syzbot

==================================================================
BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0x92/0x190 lib/list_debug.c:62
Read of size 8 at addr ffff888057126550 by task syz-executor/7429

CPU: 0 UID: 0 PID: 7429 Comm: syz-executor Not tainted 6.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:489
 kasan_report+0x143/0x180 mm/kasan/report.c:602
 __list_del_entry_valid_or_report+0x92/0x190 lib/list_debug.c:62
 __list_del_entry_valid include/linux/list.h:124 [inline]
 __list_del_entry include/linux/list.h:215 [inline]
 list_del_init include/linux/list.h:287 [inline]
 bt_accept_unlink+0x39/0x250 net/bluetooth/af_bluetooth.c:256
 l2cap_sock_teardown_cb+0x176/0x440 net/bluetooth/l2cap_sock.c:1600
 l2cap_chan_del+0xba/0x5d0 net/bluetooth/l2cap_core.c:654
 l2cap_conn_del+0x391/0x690 net/bluetooth/l2cap_core.c:1785
 hci_disconn_cfm include/net/bluetooth/hci_core.h:2069 [inline]
 hci_conn_hash_flush+0x1c0/0x350 net/bluetooth/hci_conn.c:2698
 hci_dev_close_sync+0xa8b/0x1260 net/bluetooth/hci_sync.c:5197
 hci_dev_do_close net/bluetooth/hci_core.c:482 [inline]
 hci_unregister_dev+0x20b/0x510 net/bluetooth/hci_core.c:2677
 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:664
 __fput+0x3eb/0x9f0 fs/file_table.c:464
 task_work_run+0x251/0x310 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa2a/0x28e0 kernel/exit.c:938
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 get_signal+0x168c/0x1720 kernel/signal.c:3036
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f23d79bf6a5
Code: Unable to access opcode bytes at 0x7f23d79bf67b.
RSP: 002b:00007ffda2e2cae0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 0000000000000726 RCX: 00007f23d79bf6a5
RDX: 00007ffda2e2cb20 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffda2e2cb8c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388
R13: 00000000000927c0 R14: 0000000000152a34 R15: 00007ffda2e2cbe0
 </TASK>

Allocated by task 2146:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4294 [inline]
 __kmalloc_node_track_caller_noprof+0x28b/0x4c0 mm/slub.c:4313
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1331 [inline]
 mld_newpack+0x17c/0xc70 net/ipv6/mcast.c:1788
 add_grhead net/ipv6/mcast.c:1899 [inline]
 add_grec+0x1492/0x19a0 net/ipv6/mcast.c:2037
 mld_send_cr net/ipv6/mcast.c:2163 [inline]
 mld_ifc_work+0x691/0xd90 net/ipv6/mcast.c:2702
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3317
 worker_thread+0x870/0xd30 kernel/workqueue.c:3398
 kthread+0x7ab/0x920 kernel/kthread.c:464
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 2146:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kfree+0x196/0x430 mm/slub.c:4757
 skb_kfree_head net/core/skbuff.c:1086 [inline]
 skb_free_head net/core/skbuff.c:1098 [inline]
 skb_release_data+0x6a0/0x8a0 net/core/skbuff.c:1125
 skb_release_all net/core/skbuff.c:1190 [inline]
 __kfree_skb net/core/skbuff.c:1204 [inline]
 sk_skb_reason_drop+0x1c9/0x380 net/core/skbuff.c:1242
 kfree_skb_reason include/linux/skbuff.h:1271 [inline]
 kfree_skb include/linux/skbuff.h:1280 [inline]
 ip6_mc_input+0x974/0xb70 net/ipv6/ip6_input.c:591
 NF_HOOK+0x3a6/0x450 include/linux/netfilter.h:314
 __netif_receive_skb_one_core net/core/dev.c:5828 [inline]
 __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5941
 process_backlog+0x662/0x15b0 net/core/dev.c:6289
 __napi_poll+0xcd/0x490 net/core/dev.c:7106
 napi_poll net/core/dev.c:7175 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:7297
 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:561
 do_softirq+0x11b/0x1e0 kernel/softirq.c:462
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:389
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline]
 __dev_queue_xmit+0x1775/0x3f50 net/core/dev.c:4611
 dev_queue_xmit include/linux/netdevice.h:3311 [inline]
 neigh_hh_output include/net/neighbour.h:523 [inline]
 neigh_output include/net/neighbour.h:537 [inline]
 ip6_finish_output2+0x127d/0x17c0 net/ipv6/ip6_output.c:141
 ip6_finish_output+0x41e/0x840 net/ipv6/ip6_output.c:226
 NF_HOOK+0x9e/0x430 include/linux/netfilter.h:314
 mld_sendpack+0x843/0xdb0 net/ipv6/mcast.c:1868
 mld_send_cr net/ipv6/mcast.c:2169 [inline]
 mld_ifc_work+0x7d9/0xd90 net/ipv6/mcast.c:2702
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3317
 worker_thread+0x870/0xd30 kernel/workqueue.c:3398
 kthread+0x7ab/0x920 kernel/kthread.c:464
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff888057126000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1360 bytes inside of
 freed 2048-byte region [ffff888057126000, ffff888057126800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888057123000 pfn:0x57120
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88801b042000 ffffea000084be10 ffffea00015b0c10
raw: ffff888057123000 0000000000080007 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801b042000 ffffea000084be10 ffffea00015b0c10
head: ffff888057123000 0000000000080007 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea00015c4801 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 5832, tgid 5832 (syz-executor), ts 77500910407, free_ts 23735187118
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739
 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab+0x8f/0x3a0 mm/slub.c:2587
 new_slab mm/slub.c:2640 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
 __slab_alloc+0x58/0xa0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 __do_kmalloc_node mm/slub.c:4293 [inline]
 __kmalloc_node_noprof+0x2ee/0x4d0 mm/slub.c:4300
 kmalloc_node_noprof include/linux/slab.h:928 [inline]
 qdisc_alloc+0x9a/0xa80 net/sched/sch_generic.c:947
 qdisc_create_dflt+0x62/0x4b0 net/sched/sch_generic.c:1009
 attach_one_default_qdisc net/sched/sch_generic.c:1175 [inline]
 netdev_for_each_tx_queue include/linux/netdevice.h:2590 [inline]
 attach_default_qdiscs net/sched/sch_generic.c:1193 [inline]
 dev_activate+0x3c0/0x1240 net/sched/sch_generic.c:1252
 __dev_open+0x38e/0x4a0 net/core/dev.c:1613
 __dev_change_flags+0x1e2/0x6f0 net/core/dev.c:9172
 dev_change_flags+0x8b/0x1a0 net/core/dev.c:9244
 do_setlink+0xcca/0x4300 net/core/rtnetlink.c:3118
 rtnl_changelink net/core/rtnetlink.c:3733 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3885 [inline]
 rtnl_newlink+0x1704/0x1d30 net/core/rtnetlink.c:4022
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660
 free_contig_range+0x14c/0x430 mm/page_alloc.c:6678
 destroy_args+0x94/0x4b0 mm/debug_vm_pgtable.c:1017
 debug_vm_pgtable+0x551/0x590 mm/debug_vm_pgtable.c:1397
 do_one_initcall+0x24a/0x930 init/main.c:1257
 do_initcall_level+0x157/0x210 init/main.c:1319
 do_initcalls+0x71/0xd0 init/main.c:1335
 kernel_init_freeable+0x435/0x5d0 init/main.c:1568
 kernel_init+0x1d/0x2b0 init/main.c:1457
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff888057126400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888057126480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888057126500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff888057126580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888057126600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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