Hello, syzbot found the following crash on: HEAD commit: 7cc2a8ea Merge tag 'block-5.8-2020-07-01' of git://git.ker.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=10261e7b100000 kernel config: https://syzkaller.appspot.com/x/.config?x=7be693511b29b338 dashboard link: https://syzkaller.appspot.com/bug?extid=d8489a79b781849b9c46 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12d62e6d100000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1061f66d100000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+d8489a79b781849b9c46@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:406 [inline] BUG: KASAN: slab-out-of-bounds in bacpy include/net/bluetooth/bluetooth.h:274 [inline] BUG: KASAN: slab-out-of-bounds in hci_extended_inquiry_result_evt.isra.0+0x1be/0x5e0 net/bluetooth/hci_event.c:4394 Read of size 6 at addr ffff88809f0ec404 by task kworker/u5:2/6794 CPU: 0 PID: 6794 Comm: kworker/u5:2 Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: hci0 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x13d/0x180 mm/kasan/generic.c:192 memcpy+0x20/0x60 mm/kasan/common.c:105 memcpy include/linux/string.h:406 [inline] bacpy include/net/bluetooth/bluetooth.h:274 [inline] hci_extended_inquiry_result_evt.isra.0+0x1be/0x5e0 net/bluetooth/hci_event.c:4394 hci_event_packet+0x2828/0x86f5 net/bluetooth/hci_event.c:6115 hci_rx_work+0x22e/0xb10 net/bluetooth/hci_core.c:4705 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Allocated by task 6797: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0xae/0x550 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1083 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:377 [inline] vhci_get_user drivers/bluetooth/hci_vhci.c:165 [inline] vhci_write+0xbd/0x450 drivers/bluetooth/hci_vhci.c:285 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write+0x422/0x650 fs/read_write.c:484 __vfs_write+0xc9/0x100 fs/read_write.c:497 vfs_write+0x268/0x5d0 fs/read_write.c:559 ksys_write+0x12d/0x250 fs/read_write.c:612 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 4786: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x103/0x2c0 mm/slab.c:3757 skb_free_head net/core/skbuff.c:590 [inline] skb_release_data+0x6d9/0x910 net/core/skbuff.c:610 skb_release_all net/core/skbuff.c:664 [inline] __kfree_skb+0x46/0x60 net/core/skbuff.c:678 sk_wmem_free_skb include/net/sock.h:1532 [inline] tcp_rtx_queue_unlink_and_free include/net/tcp.h:1849 [inline] tcp_clean_rtx_queue net/ipv4/tcp_input.c:3152 [inline] tcp_ack+0x1bea/0x58f0 net/ipv4/tcp_input.c:3688 tcp_rcv_established+0x1820/0x1e70 net/ipv4/tcp_input.c:5712 tcp_v4_do_rcv+0x5d1/0x870 net/ipv4/tcp_ipv4.c:1629 tcp_v4_rcv+0x2cef/0x3760 net/ipv4/tcp_ipv4.c:2011 ip_protocol_deliver_rcu+0x5c/0x880 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x20a/0x370 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip_local_deliver+0x1b3/0x200 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:441 [inline] ip_sublist_rcv_finish+0x9a/0x2c0 net/ipv4/ip_input.c:550 ip_list_rcv_finish.constprop.0+0x514/0x6e0 net/ipv4/ip_input.c:600 ip_sublist_rcv net/ipv4/ip_input.c:608 [inline] ip_list_rcv+0x34e/0x488 net/ipv4/ip_input.c:643 __netif_receive_skb_list_ptype net/core/dev.c:5324 [inline] __netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5372 __netif_receive_skb_list net/core/dev.c:5424 [inline] netif_receive_skb_list_internal+0x777/0xd70 net/core/dev.c:5531 gro_normal_list net/core/dev.c:5642 [inline] gro_normal_list net/core/dev.c:5638 [inline] napi_complete_done+0x1f1/0x860 net/core/dev.c:6367 virtqueue_napi_complete+0x2c/0xc0 drivers/net/virtio_net.c:329 virtnet_poll+0xae0/0xd76 drivers/net/virtio_net.c:1455 napi_poll net/core/dev.c:6684 [inline] net_rx_action+0x4a1/0xe60 net/core/dev.c:6752 __do_softirq+0x34c/0xa60 kernel/softirq.c:292 The buggy address belongs to the object at ffff88809f0ec000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 4 bytes to the right of 1024-byte region [ffff88809f0ec000, ffff88809f0ec400) The buggy address belongs to the page: page:ffffea00027c3b00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002587dc8 ffffea00027c8e08 ffff8880aa000c40 raw: 0000000000000000 ffff88809f0ec000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809f0ec300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88809f0ec380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88809f0ec400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88809f0ec480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809f0ec500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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