This is a note to let you know that I've just added the patch titled Bluetooth: Fix null pointer dereference in amp_read_loc_assoc_final_data to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bluetooth-fix-null-pointer-dereference-in-amp_read_l.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit de1671c971e6588ea760d5310fd02903b75b7e91 Author: Gopal Tiwari <gtiwari@xxxxxxxxxx> Date: Tue Feb 2 15:12:30 2021 +0530 Bluetooth: Fix null pointer dereference in amp_read_loc_assoc_final_data [ 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@xxxxxxxxxx> Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/bluetooth/amp.c b/net/bluetooth/amp.c index e32f34189007..b01b43ab6f83 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 = 0; + 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);