[PATCH AUTOSEL 4.14 08/16] Bluetooth: Fix null pointer dereference in amp_read_loc_assoc_final_data

Sasha Levin
2021-02-24T14:17:52Z

From: Gopal Tiwari <gtiwari@redhat.com>

[ Upstream commit e8bd76ede155fd54d8c41d045dda43cd3174d506 ]

kernel panic trace looks like:

#5 [ffffb9e08698fc80] do_page_fault at ffffffffb666e0d7
#6 [ffffb9e08698fcb0] page_fault at ffffffffb70010fe
[exception RIP: amp_read_loc_assoc_final_data+63]
RIP: ffffffffc06ab54f RSP: ffffb9e08698fd68 RFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8c8845a5a000 RCX: 0000000000000004
RDX: 0000000000000000 RSI: ffff8c8b9153d000 RDI: ffff8c8845a5a000
RBP: ffffb9e08698fe40 R8: 00000000000330e0 R9: ffffffffc0675c94
R10: ffffb9e08698fe58 R11: 0000000000000001 R12: ffff8c8b9cbf6200
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8c8b2026da0b
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#7 [ffffb9e08698fda8] hci_event_packet at ffffffffc0676904 [bluetooth]
#8 [ffffb9e08698fe50] hci_rx_work at ffffffffc06629ac [bluetooth]
#9 [ffffb9e08698fe98] process_one_work at ffffffffb66f95e7

hcon->amp_mgr seems NULL triggered kernel panic in following line inside
function amp_read_loc_assoc_final_data

set_bit(READ_LOC_AMP_ASSOC_FINAL, &mgr->state);

Fixed by checking NULL for mgr.

Signed-off-by: Gopal Tiwari <gtiwari@redhat.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/bluetooth/amp.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/bluetooth/amp.c b/net/bluetooth/amp.c
index ebcab5bbadd7e..9f645a1d0202d 100644
--- a/net/bluetooth/amp.c
+++ b/net/bluetooth/amp.c
@@ -305,6 +305,9 @@ void amp_read_loc_assoc_final_data(struct hci_dev *hdev,
struct hci_request req;
int err;

+ if (!mgr)
+ return;
+
cp.phy_handle = hcon->handle;
cp.len_so_far = cpu_to_le16(0);
cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
--
2.27.0