================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_ready_cb+0x16a/0x170 net/bluetooth/l2cap_sock.c:1684 Read of size 8 at addr ffff888050094188 by task kworker/u33:0/67 CPU: 3 UID: 0 PID: 67 Comm: kworker/u33:0 Not tainted 6.15.0-rc1-syzkaller-00173-g0c7cae12f67c #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: hci0 hci_rx_work 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:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 l2cap_sock_ready_cb+0x16a/0x170 net/bluetooth/l2cap_sock.c:1684 l2cap_chan_ready net/bluetooth/l2cap_core.c:1246 [inline] l2cap_le_start+0x1ea/0xe40 net/bluetooth/l2cap_core.c:1375 l2cap_conn_ready net/bluetooth/l2cap_core.c:1627 [inline] l2cap_connect_cfm+0x8f4/0xf80 net/bluetooth/l2cap_core.c:7278 hci_connect_cfm include/net/bluetooth/hci_core.h:2054 [inline] le_conn_complete_evt+0x1662/0x1d70 net/bluetooth/hci_event.c:5779 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5805 hci_le_meta_evt+0x2f3/0x5e0 net/bluetooth/hci_event.c:7181 hci_event_func net/bluetooth/hci_event.c:7489 [inline] hci_event_packet+0x669/0x1190 net/bluetooth/hci_event.c:7544 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4020 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 7238: 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:260 [inline] __do_kmalloc_node mm/slub.c:4331 [inline] __kmalloc_noprof+0x223/0x510 mm/slub.c:4343 kmalloc_noprof include/linux/slab.h:909 [inline] sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2198 sk_alloc+0x36/0xc20 net/core/sock.c:2254 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc.constprop.0+0x33/0x1d0 net/bluetooth/l2cap_sock.c:1891 l2cap_sock_create+0x123/0x1f0 net/bluetooth/l2cap_sock.c:1933 bt_sock_create+0x182/0x350 net/bluetooth/af_bluetooth.c:132 __sock_create+0x335/0x8d0 net/socket.c:1541 sock_create net/socket.c:1599 [inline] __sys_socket_create net/socket.c:1636 [inline] __sys_socket+0x14d/0x260 net/socket.c:1683 __do_sys_socket net/socket.c:1697 [inline] __se_sys_socket net/socket.c:1695 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1695 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 7238: 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:576 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:2389 [inline] slab_free mm/slub.c:4646 [inline] kfree+0x2b6/0x4d0 mm/slub.c:4845 sk_prot_free net/core/sock.c:2237 [inline] __sk_destruct+0x740/0x980 net/core/sock.c:2332 sk_destruct+0xc2/0xf0 net/core/sock.c:2360 __sk_free+0xf4/0x3e0 net/core/sock.c:2371 sk_free+0x6a/0x90 net/core/sock.c:2382 sock_put include/net/sock.h:1944 [inline] l2cap_sock_kill net/bluetooth/l2cap_sock.c:1265 [inline] l2cap_sock_kill+0x171/0x2d0 net/bluetooth/l2cap_sock.c:1250 l2cap_sock_release+0x189/0x210 net/bluetooth/l2cap_sock.c:1435 __sock_release+0xb0/0x270 net/socket.c:647 sock_close+0x1c/0x30 net/socket.c:1391 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x14d/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [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+0x27b/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888050094000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 392 bytes inside of freed 2048-byte region [ffff888050094000, ffff888050094800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x50090 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b442f00 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b442f00 0000000000000000 dead000000000001 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001402401 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 5939, tgid 5939 (syz-executor), ts 48018983643, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1717 prep_new_page mm/page_alloc.c:1725 [inline] get_page_from_freelist+0x1193/0x39b0 mm/page_alloc.c:3652 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4934 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2459 [inline] allocate_slab mm/slub.c:2623 [inline] new_slab+0x23c/0x330 mm/slub.c:2676 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3862 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3952 __slab_alloc_node mm/slub.c:4027 [inline] slab_alloc_node mm/slub.c:4188 [inline] __do_kmalloc_node mm/slub.c:4330 [inline] __kmalloc_node_noprof+0x2ed/0x500 mm/slub.c:4337 kmalloc_node_noprof include/linux/slab.h:932 [inline] qdisc_alloc+0xbb/0xc50 net/sched/sch_generic.c:947 qdisc_create_dflt+0x73/0x430 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:2650 [inline] attach_default_qdiscs net/sched/sch_generic.c:1193 [inline] dev_activate+0x63f/0x12d0 net/sched/sch_generic.c:1252 __dev_open+0x43a/0x7d0 net/core/dev.c:1636 __dev_change_flags+0x55d/0x720 net/core/dev.c:9364 netif_change_flags+0x8d/0x160 net/core/dev.c:9427 do_setlink.constprop.0+0xddf/0x44b0 net/core/rtnetlink.c:3152 rtnl_changelink net/core/rtnetlink.c:3772 [inline] __rtnl_newlink net/core/rtnetlink.c:3931 [inline] rtnl_newlink+0x1446/0x2000 net/core/rtnetlink.c:4068 page_owner free stack trace missing Memory state around the buggy address: ffff888050094080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050094100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888050094180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888050094200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050094280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================