================================================================== BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:174 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:666 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0x813/0x1000 kernel/locking/mutex.c:732 Read of size 8 at addr ffff88807f619b20 by task kworker/1:2/978 CPU: 1 UID: 0 PID: 978 Comm: kworker/1:2 Not tainted 6.14.0-syzkaller-05884-g2ea396448f26 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events l2cap_chan_timeout Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0x16e/0x5b0 mm/kasan/report.c:521 kasan_report+0x143/0x180 mm/kasan/report.c:634 __mutex_waiter_is_first kernel/locking/mutex.c:174 [inline] __mutex_lock_common kernel/locking/mutex.c:666 [inline] __mutex_lock+0x813/0x1000 kernel/locking/mutex.c:732 l2cap_chan_timeout+0x63/0x360 net/bluetooth/l2cap_core.c:417 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 10361: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x9d/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x236/0x370 mm/slub.c:4349 kmalloc_noprof include/linux/slab.h:902 [inline] kzalloc_noprof include/linux/slab.h:1036 [inline] l2cap_conn_add+0xa9/0x8e0 net/bluetooth/l2cap_core.c:6860 l2cap_chan_connect+0x627/0xea0 net/bluetooth/l2cap_core.c:7051 l2cap_sock_connect+0x622/0x950 net/bluetooth/l2cap_sock.c:256 kernel_connect+0x11b/0x190 net/socket.c:3608 rfcomm_session_create net/bluetooth/rfcomm/core.c:811 [inline] __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:388 [inline] rfcomm_dlc_open+0xad9/0x10d0 net/bluetooth/rfcomm/core.c:431 rfcomm_sock_connect+0x305/0x610 net/bluetooth/rfcomm/sock.c:409 __sys_connect_file net/socket.c:2038 [inline] __sys_connect+0x28c/0x2d0 net/socket.c:2057 __do_sys_connect net/socket.c:2063 [inline] __se_sys_connect net/socket.c:2060 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2060 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 10173: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2376 [inline] slab_free mm/slub.c:4633 [inline] kfree+0x198/0x430 mm/slub.c:4832 hci_disconn_cfm include/net/bluetooth/hci_core.h:2069 [inline] hci_conn_hash_flush+0xff/0x240 net/bluetooth/hci_conn.c:2701 hci_dev_close_sync+0xa8d/0x1260 net/bluetooth/hci_sync.c:5225 hci_dev_do_close net/bluetooth/hci_core.c:483 [inline] hci_unregister_dev+0x20b/0x510 net/bluetooth/hci_core.c:2678 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:665 __fput+0x3e9/0x9f0 fs/file_table.c:465 task_work_run+0x251/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2a/0x2940 kernel/exit.c:954 do_group_exit+0x207/0x2c0 kernel/exit.c:1103 __do_sys_exit_group kernel/exit.c:1114 [inline] __se_sys_exit_group kernel/exit.c:1112 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1112 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807f619800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 800 bytes inside of freed 1024-byte region [ffff88807f619800, ffff88807f619c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7f618 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 ffff88801b041dc0 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b041dc0 0000000000000000 dead000000000001 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001fd8601 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5907, tgid 5907 (kworker/1:9), ts 173879156390, free_ts 173814500084 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0x3695/0x37e0 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x2c5/0x7b0 mm/page_alloc.c:4740 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2446 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2610 new_slab mm/slub.c:2663 [inline] ___slab_alloc+0xc3b/0x1500 mm/slub.c:3849 __slab_alloc+0x58/0xa0 mm/slub.c:3939 __slab_alloc_node mm/slub.c:4014 [inline] slab_alloc_node mm/slub.c:4175 [inline] __do_kmalloc_node mm/slub.c:4317 [inline] __kmalloc_noprof+0x2ea/0x4d0 mm/slub.c:4330 kmalloc_noprof include/linux/slab.h:906 [inline] kzalloc_noprof include/linux/slab.h:1036 [inline] neigh_alloc net/core/neighbour.c:473 [inline] ___neigh_create+0x6c3/0x2360 net/core/neighbour.c:607 ip6_finish_output2+0xb31/0x1750 net/ipv6/ip6_output.c:132 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x421/0x840 net/ipv6/ip6_output.c:226 NF_HOOK+0xa0/0x440 include/linux/netfilter.h:314 mld_sendpack+0x84a/0xdc0 net/ipv6/mcast.c:1868 mld_send_cr net/ipv6/mcast.c:2169 [inline] mld_ifc_work+0x7d9/0xd90 net/ipv6/mcast.c:2702 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 page last free pid 10355 tgid 10354 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe16/0x10f0 mm/page_alloc.c:2660 __slab_free+0x2c6/0x390 mm/slub.c:4544 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4138 [inline] slab_alloc_node mm/slub.c:4187 [inline] __kmalloc_cache_noprof+0x1c8/0x370 mm/slub.c:4344 kmalloc_noprof include/linux/slab.h:902 [inline] kzalloc_noprof include/linux/slab.h:1036 [inline] sctp_stream_init_ext+0x56/0x180 net/sctp/stream.c:169 sctp_sendmsg_to_asoc+0x132c/0x1870 net/sctp/socket.c:1810 sctp_sendmsg+0x2512/0x3620 net/sctp/socket.c:2031 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:727 ____sys_sendmsg+0x523/0x860 net/socket.c:2566 ___sys_sendmsg net/socket.c:2620 [inline] __sys_sendmmsg+0x3a0/0x7b0 net/socket.c:2709 __do_sys_sendmmsg net/socket.c:2736 [inline] __se_sys_sendmmsg net/socket.c:2733 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2733 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807f619a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807f619a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807f619b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807f619b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807f619c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================