================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x2d90/0x3c40 kernel/locking/lockdep.c:5089 Read of size 8 at addr ffff888044ecaaf0 by task kworker/2:1/63 CPU: 2 UID: 0 PID: 63 Comm: kworker/2:1 Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 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+0xc3/0x620 mm/kasan/report.c:489 kasan_report+0xd9/0x110 mm/kasan/report.c:602 __lock_acquire+0x2d90/0x3c40 kernel/locking/lockdep.c:5089 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __mutex_lock_common kernel/locking/mutex.c:599 [inline] __mutex_lock+0x297/0xa60 kernel/locking/mutex.c:735 l2cap_chan_timeout+0x6d/0x310 net/bluetooth/l2cap_core.c:421 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 7341: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:879 [inline] kzalloc_noprof include/linux/slab.h:1015 [inline] l2cap_conn_add.part.0+0x60/0xa60 net/bluetooth/l2cap_core.c:6860 l2cap_conn_add include/net/bluetooth/hci_core.h:1619 [inline] l2cap_chan_connect+0x15e8/0x2010 net/bluetooth/l2cap_core.c:7051 l2cap_sock_connect+0x3b8/0x740 net/bluetooth/l2cap_sock.c:256 __sys_connect_file+0x13e/0x1a0 net/socket.c:2055 __sys_connect+0x14f/0x170 net/socket.c:2074 __do_sys_connect net/socket.c:2080 [inline] __se_sys_connect net/socket.c:2077 [inline] __x64_sys_connect+0x72/0xb0 net/socket.c:2077 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5895: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kfree+0x14f/0x4b0 mm/slub.c:4727 l2cap_conn_free net/bluetooth/l2cap_core.c:1810 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put net/bluetooth/l2cap_core.c:1822 [inline] l2cap_conn_del+0x59d/0x730 net/bluetooth/l2cap_core.c:1802 l2cap_connect_cfm+0x9e6/0xf80 net/bluetooth/l2cap_core.c:7233 hci_connect_cfm include/net/bluetooth/hci_core.h:2035 [inline] hci_conn_failed+0x1ba/0x330 net/bluetooth/hci_conn.c:1266 hci_abort_conn_sync+0x745/0xb40 net/bluetooth/hci_sync.c:5603 abort_conn_sync+0x197/0x360 net/bluetooth/hci_conn.c:3023 hci_cmd_sync_work+0x1a4/0x410 net/bluetooth/hci_sync.c:332 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff888044eca800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 752 bytes inside of freed 1024-byte region [ffff888044eca800, ffff888044ecac00) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x44ec8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b042dc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801b042dc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 head: 00fff00000000003 ffffea000113b201 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 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 6093, tgid 6093 (syz-executor.3), ts 51961791463, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1556 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3474 __alloc_pages_noprof+0x223/0x25a0 mm/page_alloc.c:4751 alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2265 alloc_slab_page mm/slub.c:2412 [inline] allocate_slab mm/slub.c:2578 [inline] new_slab+0x2c9/0x410 mm/slub.c:2631 ___slab_alloc+0xdac/0x1880 mm/slub.c:3818 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3908 __slab_alloc_node mm/slub.c:3961 [inline] slab_alloc_node mm/slub.c:4122 [inline] __do_kmalloc_node mm/slub.c:4263 [inline] __kmalloc_node_noprof+0x357/0x430 mm/slub.c:4270 kmalloc_node_noprof include/linux/slab.h:906 [inline] qdisc_alloc+0xbb/0xc50 net/sched/sch_generic.c:952 qdisc_create_dflt+0x73/0x430 net/sched/sch_generic.c:1014 attach_one_default_qdisc net/sched/sch_generic.c:1180 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2562 [inline] attach_default_qdiscs net/sched/sch_generic.c:1198 [inline] dev_activate+0x63a/0x12b0 net/sched/sch_generic.c:1257 __dev_open+0x396/0x4e0 net/core/dev.c:1485 __dev_change_flags+0x561/0x720 net/core/dev.c:8943 dev_change_flags+0x8f/0x160 net/core/dev.c:9015 do_setlink.constprop.0+0x69c/0x3f70 net/core/rtnetlink.c:3103 rtnl_changelink net/core/rtnetlink.c:3717 [inline] __rtnl_newlink net/core/rtnetlink.c:3869 [inline] rtnl_newlink+0x12c7/0x1c50 net/core/rtnetlink.c:4001 page_owner free stack trace missing Memory state around the buggy address: ffff888044eca980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888044ecaa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888044ecaa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888044ecab00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888044ecab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================