bianconi <lorenzo@kernel.org>
Tested-by: YN Chen <YN.Chen@mediatek.com>
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/mediatek/mt76/sdio_txrx.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/sdio_txrx.c b/drivers/net/wireless/mediatek/mt76/sdio_txrx.c
index bfc4de50a4d23..ddd8c0cc744df 100644
--- a/drivers/net/wireless/mediatek/mt76/sdio_txrx.c
+++ b/drivers/net/wireless/mediatek/mt76/sdio_txrx.c
@@ -254,6 +254,10 @@ static int mt76s_tx_run_queue(struct mt76_dev *dev, struct mt76_queue *q)
 
 		if (!test_bit(MT76_STATE_MCU_RUNNING, &dev->phy.state)) {
 			__skb_put_zero(e->skb, 4);
+			err = __skb_grow(e->skb, roundup(e->skb->len,
+							 sdio->func->cur_blksize));
+			if (err)
+				return err;
 			err = __mt76s_xmit_queue(dev, e->skb->data,
 						 e->skb->len);
 			if (err)
-- 
2.39.2