================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_ready_cb+0x16a/0x170 net/bluetooth/l2cap_sock.c:1672 Read of size 8 at addr ffff88804ddc2188 by task kworker/u33:6/5951 CPU: 1 UID: 0 PID: 5951 Comm: kworker/u33:6 Not tainted 6.14.0-rc2-syzkaller-00039-g09fbf3d50205 #0 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:378 [inline] print_report+0xc3/0x620 mm/kasan/report.c:489 kasan_report+0xd9/0x110 mm/kasan/report.c:602 l2cap_sock_ready_cb+0x16a/0x170 net/bluetooth/l2cap_sock.c:1672 l2cap_chan_ready net/bluetooth/l2cap_core.c:1239 [inline] l2cap_le_start+0x1ec/0xe40 net/bluetooth/l2cap_core.c:1368 l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline] l2cap_connect_cfm+0x99f/0xf10 net/bluetooth/l2cap_core.c:7280 hci_connect_cfm include/net/bluetooth/hci_core.h:2051 [inline] le_conn_complete_evt+0x168d/0x1da0 net/bluetooth/hci_event.c:5763 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5789 hci_le_meta_evt+0x2e2/0x5d0 net/bluetooth/hci_event.c:7162 hci_event_func net/bluetooth/hci_event.c:7470 [inline] hci_event_packet+0x666/0x1180 net/bluetooth/hci_event.c:7525 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4015 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 3869: 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:4294 [inline] __kmalloc_noprof+0x21c/0x510 mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2181 sk_alloc+0x36/0xb90 net/core/sock.c:2234 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc.constprop.0+0x33/0x1d0 net/bluetooth/l2cap_sock.c:1879 l2cap_sock_create+0x123/0x1f0 net/bluetooth/l2cap_sock.c:1921 bt_sock_create+0x182/0x350 net/bluetooth/af_bluetooth.c:132 __sock_create+0x335/0x8d0 net/socket.c:1548 sock_create net/socket.c:1606 [inline] __sys_socket_create net/socket.c:1643 [inline] __sys_socket+0x14f/0x260 net/socket.c:1690 __do_sys_socket net/socket.c:1704 [inline] __se_sys_socket net/socket.c:1702 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1702 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 Freed by task 3869: 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:2353 [inline] slab_free mm/slub.c:4609 [inline] kfree+0x2c4/0x4d0 mm/slub.c:4757 sk_prot_free net/core/sock.c:2217 [inline] __sk_destruct+0x5eb/0x720 net/core/sock.c:2309 sk_destruct+0xc2/0xf0 net/core/sock.c:2324 __sk_free+0xf4/0x3e0 net/core/sock.c:2335 sk_free+0x6a/0x90 net/core/sock.c:2346 sock_put include/net/sock.h:1913 [inline] l2cap_sock_kill net/bluetooth/l2cap_sock.c:1252 [inline] l2cap_sock_kill+0x171/0x2d0 net/bluetooth/l2cap_sock.c:1237 l2cap_sock_release+0x189/0x210 net/bluetooth/l2cap_sock.c:1423 __sock_release+0xb0/0x270 net/socket.c:647 sock_close+0x1c/0x30 net/socket.c:1398 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 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/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88804ddc2000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 392 bytes inside of freed 2048-byte region [ffff88804ddc2000, ffff88804ddc2800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4ddc0 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 ffff88801b042f00 ffffea000142bc00 dead000000000002 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b042f00 ffffea000142bc00 dead000000000002 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001377001 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 5936, tgid 5936 (syz-executor), ts 46063396700, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739 alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab mm/slub.c:2587 [inline] new_slab+0x23d/0x330 mm/slub.c:2640 ___slab_alloc+0xc5d/0x1720 mm/slub.c:3826 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] __kmalloc_cache_noprof+0xfa/0x410 mm/slub.c:4320 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] rxrpc_alloc_connection+0x8b/0x740 net/rxrpc/conn_object.c:62 rxrpc_prealloc_service_connection+0x26/0x380 net/rxrpc/conn_service.c:123 rxrpc_service_prealloc_one+0x2bf/0xef0 net/rxrpc/call_accept.c:87 rxrpc_kernel_charge_accept+0xd7/0x120 net/rxrpc/call_accept.c:475 afs_charge_preallocation+0xce/0x330 fs/afs/rxrpc.c:739 afs_open_socket+0x2b3/0x380 fs/afs/rxrpc.c:95 afs_net_init+0x95d/0xc60 fs/afs/main.c:123 ops_init+0x1df/0x5f0 net/core/net_namespace.c:138 page_owner free stack trace missing Memory state around the buggy address: ffff88804ddc2080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804ddc2100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804ddc2180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804ddc2200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804ddc2280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================