Hello, syzbot found the following issue on: HEAD commit: ac3a0c84 Merge git://git.kernel.org/pub/scm/linux/kernel/g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17082904900000 kernel config: https://syzkaller.appspot.com/x/.config?x=e59ee776d5aa8d55 dashboard link: https://syzkaller.appspot.com/bug?extid=077eca30d3cb7c02b273 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12cf1904900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10d52e14900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+077eca30d3cb7c02b273@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:71 [inline] BUG: KASAN: use-after-free in atomic_dec_and_test include/asm-generic/atomic-instrumented.h:748 [inline] BUG: KASAN: use-after-free in hci_conn_drop include/net/bluetooth/hci_core.h:1049 [inline] BUG: KASAN: use-after-free in sco_chan_del net/bluetooth/sco.c:148 [inline] BUG: KASAN: use-after-free in __sco_sock_close+0x47c/0xed0 net/bluetooth/sco.c:433 Write of size 4 at addr ffff88809191e010 by task syz-executor393/6961 CPU: 0 PID: 6961 Comm: syz-executor393 Not tainted 5.8.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1f0/0x31e lib/dump_stack.c:118 print_address_description+0x66/0x5a0 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report+0x132/0x1d0 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:183 [inline] check_memory_region+0x2b5/0x2f0 mm/kasan/generic.c:192 instrument_atomic_write include/linux/instrumented.h:71 [inline] atomic_dec_and_test include/asm-generic/atomic-instrumented.h:748 [inline] hci_conn_drop include/net/bluetooth/hci_core.h:1049 [inline] sco_chan_del net/bluetooth/sco.c:148 [inline] __sco_sock_close+0x47c/0xed0 net/bluetooth/sco.c:433 sco_sock_close net/bluetooth/sco.c:447 [inline] sco_sock_release+0x63/0x4f0 net/bluetooth/sco.c:1021 __sock_release net/socket.c:605 [inline] sock_close+0xd8/0x260 net/socket.c:1278 __fput+0x2f0/0x750 fs/file_table.c:281 task_work_run+0x137/0x1c0 kernel/task_work.c:135 exit_task_work include/linux/task_work.h:25 [inline] do_exit+0x601/0x1f80 kernel/exit.c:805 do_group_exit+0x161/0x2d0 kernel/exit.c:903 get_signal+0x139b/0x1d30 kernel/signal.c:2743 do_signal+0x33/0x610 arch/x86/kernel/signal.c:810 exit_to_usermode_loop arch/x86/entry/common.c:235 [inline] __prepare_exit_to_usermode+0xd7/0x1e0 arch/x86/entry/common.c:269 do_syscall_64+0x7f/0xe0 arch/x86/entry/common.c:393 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x446e69 Code: Bad RIP value. RSP: 002b:00007ffde45fd7f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffffc RBX: 0000000000000000 RCX: 0000000000446e69 RDX: 0000000000000008 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 0000000000000004 R08: 0000000000000002 R09: 00000003000000ff R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000407ac0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6961: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x103/0x140 mm/kasan/common.c:494 kmem_cache_alloc_trace+0x234/0x300 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] hci_conn_add+0x5d/0x1040 net/bluetooth/hci_conn.c:525 hci_connect_sco+0x29a/0xa10 net/bluetooth/hci_conn.c:1279 sco_connect net/bluetooth/sco.c:240 [inline] sco_sock_connect+0x2de/0xaa0 net/bluetooth/sco.c:576 __sys_connect_file net/socket.c:1854 [inline] __sys_connect+0x2da/0x360 net/socket.c:1871 __do_sys_connect net/socket.c:1882 [inline] __se_sys_connect net/socket.c:1879 [inline] __x64_sys_connect+0x76/0x80 net/socket.c:1879 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 6957: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x220 mm/slab.c:3757 device_release+0x70/0x1a0 drivers/base/core.c:1575 kobject_cleanup lib/kobject.c:693 [inline] kobject_release lib/kobject.c:722 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x15b/0x220 lib/kobject.c:739 hci_conn_del+0x2c2/0x550 net/bluetooth/hci_conn.c:645 hci_phy_link_complete_evt net/bluetooth/hci_event.c:4921 [inline] hci_event_packet+0x8335/0x18260 net/bluetooth/hci_event.c:6180 hci_rx_work+0x236/0x9c0 net/bluetooth/hci_core.c:4705 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff88809191e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 16 bytes inside of 4096-byte region [ffff88809191e000, ffff88809191f000) The buggy address belongs to the page: page:ffffea0002464780 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea0002464780 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0002489f88 ffffea000249dd08 ffff8880aa402000 raw: 0000000000000000 ffff88809191e000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809191df00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809191df80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88809191e000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809191e080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809191e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. 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