================================================================== BUG: KASAN: slab-use-after-free in hci_send_acl+0xeb7/0x1050 net/bluetooth/hci_core.c:3231 Read of size 8 at addr ffff8880612eca18 by task kworker/3:4/5207 CPU: 3 PID: 5207 Comm: kworker/3:4 Not tainted 6.6.0-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Workqueue: events l2cap_info_timeout Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 hci_send_acl+0xeb7/0x1050 net/bluetooth/hci_core.c:3231 l2cap_send_cmd+0x6dd/0x920 net/bluetooth/l2cap_core.c:977 l2cap_send_conn_req+0x1e5/0x260 net/bluetooth/l2cap_core.c:1286 l2cap_start_connection+0x11e/0x420 net/bluetooth/l2cap_core.c:1514 l2cap_conn_start+0x7ae/0xa40 net/bluetooth/l2cap_core.c:1661 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Allocated by task 19851: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] hci_chan_create+0xa6/0x3d0 net/bluetooth/hci_conn.c:2723 l2cap_conn_add.part.0+0x1a/0xdf0 net/bluetooth/l2cap_core.c:7841 l2cap_conn_add include/net/bluetooth/hci_core.h:1521 [inline] l2cap_chan_connect+0x15de/0x2170 net/bluetooth/l2cap_core.c:8053 bt_6lowpan_connect net/bluetooth/6lowpan.c:894 [inline] lowpan_control_write+0x3d6/0x730 net/bluetooth/6lowpan.c:1129 full_proxy_write+0x124/0x190 fs/debugfs/file.c:236 vfs_write+0x2a4/0xe40 fs/read_write.c:582 ksys_write+0x12f/0x250 fs/read_write.c:637 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Freed by task 62: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3822 hci_chan_list_flush+0x81/0xf0 net/bluetooth/hci_conn.c:2763 hci_conn_cleanup net/bluetooth/hci_conn.c:152 [inline] hci_conn_del+0x201/0xd80 net/bluetooth/hci_conn.c:1156 hci_abort_conn_sync+0x573/0xe10 net/bluetooth/hci_sync.c:5428 abort_conn_sync+0x187/0x390 net/bluetooth/hci_conn.c:2910 hci_cmd_sync_work+0x1a4/0x410 net/bluetooth/hci_sync.c:306 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492 kvfree_call_rcu+0x70/0xbe0 kernel/rcu/tree.c:3372 kernfs_unlink_open_file+0x3b6/0x4b0 fs/kernfs/file.c:633 kernfs_fop_release+0xec/0x1e0 fs/kernfs/file.c:805 __fput+0x3f7/0xa70 fs/file_table.c:384 __fput_sync+0x47/0x50 fs/file_table.c:465 __do_sys_close fs/open.c:1572 [inline] __se_sys_close fs/open.c:1557 [inline] __x64_sys_close+0x87/0xf0 fs/open.c:1557 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492 kvfree_call_rcu+0x70/0xbe0 kernel/rcu/tree.c:3372 kernfs_unlink_open_file+0x3b6/0x4b0 fs/kernfs/file.c:633 kernfs_fop_release+0xec/0x1e0 fs/kernfs/file.c:805 __fput+0x3f7/0xa70 fs/file_table.c:384 __fput_sync+0x47/0x50 fs/file_table.c:465 __do_sys_close fs/open.c:1572 [inline] __se_sys_close fs/open.c:1557 [inline] __x64_sys_close+0x87/0xf0 fs/open.c:1557 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff8880612eca00 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 24 bytes inside of freed 128-byte region [ffff8880612eca00, ffff8880612eca80) The buggy address belongs to the physical page: page:ffffea000184bb00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880612ec800 pfn:0x612ec flags: 0x4fff00000000800(slab|node=1|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 04fff00000000800 ffff888012c428c0 ffffea000184bc50 ffffea00018a4410 raw: ffff8880612ec800 0000000000100006 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 5161, tgid 5161 (syz-executor.2), ts 52955962301, free_ts 52955915278 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426 __alloc_pages_node include/linux/gfp.h:237 [inline] alloc_slab_page mm/slub.c:1872 [inline] allocate_slab+0xa1/0x380 mm/slub.c:2017 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8c7/0x1580 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x131/0x340 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1025 [inline] __kmalloc_node+0x52/0x110 mm/slab_common.c:1033 kmalloc_array_node include/linux/slab.h:697 [inline] kcalloc_node include/linux/slab.h:702 [inline] memcg_alloc_slab_cgroups+0xa9/0x170 mm/memcontrol.c:2895 memcg_slab_post_alloc_hook+0xaa/0x390 mm/slab.h:530 slab_post_alloc_hook mm/slab.h:770 [inline] slab_alloc_node mm/slub.c:3478 [inline] __kmem_cache_alloc_node+0x1cb/0x340 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1025 [inline] __kmalloc_node+0x52/0x110 mm/slab_common.c:1033 kmalloc_node include/linux/slab.h:619 [inline] kvmalloc_node+0x99/0x1a0 mm/util.c:607 kvmalloc include/linux/slab.h:737 [inline] xt_alloc_table_info+0x3e/0xa0 net/netfilter/x_tables.c:1192 compat_do_replace.constprop.0+0x1a2/0x4b0 net/ipv6/netfilter/ip6_tables.c:1515 do_ip6t_set_ctl+0x5e4/0xbc0 net/ipv6/netfilter/ip6_tables.c:1633 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1136 [inline] free_unref_page_prepare+0x476/0xa40 mm/page_alloc.c:2312 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2405 vfree+0x181/0x7a0 mm/vmalloc.c:2842 xt_compat_flush_offsets+0x8f/0x160 net/netfilter/x_tables.c:691 compat_get_entries+0x234/0x850 net/ipv6/netfilter/ip6_tables.c:1610 do_ip6t_get_ctl+0x569/0xab0 net/ipv6/netfilter/ip6_tables.c:1666 nf_getsockopt+0x76/0xe0 net/netfilter/nf_sockopt.c:116 ipv6_getsockopt+0x1f9/0x2b0 net/ipv6/ipv6_sockglue.c:1500 tcp_getsockopt+0x97/0xf0 net/ipv4/tcp.c:4280 __sys_getsockopt+0x220/0x6a0 net/socket.c:2371 __do_compat_sys_socketcall+0x428/0x700 net/compat.c:494 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Memory state around the buggy address: ffff8880612ec900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880612ec980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880612eca00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880612eca80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880612ecb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================