================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: slab-use-after-free in atomic_long_read include/linux/atomic/atomic-instrumented.h:3188 [inline] BUG: KASAN: slab-use-after-free in __mutex_unlock_slowpath+0xaf/0x790 kernel/locking/mutex.c:947 Read of size 8 at addr ffff888043c66ad0 by task kworker/2:1/14762 CPU: 2 UID: 0 PID: 14762 Comm: kworker/2:1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events l2cap_chan_timeout Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:194 [inline] kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:200 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_long_read include/linux/atomic/atomic-instrumented.h:3188 [inline] __mutex_unlock_slowpath+0xaf/0x790 kernel/locking/mutex.c:947 l2cap_chan_timeout+0x202/0x340 net/bluetooth/l2cap_core.c:438 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 22579: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] l2cap_conn_add.part.0+0x60/0xa90 net/bluetooth/l2cap_core.c:6887 l2cap_conn_add include/net/bluetooth/hci_core.h:1686 [inline] l2cap_chan_connect+0x1691/0x2150 net/bluetooth/l2cap_core.c:7078 l2cap_sock_connect+0x3ba/0x770 net/bluetooth/l2cap_sock.c:256 kernel_connect+0x107/0x180 net/socket.c:3634 rfcomm_session_create net/bluetooth/rfcomm/core.c:811 [inline] __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:388 [inline] rfcomm_dlc_open+0x84a/0xaf0 net/bluetooth/rfcomm/core.c:431 rfcomm_sock_connect+0x423/0x6a0 net/bluetooth/rfcomm/sock.c:410 __sys_connect_file+0x141/0x1a0 net/socket.c:2089 __sys_connect+0x13b/0x160 net/socket.c:2108 __do_sys_connect net/socket.c:2114 [inline] __se_sys_connect net/socket.c:2111 [inline] __ia32_sys_connect+0x71/0xb0 net/socket.c:2111 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe8/0x680 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 22832: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6668 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6876 l2cap_conn_free net/bluetooth/l2cap_core.c:1812 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put net/bluetooth/l2cap_core.c:1824 [inline] l2cap_conn_del+0x5c7/0x760 net/bluetooth/l2cap_core.c:1804 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7326 [inline] l2cap_disconn_cfm+0x95/0xf0 net/bluetooth/l2cap_core.c:7319 hci_disconn_cfm include/net/bluetooth/hci_core.h:2146 [inline] hci_conn_hash_flush+0x10e/0x290 net/bluetooth/hci_conn.c:2637 hci_dev_close_sync+0x601/0x1260 net/bluetooth/hci_sync.c:5326 hci_dev_do_close+0x2e/0xc0 net/bluetooth/hci_core.c:501 hci_unregister_dev+0x227/0x680 net/bluetooth/hci_core.c:2715 vhci_release+0x17d/0x230 drivers/bluetooth/hci_vhci.c:690 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x87f/0x2bd0 kernel/exit.c:971 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x38a/0x8c0 kernel/entry/common.c:196 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 The buggy address belongs to the object at ffff888043c66800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 720 bytes inside of freed 1024-byte region [ffff888043c66800, ffff888043c66c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43c60 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff88801b442dc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 04fff00000000040 ffff88801b442dc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 04fff00000000003 ffffea00010f1801 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5946, tgid 5946 (syz-executor), ts 55131709320, free_ts 55121485379 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c3/0x430 mm/slub.c:3302 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_node_noprof+0x4d8/0x930 mm/slub.c:5663 kmalloc_node_noprof include/linux/slab.h:987 [inline] qdisc_alloc+0xb7/0xa50 net/sched/sch_generic.c:951 qdisc_create_dflt+0x94/0x460 net/sched/sch_generic.c:1008 attach_one_default_qdisc net/sched/sch_generic.c:1174 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2680 [inline] attach_default_qdiscs net/sched/sch_generic.c:1192 [inline] dev_activate+0x63f/0x12d0 net/sched/sch_generic.c:1251 __dev_open+0x4f1/0x960 net/core/dev.c:1692 __dev_change_flags+0x55d/0x6f0 net/core/dev.c:9734 netif_change_flags+0x8d/0x160 net/core/dev.c:9797 do_setlink.constprop.0+0xb53/0x4380 net/core/rtnetlink.c:3158 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x1376/0x1f50 net/core/rtnetlink.c:4072 page last free pid 5941 tgid 5941 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943 discard_slab mm/slub.c:3346 [inline] __put_partials+0x130/0x170 mm/slub.c:3886 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4c/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:349 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] __kmalloc_cache_noprof+0x282/0x800 mm/slub.c:5771 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] inet_alloc_ifa+0x43/0x190 net/ipv4/devinet.c:212 inet_rtm_to_ifa net/ipv4/devinet.c:904 [inline] inet_rtm_newaddr+0x3b5/0x1540 net/ipv4/devinet.c:980 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x4a3/0x520 net/socket.c:2206 __do_compat_sys_socketcall net/compat.c:475 [inline] __se_compat_sys_socketcall net/compat.c:423 [inline] __ia32_compat_sys_socketcall+0x62a/0x780 net/compat.c:423 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe8/0x680 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332 Memory state around the buggy address: ffff888043c66980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888043c66a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888043c66a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888043c66b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888043c66b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================