From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
This fixes the following error caused by hci_conn being freed while
hcy_acl_create_conn_sync is pending:
==================================================================
BUG: KASAN: slab-use-after-free in hci_acl_create_conn_sync+0xa7/0x2e0
Write of size 2 at addr ffff888002ae0036 by task kworker/u3:0/848
CPU: 0 PID: 848 Comm: kworker/u3:0 Not tainted 6.8.0-rc6-g2ab3e8d67fc1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38
04/01/2014
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
<TASK>
dump_stack_lvl+0x21/0x70
print_report+0xce/0x620
? preempt_count_sub+0x13/0xc0
? __virt_addr_valid+0x15f/0x310
? hci_acl_create_conn_sync+0xa7/0x2e0
kasan_report+0xdf/0x110
? hci_acl_create_conn_sync+0xa7/0x2e0
hci_acl_create_conn_sync+0xa7/0x2e0
? __pfx_hci_acl_create_conn_sync+0x10/0x10
? __pfx_lock_release+0x10/0x10
? __pfx_hci_acl_create_conn_sync+0x10/0x10
hci_cmd_sync_work+0x138/0x1c0
process_one_work+0x405/0x800
? __pfx_lock_acquire+0x10/0x10
? __pfx_process_one_work+0x10/0x10
worker_thread+0x37b/0x670
? __pfx_worker_thread+0x10/0x10
kthread+0x19b/0x1e0
? kthread+0xfe/0x1e0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x2f/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 847:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0x8f/0xa0
hci_conn_add+0xc6/0x970
hci_connect_acl+0x309/0x410
pair_device+0x4fb/0x710
hci_sock_sendmsg+0x933/0xef0
sock_write_iter+0x2c3/0x2d0
do_iter_readv_writev+0x21a/0x2e0
vfs_writev+0x21c/0x7b0
do_writev+0x14a/0x180
do_syscall_64+0x77/0x150
entry_SYSCALL_64_after_hwframe+0x6c/0x74
Freed by task 847:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0xfa/0x150
kfree+0xcb/0x250
device_release+0x58/0xf0
kobject_put+0xbb/0x160
hci_conn_del+0x281/0x570
hci_conn_hash_flush+0xfc/0x130
hci_dev_close_sync+0x336/0x960
hci_dev_close+0x10e/0x140
hci_sock_ioctl+0x14a/0x5c0
sock_ioctl+0x58a/0x5d0
__x64_sys_ioctl+0x480/0xf60
do_syscall_64+0x77/0x150
entry_SYSCALL_64_after_hwframe+0x6c/0x74
Fixes: 45340097ce6e ("Bluetooth: hci_conn: Only do ACL connections sequentially")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
---
net/bluetooth/hci_sync.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 8a3d0d1f7871..f6b662369322 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -6709,6 +6709,9 @@ static int hci_acl_create_conn_sync(struct hci_dev *hdev, void *data)
struct hci_cp_create_conn cp;
int err;
+ if (!hci_conn_valid(hdev, conn))
+ return -ECANCELED;
+
/* Many controllers disallow HCI Create Connection while it is doing
* HCI Inquiry. So we cancel the Inquiry first before issuing HCI Create
* Connection. This may cause the MGMT discovering state to become false
--
2.43.0
