================================================================== BUG: KASAN: use-after-free in hci_conn_del+0x64e/0x6a0 net/bluetooth/hci_conn.c:630 Write of size 8 at addr ffff8880a29bc938 by task syz-executor.2/7013 CPU: 0 PID: 7013 Comm: syz-executor.2 Not tainted 5.9.0-rc3-next-20200903-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+0x198/0x1fd lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 hci_conn_del+0x64e/0x6a0 net/bluetooth/hci_conn.c:630 hci_conn_hash_flush+0x189/0x220 net/bluetooth/hci_conn.c:1558 hci_dev_do_close+0x5c6/0x1080 net/bluetooth/hci_core.c:1770 hci_unregister_dev+0x214/0xe90 net/bluetooth/hci_core.c:3801 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:340 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:141 exit_task_work include/linux/task_work.h:25 [inline] do_exit+0xb7d/0x29f0 kernel/exit.c:806 do_group_exit+0x125/0x310 kernel/exit.c:903 __do_sys_exit_group kernel/exit.c:914 [inline] __se_sys_exit_group kernel/exit.c:912 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:912 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45ce79 Code: Bad RIP value. RSP: 002b:00007fffb51afa08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045ce79 RDX: 00000000004168d1 RSI: 00000000016a85f0 RDI: 0000000000000043 RBP: 00000000004c2b1b R08: 000000000000000b R09: 0000000000000000 R10: 00000000024b0940 R11: 0000000000000246 R12: 000000000000000e R13: 00007fffb51afb50 R14: 000000000001539b R15: 00007fffb51afb60 Allocated by task 7021: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x1b0/0x310 mm/slab.c:3664 kmalloc include/linux/slab.h:559 [inline] tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x1cb/0x4d0 security/tomoyo/file.c:723 security_file_ioctl+0x50/0xb0 security/security.c:1480 __do_sys_ioctl fs/ioctl.c:747 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0xb3/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 7021: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3418 [inline] kfree+0x10e/0x2b0 mm/slab.c:3756 tomoyo_realpath_from_path+0x191/0x620 security/tomoyo/realpath.c:291 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x1cb/0x4d0 security/tomoyo/file.c:723 security_file_ioctl+0x50/0xb0 security/security.c:1480 __do_sys_ioctl fs/ioctl.c:747 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0xb3/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880a29bc000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2360 bytes inside of 4096-byte region [ffff8880a29bc000, ffff8880a29bd000) The buggy address belongs to the page: page:0000000088f01a2e refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa29bc head:0000000088f01a2e order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea00028edb88 ffffea00025e0c08 ffff8880aa040900 raw: 0000000000000000 ffff8880a29bc000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a29bc800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a29bc880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a29bc900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a29bc980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a29bca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================