syzbot

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BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x22a/0x240 net/bluetooth/l2cap_sock.c:1483
Read of size 8 at addr ffff8880343de580 by task kworker/u9:7/5838

CPU: 1 UID: 0 PID: 5838 Comm: kworker/u9:7 Not tainted 6.12.0-rc7-syzkaller-00125-gcfaaa7d010d1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Workqueue: hci3 hci_rx_work
Call Trace:
 <TASK>
 __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:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 l2cap_sock_new_connection_cb+0x22a/0x240 net/bluetooth/l2cap_sock.c:1483
 l2cap_connect_cfm+0x4c9/0xf80 net/bluetooth/l2cap_core.c:7261
 hci_connect_cfm include/net/bluetooth/hci_core.h:1960 [inline]
 le_conn_complete_evt+0x1662/0x1d80 net/bluetooth/hci_event.c:5758
 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5784
 hci_le_meta_evt+0x2e2/0x5d0 net/bluetooth/hci_event.c:7132
 hci_event_func net/bluetooth/hci_event.c:7440 [inline]
 hci_event_packet+0x666/0x1180 net/bluetooth/hci_event.c:7495
 hci_rx_work+0x2c6/0x1610 net/bluetooth/hci_core.c:4029
 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
 </TASK>

Allocated by task 5838:
 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
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_noprof+0x1e8/0x400 mm/slub.c:4276
 kmalloc_noprof include/linux/slab.h:882 [inline]
 sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2170
 sk_alloc+0x36/0xb90 net/core/sock.c:2223
 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:148
 l2cap_sock_alloc.constprop.0+0x35/0x180 net/bluetooth/l2cap_sock.c:1877
 l2cap_sock_new_connection_cb+0x101/0x240 net/bluetooth/l2cap_sock.c:1468
 l2cap_connect_cfm+0x4c9/0xf80 net/bluetooth/l2cap_core.c:7261
 hci_connect_cfm include/net/bluetooth/hci_core.h:1960 [inline]
 le_conn_complete_evt+0x1662/0x1d80 net/bluetooth/hci_event.c:5758
 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5784
 hci_le_meta_evt+0x2e2/0x5d0 net/bluetooth/hci_event.c:7132
 hci_event_func net/bluetooth/hci_event.c:7440 [inline]
 hci_event_packet+0x666/0x1180 net/bluetooth/hci_event.c:7495
 hci_rx_work+0x2c6/0x1610 net/bluetooth/hci_core.c:4029
 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

Freed by task 11650:
 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:230 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kfree+0x14f/0x4b0 mm/slub.c:4727
 sk_prot_free net/core/sock.c:2206 [inline]
 __sk_destruct+0x5eb/0x720 net/core/sock.c:2298
 sk_destruct+0xc2/0xf0 net/core/sock.c:2313
 __sk_free+0xf4/0x3e0 net/core/sock.c:2324
 sk_free+0x6a/0x90 net/core/sock.c:2335
 sock_put include/net/sock.h:1888 [inline]
 l2cap_sock_kill net/bluetooth/l2cap_sock.c:1250 [inline]
 l2cap_sock_kill+0x171/0x2d0 net/bluetooth/l2cap_sock.c:1235
 l2cap_sock_cleanup_listen+0x3d/0x2a0 net/bluetooth/l2cap_sock.c:1448
 l2cap_sock_release+0x5c/0x210 net/bluetooth/l2cap_sock.c:1411
 __sock_release+0xb0/0x270 net/socket.c:658
 sock_close+0x1c/0x30 net/socket.c:1426
 __fput+0x3f6/0xb60 fs/file_table.c:431
 task_work_run+0x14e/0x250 kernel/task_work.c:239
 get_signal+0x1ca/0x2770 kernel/signal.c:2691
 arch_do_signal_or_restart+0x90/0x7e0 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:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880343de000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1408 bytes inside of
 freed 2048-byte region [ffff8880343de000, ffff8880343de800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x343d8
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 ffff88801b042000 ffffea0000ae3e00 dead000000000002
raw: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff88801b042000 ffffea0000ae3e00 dead000000000002
head: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea0000d0f601 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5824, tgid 5824 (syz-executor), ts 57222746513, free_ts 57154844900
 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:4750
 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_track_caller_noprof+0x355/0x430 mm/slub.c:4283
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:609
 __alloc_skb+0x164/0x380 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1322 [inline]
 nlmsg_new include/net/netlink.h:1015 [inline]
 inet6_ifinfo_notify+0x77/0x150 net/ipv6/addrconf.c:6163
 addrconf_notify+0x81a/0x19c0 net/ipv6/addrconf.c:3765
 notifier_call_chain+0xb9/0x410 kernel/notifier.c:93
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1996
 call_netdevice_notifiers_extack net/core/dev.c:2034 [inline]
 call_netdevice_notifiers net/core/dev.c:2048 [inline]
 __dev_notify_flags+0x12d/0x2e0 net/core/dev.c:8884
 dev_change_flags+0x10c/0x160 net/core/dev.c:8922
page last free pid 5878 tgid 5878 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0x661/0x1080 mm/page_alloc.c:2657
 __put_partials+0x14c/0x170 mm/slub.c:3145
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4085 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4141
 vm_area_alloc+0x1f/0x230 kernel/fork.c:473
 __mmap_region+0xee0/0x21c0 mm/mmap.c:1435
 mmap_region+0x127/0x320 mm/mmap.c:1603
 do_mmap+0xc00/0xfc0 mm/mmap.c:496
 vm_mmap_pgoff+0x1ba/0x360 mm/util.c:588
 ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:542
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:79 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:79
 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

Memory state around the buggy address:
 ffff8880343de480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880343de500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880343de580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8880343de600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880343de680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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