Hello, syzbot found the following issue on: HEAD commit: ce8056d1 wip: changed copy_from_user where instrumented git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=16c0e1e2900000 kernel config: https://syzkaller.appspot.com/x/.config?x=3afe005fb99591f dashboard link: https://syzkaller.appspot.com/bug?extid=4c14a8f574461e1c3659 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16fd6aa6900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=105910ce900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+4c14a8f574461e1c3659@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== BUG: KMSAN: uninit-value in __hci_chan_lookup_handle net/bluetooth/hci_conn.c:1741 [inline] BUG: KMSAN: uninit-value in hci_chan_lookup_handle+0x1e3/0x310 net/bluetooth/hci_conn.c:1757 CPU: 0 PID: 8496 Comm: kworker/u5:2 Not tainted 5.8.0-rc5-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+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 __hci_chan_lookup_handle net/bluetooth/hci_conn.c:1741 [inline] hci_chan_lookup_handle+0x1e3/0x310 net/bluetooth/hci_conn.c:1757 hci_disconn_loglink_complete_evt net/bluetooth/hci_event.c:4992 [inline] hci_event_packet+0x14e10/0x39d30 net/bluetooth/hci_event.c:6176 hci_rx_work+0x6df/0xd30 net/bluetooth/hci_core.c:4705 process_one_work+0x1688/0x2140 kernel/workqueue.c:2269 worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415 kthread+0x551/0x590 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80 slab_alloc_node mm/slub.c:2839 [inline] __kmalloc_node_track_caller+0xeab/0x12e0 mm/slub.c:4478 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0x35f/0xb30 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+0x18a/0x890 drivers/bluetooth/hci_vhci.c:285 call_write_iter include/linux/fs.h:1908 [inline] new_sync_write fs/read_write.c:503 [inline] vfs_write+0xf9a/0x17c0 fs/read_write.c:578 ksys_write+0x275/0x500 fs/read_write.c:631 __do_sys_write fs/read_write.c:643 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:640 __x64_sys_write+0x4a/0x70 fs/read_write.c:640 do_syscall_64+0xad/0x160 arch/x86/entry/common.c:386 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ===================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
