================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x24c/0x260 net/bluetooth/l2cap_sock.c:1528 Read of size 8 at addr ffff88805732b5a8 by task kworker/u33:2/5741 CPU: 2 UID: 0 PID: 5741 Comm: kworker/u33:2 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: hci3 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+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595 l2cap_sock_new_connection_cb+0x24c/0x260 net/bluetooth/l2cap_sock.c:1528 l2cap_connect_cfm+0x4e2/0xf80 net/bluetooth/l2cap_core.c:7402 hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline] le_conn_complete_evt+0x197c/0x1f60 net/bluetooth/hci_event.c:5865 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5891 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7529 hci_event_func net/bluetooth/hci_event.c:7793 [inline] hci_event_packet+0x51c/0xcd0 net/bluetooth/hci_event.c:7847 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5741: 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 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_noprof+0x301/0x850 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] sk_prot_alloc+0x10b/0x2a0 net/core/sock.c:2247 sk_alloc+0x36/0xe80 net/core/sock.c:2303 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc.constprop.0+0x33/0x1e0 net/bluetooth/l2cap_sock.c:1934 l2cap_sock_new_connection_cb+0x10f/0x260 net/bluetooth/l2cap_sock.c:1513 l2cap_connect_cfm+0x4e2/0xf80 net/bluetooth/l2cap_core.c:7402 hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline] le_conn_complete_evt+0x197c/0x1f60 net/bluetooth/hci_event.c:5865 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5891 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7529 hci_event_func net/bluetooth/hci_event.c:7793 [inline] hci_event_packet+0x51c/0xcd0 net/bluetooth/hci_event.c:7847 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 14485: 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:2689 [inline] slab_free mm/slub.c:6250 [inline] kfree+0x223/0x6c0 mm/slub.c:6565 sk_prot_free net/core/sock.c:2286 [inline] __sk_destruct+0x88c/0xab0 net/core/sock.c:2386 sk_destruct+0xc8/0xf0 net/core/sock.c:2414 __sk_free+0xf4/0x3e0 net/core/sock.c:2425 sk_free+0x61/0x90 net/core/sock.c:2436 sock_put include/net/sock.h:2010 [inline] l2cap_sock_kill net/bluetooth/l2cap_sock.c:1290 [inline] l2cap_sock_kill+0x176/0x310 net/bluetooth/l2cap_sock.c:1275 l2cap_sock_cleanup_listen+0x3d/0x2d0 net/bluetooth/l2cap_sock.c:1490 l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1451 __sock_release+0xb3/0x260 net/socket.c:722 sock_close+0x1c/0x30 net/socket.c:1514 __fput+0x3ff/0xb50 fs/file_table.c:510 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+0x107/0x4f0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x706/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805732b000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1448 bytes inside of freed 2048-byte region [ffff88805732b000, ffff88805732b800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x57328 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 ffff88801b842f00 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842f00 dead000000000100 dead000000000122 head: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 00fff00000000003 fffffffffffffe01 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 5736, tgid 5736 (syz-executor), ts 64261818243, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x11a6/0x33b0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab mm/slub.c:3467 [inline] new_slab+0xa6/0x6c0 mm/slub.c:3525 refill_objects+0x277/0x420 mm/slub.c:7271 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __do_kmalloc_node mm/slub.c:5294 [inline] __kmalloc_noprof+0x688/0x850 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] sk_prot_alloc+0x10b/0x2a0 net/core/sock.c:2247 sk_alloc+0x36/0xe80 net/core/sock.c:2303 __netlink_create+0x5e/0x2c0 net/netlink/af_netlink.c:626 netlink_create+0x29b/0x610 net/netlink/af_netlink.c:684 __sock_create+0x339/0x860 net/socket.c:1664 sock_create net/socket.c:1722 [inline] __sys_socket_create net/socket.c:1759 [inline] __sys_socket+0x14d/0x260 net/socket.c:1806 __do_sys_socket net/socket.c:1820 [inline] __se_sys_socket net/socket.c:1818 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1818 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page_owner free stack trace missing Memory state around the buggy address: ffff88805732b480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805732b500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805732b580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805732b600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805732b680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================