================================================================== BUG: KASAN: slab-use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1639 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0xde7/0xf80 net/bluetooth/l2cap_core.c:7414 Read of size 8 at addr ffff888012a0e480 by task kworker/u33:7/5950 CPU: 3 UID: 0 PID: 5950 Comm: kworker/u33:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: hci0 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595 l2cap_conn_ready net/bluetooth/l2cap_core.c:1639 [inline] l2cap_connect_cfm+0xde7/0xf80 net/bluetooth/l2cap_core.c:7414 hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline] le_conn_complete_evt+0x197c/0x1f60 net/bluetooth/hci_event.c:5858 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5884 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7499 hci_event_func net/bluetooth/hci_event.c:7763 [inline] hci_event_packet+0x51c/0xcd0 net/bluetooth/hci_event.c:7817 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5950: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] l2cap_chan_create+0x44/0x940 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc.constprop.0+0xf5/0x1e0 net/bluetooth/l2cap_sock.c:1934 l2cap_sock_new_connection_cb+0x101/0x260 net/bluetooth/l2cap_sock.c:1510 l2cap_connect_cfm+0x4e2/0xf80 net/bluetooth/l2cap_core.c:7397 hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline] le_conn_complete_evt+0x197c/0x1f60 net/bluetooth/hci_event.c:5858 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5884 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7499 hci_event_func net/bluetooth/hci_event.c:7763 [inline] hci_event_packet+0x51c/0xcd0 net/bluetooth/hci_event.c:7817 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 6616: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6165 [inline] kfree+0x1f6/0x6b0 mm/slub.c:6483 l2cap_chan_destroy net/bluetooth/l2cap_core.c:491 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_chan_put+0x235/0x300 net/bluetooth/l2cap_core.c:516 l2cap_sock_cleanup_listen+0x4d/0x2d0 net/bluetooth/l2cap_sock.c:1493 l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1451 __sock_release+0xb3/0x260 net/socket.c:662 sock_close+0x1c/0x30 net/socket.c:1455 __fput+0x3ff/0xb40 fs/file_table.c:469 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x100/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] __do_fast_syscall_32+0x578/0x8c0 arch/x86/entry/syscall_32.c:310 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff888012a0e000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff888012a0e000, ffff888012a0e800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888012a0b000 pfn:0x12a08 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 ffff88801b842f00 ffffea000086b010 ffffea000086d810 raw: ffff888012a0b000 0000000800080007 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b842f00 ffffea000086b010 ffffea000086d810 head: ffff888012a0b000 0000000800080007 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea00004a8201 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5936, tgid 5936 (syz-executor), ts 54731995396, free_ts 34151068888 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab mm/slub.c:3481 [inline] new_slab+0xa6/0x6b0 mm/slub.c:3539 refill_objects+0x26b/0x400 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] __do_kmalloc_node mm/slub.c:5259 [inline] __kmalloc_node_track_caller_noprof+0x694/0x850 mm/slub.c:5368 kmalloc_reserve+0xe8/0x350 net/core/skbuff.c:635 pskb_expand_head+0x246/0xfe0 net/core/skbuff.c:2315 netlink_trim+0x22d/0x2f0 net/netlink/af_netlink.c:1299 netlink_broadcast_filtered+0xd7/0xf50 net/netlink/af_netlink.c:1512 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0xb1/0x290 net/netlink/af_netlink.c:2593 rtnl_notify net/core/rtnetlink.c:964 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:4458 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4474 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4461 [inline] rtnetlink_event+0x1b3/0x1f0 net/core/rtnetlink.c:7040 notifier_call_chain+0x99/0x420 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] netif_change_name+0x4d9/0x830 net/core/dev.c:1509 page last free pid 44 tgid 44 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978 __folio_put+0x3b4/0x540 mm/swap.c:112 folio_put include/linux/mm.h:1817 [inline] migrate_folio_done+0x2a1/0x360 mm/migrate.c:1199 migrate_folio_move mm/migrate.c:1413 [inline] migrate_folios_move mm/migrate.c:1721 [inline] migrate_pages_batch+0x1a90/0x4530 mm/migrate.c:1977 migrate_pages_sync+0x12c/0x880 mm/migrate.c:2007 migrate_pages+0x1aae/0x28a0 mm/migrate.c:2116 compact_zone+0x2464/0x44c0 mm/compaction.c:2647 compact_node+0x17f/0x2c0 mm/compaction.c:2916 kcompactd+0x74f/0xe00 mm/compaction.c:3214 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888012a0e380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888012a0e400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888012a0e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888012a0e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888012a0e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================