================================================================== BUG: KASAN: use-after-free in atomic_inc include/asm-generic/atomic-instrumented.h:239 [inline] BUG: KASAN: use-after-free in hci_sock_bind+0x591/0x1140 net/bluetooth/hci_sock.c:1250 Write of size 4 at addr ffff88803ba8d250 by task syz-executor.3/11064 CPU: 1 PID: 11064 Comm: syz-executor.3 Not tainted 5.7.0-rc2-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+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:382 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:511 kasan_report+0x33/0x50 mm/kasan/common.c:625 check_memory_region_inline mm/kasan/generic.c:187 [inline] check_memory_region+0x141/0x190 mm/kasan/generic.c:193 atomic_inc include/asm-generic/atomic-instrumented.h:239 [inline] hci_sock_bind+0x591/0x1140 net/bluetooth/hci_sock.c:1250 __sys_bind+0x20e/0x250 net/socket.c:1662 __do_sys_bind net/socket.c:1673 [inline] __se_sys_bind net/socket.c:1671 [inline] __x64_sys_bind+0x6f/0xb0 net/socket.c:1671 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f39fd57bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 00000000004d95c0 RCX: 000000000045c829 RDX: 0000000000000006 RSI: 0000000020000080 RDI: 0000000000000007 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 000000000000002c R14: 00000000004c2cd9 R15: 00007f39fd57c6d4 Allocated by task 11064: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468 kmem_cache_alloc_trace+0x153/0x7d0 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] hci_alloc_dev+0x3e/0x1ff0 net/bluetooth/hci_core.c:3365 __vhci_create_device+0x100/0x5b0 drivers/bluetooth/hci_vhci.c:99 vhci_create_device drivers/bluetooth/hci_vhci.c:148 [inline] vhci_get_user drivers/bluetooth/hci_vhci.c:205 [inline] vhci_write+0x2bf/0x450 drivers/bluetooth/hci_vhci.c:285 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write+0x4a2/0x700 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+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 11063: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] kasan_set_free_info mm/kasan/common.c:317 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 bt_host_release+0x15/0x20 net/bluetooth/hci_sysfs.c:86 device_release+0x71/0x200 drivers/base/core.c:1375 kobject_cleanup lib/kobject.c:693 [inline] kobject_release lib/kobject.c:722 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1e7/0x2e0 lib/kobject.c:739 put_device+0x1b/0x30 drivers/base/core.c:2632 vhci_release+0x78/0xe0 drivers/bluetooth/hci_vhci.c:341 __fput+0x33e/0x880 fs/file_table.c:280 task_work_run+0xf4/0x1b0 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 The buggy address belongs to the object at ffff88803ba8c000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 4688 bytes inside of 8192-byte region [ffff88803ba8c000, ffff88803ba8e000) The buggy address belongs to the page: page:ffffea0000eea300 refcount:1 mapcount:0 mapping:0000000092e8f3b8 index:0x0 head:ffffea0000eea300 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0000ee9308 ffffea0001238908 ffff8880aa0021c0 raw: 0000000000000000 ffff88803ba8c000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88803ba8d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803ba8d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803ba8d200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803ba8d280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803ba8d300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================