syzbot

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BUG: KASAN: use-after-free in l2cap_sock_ready_cb+0xce/0x130 net/bluetooth/l2cap_sock.c:1659
Read of size 8 at addr ffff8880756a04c8 by task kworker/u5:0/146

CPU: 0 PID: 146 Comm: kworker/u5:0 Not tainted 5.15.175-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 l2cap_sock_ready_cb+0xce/0x130 net/bluetooth/l2cap_sock.c:1659
 l2cap_chan_ready net/bluetooth/l2cap_core.c:1385 [inline]
 l2cap_le_start+0x4fa/0x1e60 net/bluetooth/l2cap_core.c:1497
 l2cap_conn_ready net/bluetooth/l2cap_core.c:1766 [inline]
 l2cap_connect_cfm+0x72b/0x1270 net/bluetooth/l2cap_core.c:8289
 hci_connect_cfm include/net/bluetooth/hci_core.h:1505 [inline]
 le_conn_complete_evt+0xd02/0x1500 net/bluetooth/hci_event.c:5432
 hci_le_conn_complete_evt net/bluetooth/hci_event.c:5457 [inline]
 hci_le_meta_evt+0x28c/0x3f50 net/bluetooth/hci_event.c:6178
 hci_event_packet+0xc41/0x1550 net/bluetooth/hci_event.c:6527
 hci_rx_work+0x237/0xa10 net/bluetooth/hci_core.c:5160
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Allocated by task 6680:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 __kmalloc+0x168/0x300 mm/slub.c:4407
 kmalloc include/linux/slab.h:596 [inline]
 sk_prot_alloc+0xe0/0x200 net/core/sock.c:1863
 sk_alloc+0x35/0x310 net/core/sock.c:1916
 l2cap_sock_alloc+0x34/0x1f0 net/bluetooth/l2cap_sock.c:1861
 l2cap_sock_create+0x10d/0x1c0 net/bluetooth/l2cap_sock.c:1908
 bt_sock_create+0x159/0x220 net/bluetooth/af_bluetooth.c:130
 __sock_create+0x460/0x8f0 net/socket.c:1486
 sock_create net/socket.c:1542 [inline]
 __sys_socket+0x132/0x370 net/socket.c:1584
 __do_sys_socket net/socket.c:1593 [inline]
 __se_sys_socket net/socket.c:1591 [inline]
 __x64_sys_socket+0x76/0x80 net/socket.c:1591
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 6680:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kfree+0xf1/0x270 mm/slub.c:4559
 sk_prot_free net/core/sock.c:1899 [inline]
 __sk_destruct+0x58e/0x840 net/core/sock.c:1985
 l2cap_sock_release+0x157/0x1d0 net/bluetooth/l2cap_sock.c:1429
 __sock_release net/socket.c:649 [inline]
 sock_close+0xcd/0x230 net/socket.c:1336
 __fput+0x3fe/0x8e0 fs/file_table.c:280
 task_work_run+0x129/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff8880756a0000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1224 bytes inside of
 2048-byte region [ffff8880756a0000, ffff8880756a0800)
The buggy address belongs to the page:
page:ffffea0001d5a800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x756a0
head:ffffea0001d5a800 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888017442000
raw: 0000000000000000 0000000000080008 00000001ffffffff 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4177, ts 54181426952, free_ts 54142488998
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5465
 alloc_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xbb/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 __kmalloc_node_track_caller+0x1f6/0x390 mm/slub.c:4958
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 pskb_expand_head+0x111/0x1130 net/core/skbuff.c:1709
 netlink_trim+0x183/0x220 net/netlink/af_netlink.c:1293
 netlink_broadcast_filtered+0x62/0x11a0 net/netlink/af_netlink.c:1498
 netlink_broadcast net/netlink/af_netlink.c:1543 [inline]
 nlmsg_multicast include/net/netlink.h:1033 [inline]
 nlmsg_notify+0xf7/0x1b0 net/netlink/af_netlink.c:2532
 rtnl_notify net/core/rtnetlink.c:759 [inline]
 rtmsg_ifinfo_send net/core/rtnetlink.c:3905 [inline]
 rtmsg_ifinfo_event net/core/rtnetlink.c:3920 [inline]
 rtnetlink_event+0x155/0x1b0 net/core/rtnetlink.c:5698
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391
 call_netdevice_notifiers_info net/core/dev.c:2018 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2030 [inline]
 call_netdevice_notifiers net/core/dev.c:2044 [inline]
 dev_set_mac_address+0x325/0x470 net/core/dev.c:9082
 dev_set_mac_address_user+0x2d/0x50 net/core/dev.c:9096
 do_setlink+0x7f0/0x3d80 net/core/rtnetlink.c:2731
 __rtnl_newlink net/core/rtnetlink.c:3447 [inline]
 rtnl_newlink+0x17d6/0x2070 net/core/rtnetlink.c:3569
 rtnetlink_rcv_msg+0x993/0xee0 net/core/rtnetlink.c:5647
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396
 do_slab_free mm/slub.c:3487 [inline]
 ___cache_free+0xe3/0x100 mm/slub.c:3506
 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc_trace+0xfb/0x290 mm/slub.c:3245
 kmalloc include/linux/slab.h:591 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 nsim_fib6_rt_create drivers/net/netdevsim/fib.c:545 [inline]
 nsim_fib6_rt_insert drivers/net/netdevsim/fib.c:750 [inline]
 nsim_fib6_event drivers/net/netdevsim/fib.c:854 [inline]
 nsim_fib_event drivers/net/netdevsim/fib.c:887 [inline]
 nsim_fib_event_work+0x19be/0x4120 drivers/net/netdevsim/fib.c:1483
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 process_scheduled_works kernel/workqueue.c:2373 [inline]
 worker_thread+0xdcf/0x1280 kernel/workqueue.c:2459
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
 ffff8880756a0380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880756a0400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880756a0480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff8880756a0500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880756a0580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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