================================================================== BUG: KASAN: slab-use-after-free in hci_uart_write_work+0x2ca/0x550 drivers/bluetooth/hci_ldisc.c:165 Read of size 8 at addr ffff88801f2bc218 by task kworker/0:4/5462 CPU: 0 UID: 0 PID: 5462 Comm: kworker/0:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events hci_uart_write_work Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 hci_uart_write_work+0x2ca/0x550 drivers/bluetooth/hci_ldisc.c:165 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 46: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4962 [inline] slab_alloc_node mm/slub.c:5272 [inline] kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5324 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1383 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:510 [inline] hci_cmd_sync_alloc+0x3d/0x380 net/bluetooth/hci_sync.c:58 hci_cmd_sync_add net/bluetooth/hci_sync.c:99 [inline] __hci_cmd_sync_sk+0x1a7/0xbc0 net/bluetooth/hci_sync.c:168 __hci_cmd_sync_status_sk net/bluetooth/hci_sync.c:263 [inline] __hci_cmd_sync_status net/bluetooth/hci_sync.c:287 [inline] hci_read_local_features_sync net/bluetooth/hci_sync.c:3703 [inline] hci_init_stage_sync net/bluetooth/hci_sync.c:3618 [inline] hci_init1_sync net/bluetooth/hci_sync.c:3750 [inline] hci_init_sync net/bluetooth/hci_sync.c:4862 [inline] hci_dev_init_sync net/bluetooth/hci_sync.c:5054 [inline] hci_dev_open_sync+0x14be/0x2b60 net/bluetooth/hci_sync.c:5132 hci_dev_do_open net/bluetooth/hci_core.c:430 [inline] hci_power_on+0x1b4/0x680 net/bluetooth/hci_core.c:959 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 8113: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2530 [inline] slab_free mm/slub.c:6619 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6729 kfree_skb_reason include/linux/skbuff.h:1322 [inline] kfree_skb include/linux/skbuff.h:1331 [inline] hci_uart_flush+0x9d/0x1b0 drivers/bluetooth/hci_ldisc.c:235 hci_uart_close drivers/bluetooth/hci_ldisc.c:268 [inline] hci_uart_tty_close+0x99/0x290 drivers/bluetooth/hci_ldisc.c:545 tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613 tty_ldisc_hangup+0x3a2/0x4b0 drivers/tty/tty_ldisc.c:729 __tty_hangup+0x40c/0x680 drivers/tty/tty_io.c:621 tty_vhangup drivers/tty/tty_io.c:691 [inline] tty_ioctl+0x757/0xde0 drivers/tty/tty_io.c:2732 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88801f2bc140 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 216 bytes inside of freed 240-byte region [ffff88801f2bc140, ffff88801f2bc230) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1f2bc flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff8880304cfc80 ffffea0000008b40 dead000000000004 raw: 0000000000000000 00000000000c000c 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5480, tgid 5480 (syz-executor), ts 215388691880, free_ts 213579489844 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3046 [inline] allocate_slab+0x96/0x3a0 mm/slub.c:3219 new_slab mm/slub.c:3273 [inline] ___slab_alloc+0xe94/0x18a0 mm/slub.c:4643 __slab_alloc+0x65/0x100 mm/slub.c:4762 __slab_alloc_node mm/slub.c:4838 [inline] slab_alloc_node mm/slub.c:5260 [inline] kmem_cache_alloc_node_noprof+0x4c5/0x710 mm/slub.c:5324 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1383 [inline] nlmsg_new include/net/netlink.h:1055 [inline] rtmsg_ifinfo_build_skb+0x84/0x260 net/core/rtnetlink.c:4400 rtmsg_ifinfo_event net/core/rtnetlink.c:4442 [inline] rtmsg_ifinfo+0x8c/0x1a0 net/core/rtnetlink.c:4451 register_netdevice+0x1712/0x1ae0 net/core/dev.c:11346 register_netdev+0x40/0x60 net/core/dev.c:11410 ip6_tnl_init_net+0x259/0x3b0 net/ipv6/ip6_tunnel.c:2307 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137 setup_net+0xfe/0x320 net/core/net_namespace.c:445 page last free pid 5404 tgid 5404 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906 vfree+0x25a/0x400 mm/vmalloc.c:3440 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x28/0x50 kernel/kcov.c:535 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88801f2bc100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff88801f2bc180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801f2bc200: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc ^ ffff88801f2bc280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801f2bc300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ==================================================================