[PATCH 5.10] Bluetooth: btmtksdio: fix use-after-free at btmtksdio_recv_event

[PATCH 5.10] Bluetooth: btmtksdio: fix use-after-free at btmtksdio_recv_event

[Anastasia Belova]

From: Sean Wang <sean.wang@mediatek.com>

[ Upstream commit 0fab6361c4ba17d1b43a991bef4238a3c1754d35 ]

We should not access skb buffer data anymore after hci_recv_frame was
called.

[   39.634809] BUG: KASAN: use-after-free in btmtksdio_recv_event+0x1b0
[   39.634855] Read of size 1 at addr ffffff80cf28a60d by task kworker
[   39.634962] Call trace:
[   39.634974]  dump_backtrace+0x0/0x3b8
[   39.634999]  show_stack+0x20/0x2c
[   39.635016]  dump_stack_lvl+0x60/0x78
[   39.635040]  print_address_description+0x70/0x2f0
[   39.635062]  kasan_report+0x154/0x194
[   39.635079]  __asan_report_load1_noabort+0x44/0x50
[   39.635099]  btmtksdio_recv_event+0x1b0/0x1c4
[   39.635129]  btmtksdio_txrx_work+0x6cc/0xac4
[   39.635157]  process_one_work+0x560/0xc5c
[   39.635177]  worker_thread+0x7ec/0xcc0
[   39.635195]  kthread+0x2d0/0x3d0
[   39.635215]  ret_from_fork+0x10/0x20
[   39.635247] Allocated by task 0:
[   39.635260] (stack is not available)
[   39.635281] Freed by task 2392:
[   39.635295]  kasan_save_stack+0x38/0x68
[   39.635319]  kasan_set_track+0x28/0x3c
[   39.635338]  kasan_set_free_info+0x28/0x4c
[   39.635357]  ____kasan_slab_free+0x104/0x150
[   39.635374]  __kasan_slab_free+0x18/0x28
[   39.635391]  slab_free_freelist_hook+0x114/0x248
[   39.635410]  kfree+0xf8/0x2b4
[   39.635427]  skb_free_head+0x58/0x98
[   39.635447]  skb_release_data+0x2f4/0x410
[   39.635464]  skb_release_all+0x50/0x60
[   39.635481]  kfree_skb+0xc8/0x25c
[   39.635498]  hci_event_packet+0x894/0xca4 [bluetooth]
[   39.635721]  hci_rx_work+0x1c8/0x68c [bluetooth]
[   39.635925]  process_one_work+0x560/0xc5c
[   39.635951]  worker_thread+0x7ec/0xcc0
[   39.635970]  kthread+0x2d0/0x3d0
[   39.635990]  ret_from_fork+0x10/0x20
[   39.636021] The buggy address belongs to the object at ffffff80cf28a600
                which belongs to the cache kmalloc-512 of size 512
[   39.636039] The buggy address is located 13 bytes inside of
                512-byte region [ffffff80cf28a600, ffffff80cf28a800)

Fixes: 9aebfd4a2200 ("Bluetooth: mediatek: add support for MediaTek MT7663S and MT7668S SDIO devices")
Co-developed-by: Yake Yang <yake.yang@mediatek.com>
Signed-off-by: Yake Yang <yake.yang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Anastasia Belova <abelova@astralinux.ru>
---
Backport fix for CVE-2022-49470
 drivers/bluetooth/btmtksdio.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/btmtksdio.c b/drivers/bluetooth/btmtksdio.c
index c41560be39fb..6b31ee1a1dd9 100644
--- a/drivers/bluetooth/btmtksdio.c
+++ b/drivers/bluetooth/btmtksdio.c
@@ -331,6 +331,7 @@ static int btmtksdio_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	struct btmtksdio_dev *bdev = hci_get_drvdata(hdev);
 	struct hci_event_hdr *hdr = (void *)skb->data;
+	u8 evt = hdr->evt;
 	int err;
 
 	/* Fix up the vendor event id with 0xff for vendor specific instead
@@ -355,7 +356,7 @@ static int btmtksdio_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
 	if (err < 0)
 		goto err_free_skb;
 
-	if (hdr->evt == HCI_EV_VENDOR) {
+	if (evt == HCI_EV_VENDOR) {
 		if (test_and_clear_bit(BTMTKSDIO_TX_WAIT_VND_EVT,
 				       &bdev->tx_state)) {
 			/* Barrier to sync with other CPUs */
-- 
2.43.0

RE: [5.10] Bluetooth: btmtksdio: fix use-after-free at btmtksdio_recv_event

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 560 bytes --]

This is an automated email and please do not reply to this email.

Dear Submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
While preparing the CI tests, the patches you submitted couldn't be applied to the current HEAD of the repository.

----- Output -----

error: patch failed: drivers/bluetooth/btmtksdio.c:331
error: drivers/bluetooth/btmtksdio.c: patch does not apply
hint: Use 'git am --show-current-patch' to see the failed patch

Please resolve the issue and submit the patches again.


---
Regards,
Linux Bluetooth