From: Archie Pusaka <apusaka@xxxxxxxxxxxx>
When in the middle of adding accept list, the userspace can still
remove devices, therefore causing crash if the removed device is
the one being processed.
Use a safe loop mechanism to guard against deletion while iterating
the pending items.
Below is a sample btsnoop log when user enters wrong passkey when
pairing a LE keyboard and the corresponding stacktrace.
@ MGMT Event: Command Complete (0x0001) plen 10
Add Device (0x0033) plen 7
Status: Success (0x00)
LE Address: CA:CA:BD:78:37:F9 (Static)
< HCI Command: LE Add Device To Accept List (0x08|0x0011) plen 7
Address type: Random (0x01)
Address: CA:CA:BD:78:37:F9 (Static)
@ MGMT Event: Device Removed (0x001b) plen 7
LE Address: CA:CA:BD:78:37:F9 (Static)
> HCI Event: Command Complete (0x0e) plen 4
LE Add Device To Accept List (0x08|0x0011) ncmd 1
Status: Success (0x00)
[ 167.409813] Call trace:
[ 167.409983] hci_le_add_accept_list_sync+0x64/0x26c
[ 167.410150] hci_update_passive_scan_sync+0x5f0/0x6dc
[ 167.410318] add_device_sync+0x18/0x24
[ 167.410486] hci_cmd_sync_work+0xe8/0x150
[ 167.410509] process_one_work+0x140/0x4d0
[ 167.410526] worker_thread+0x134/0x2e4
[ 167.410544] kthread+0x148/0x160
[ 167.410562] ret_from_fork+0x10/0x30
Signed-off-by: Archie Pusaka <apusaka@xxxxxxxxxxxx>
Reviewed-by: Zhengping Jiang <jiangzp@xxxxxxxxxx>
Reviewed-by: Michael Sun <michaelfsun@xxxxxxxxxx>
---
net/bluetooth/hci_sync.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 3067d94e7a8e..8e843d34f7de 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -1863,7 +1863,7 @@ struct sk_buff *hci_read_local_oob_data_sync(struct hci_dev *hdev,
*/
static u8 hci_update_accept_list_sync(struct hci_dev *hdev)
{
- struct hci_conn_params *params;
+ struct hci_conn_params *params, *tmp;
struct bdaddr_list *b, *t;
u8 num_entries = 0;
bool pend_conn, pend_report;
@@ -1930,7 +1930,7 @@ static u8 hci_update_accept_list_sync(struct hci_dev *hdev)
* just abort and return filer policy value to not use the
* accept list.
*/
- list_for_each_entry(params, &hdev->pend_le_conns, action) {
+ list_for_each_entry_safe(params, tmp, &hdev->pend_le_conns, action) {
err = hci_le_add_accept_list_sync(hdev, params, &num_entries);
if (err)
goto done;
@@ -1940,7 +1940,7 @@ static u8 hci_update_accept_list_sync(struct hci_dev *hdev)
* the list of pending reports and also add these to the
* accept list if there is still space. Abort if space runs out.
*/
- list_for_each_entry(params, &hdev->pend_le_reports, action) {
+ list_for_each_entry_safe(params, tmp, &hdev->pend_le_reports, action) {
err = hci_le_add_accept_list_sync(hdev, params, &num_entries);
if (err)
goto done;
--
2.37.1.359.gd136c6c3e2-goog
