Hi Archie, > hci_chan can be created in 2 places: hci_loglink_complete_evt() if > it is an AMP hci_chan, or l2cap_conn_add() otherwise. In theory, > Only AMP hci_chan should be removed by a call to > hci_disconn_loglink_complete_evt(). However, the controller might mess > up, call that function, and destroy an hci_chan which is not initiated > by hci_loglink_complete_evt(). > > This patch adds a verification that the destroyed hci_chan must have > been init'd by hci_loglink_complete_evt(). > > Example crash call trace: > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0xe3/0x144 lib/dump_stack.c:118 > print_address_description+0x67/0x22a mm/kasan/report.c:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report mm/kasan/report.c:412 [inline] > kasan_report+0x251/0x28f mm/kasan/report.c:396 > hci_send_acl+0x3b/0x56e net/bluetooth/hci_core.c:4072 > l2cap_send_cmd+0x5af/0x5c2 net/bluetooth/l2cap_core.c:877 > l2cap_send_move_chan_cfm_icid+0x8e/0xb1 net/bluetooth/l2cap_core.c:4661 > l2cap_move_fail net/bluetooth/l2cap_core.c:5146 [inline] > l2cap_move_channel_rsp net/bluetooth/l2cap_core.c:5185 [inline] > l2cap_bredr_sig_cmd net/bluetooth/l2cap_core.c:5464 [inline] > l2cap_sig_channel net/bluetooth/l2cap_core.c:5799 [inline] > l2cap_recv_frame+0x1d12/0x51aa net/bluetooth/l2cap_core.c:7023 > l2cap_recv_acldata+0x2ea/0x693 net/bluetooth/l2cap_core.c:7596 > hci_acldata_packet net/bluetooth/hci_core.c:4606 [inline] > hci_rx_work+0x2bd/0x45e net/bluetooth/hci_core.c:4796 > process_one_work+0x6f8/0xb50 kernel/workqueue.c:2175 > worker_thread+0x4fc/0x670 kernel/workqueue.c:2321 > kthread+0x2f0/0x304 kernel/kthread.c:253 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 > > Allocated by task 38: > set_track mm/kasan/kasan.c:460 [inline] > kasan_kmalloc+0x8d/0x9a mm/kasan/kasan.c:553 > kmem_cache_alloc_trace+0x102/0x129 mm/slub.c:2787 > kmalloc include/linux/slab.h:515 [inline] > kzalloc include/linux/slab.h:709 [inline] > hci_chan_create+0x86/0x26d net/bluetooth/hci_conn.c:1674 > l2cap_conn_add.part.0+0x1c/0x814 net/bluetooth/l2cap_core.c:7062 > l2cap_conn_add net/bluetooth/l2cap_core.c:7059 [inline] > l2cap_connect_cfm+0x134/0x852 net/bluetooth/l2cap_core.c:7381 > hci_connect_cfm+0x9d/0x122 include/net/bluetooth/hci_core.h:1404 > hci_remote_ext_features_evt net/bluetooth/hci_event.c:4161 [inline] > hci_event_packet+0x463f/0x72fa net/bluetooth/hci_event.c:5981 > hci_rx_work+0x197/0x45e net/bluetooth/hci_core.c:4791 > process_one_work+0x6f8/0xb50 kernel/workqueue.c:2175 > worker_thread+0x4fc/0x670 kernel/workqueue.c:2321 > kthread+0x2f0/0x304 kernel/kthread.c:253 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 > > Freed by task 1732: > set_track mm/kasan/kasan.c:460 [inline] > __kasan_slab_free mm/kasan/kasan.c:521 [inline] > __kasan_slab_free+0x106/0x128 mm/kasan/kasan.c:493 > slab_free_hook mm/slub.c:1409 [inline] > slab_free_freelist_hook+0xaa/0xf6 mm/slub.c:1436 > slab_free mm/slub.c:3009 [inline] > kfree+0x182/0x21e mm/slub.c:3972 > hci_disconn_loglink_complete_evt net/bluetooth/hci_event.c:4891 [inline] > hci_event_packet+0x6a1c/0x72fa net/bluetooth/hci_event.c:6050 > hci_rx_work+0x197/0x45e net/bluetooth/hci_core.c:4791 > process_one_work+0x6f8/0xb50 kernel/workqueue.c:2175 > worker_thread+0x4fc/0x670 kernel/workqueue.c:2321 > kthread+0x2f0/0x304 kernel/kthread.c:253 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 > > The buggy address belongs to the object at ffff8881d7af9180 > which belongs to the cache kmalloc-128 of size 128 > The buggy address is located 24 bytes inside of > 128-byte region [ffff8881d7af9180, ffff8881d7af9200) > The buggy address belongs to the page: > page:ffffea00075ebe40 count:1 mapcount:0 mapping:ffff8881da403200 index:0x0 > flags: 0x8000000000000200(slab) > raw: 8000000000000200 dead000000000100 dead000000000200 ffff8881da403200 > raw: 0000000000000000 0000000080150015 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8881d7af9080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb > ffff8881d7af9100: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >> ffff8881d7af9180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff8881d7af9200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8881d7af9280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > Signed-off-by: Archie Pusaka <apusaka@xxxxxxxxxxxx> > Reported-by: syzbot+98228e7407314d2d4ba2@xxxxxxxxxxxxxxxxxxxxxxxxx > Reviewed-by: Alain Michaud <alainm@xxxxxxxxxxxx> > Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx> > --- > > include/net/bluetooth/hci_core.h | 1 + > net/bluetooth/hci_event.c | 3 ++- > 2 files changed, 3 insertions(+), 1 deletion(-) patch has been applied to bluetooth-next tree. Regards Marcel
