================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: slab-use-after-free in atomic_long_read include/linux/atomic/atomic-instrumented.h:3188 [inline] BUG: KASAN: slab-use-after-free in __mutex_unlock_slowpath+0xd4/0x700 kernel/locking/mutex.c:918 Read of size 8 at addr ffff8880585bbad0 by task kworker/0:19/7501 CPU: 0 UID: 0 PID: 7501 Comm: kworker/0:19 Not tainted 6.16.0-rc4-syzkaller-00991-g6b9fd8857b9f #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events l2cap_chan_timeout Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_long_read include/linux/atomic/atomic-instrumented.h:3188 [inline] __mutex_unlock_slowpath+0xd4/0x700 kernel/locking/mutex.c:918 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 10940: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] l2cap_conn_add+0xaa/0x8d0 net/bluetooth/l2cap_core.c:6870 l2cap_chan_connect+0x6c8/0xe30 net/bluetooth/l2cap_core.c:7061 l2cap_sock_connect+0x5c8/0x7a0 net/bluetooth/l2cap_sock.c:256 kernel_connect+0x113/0x180 net/socket.c:3656 rfcomm_session_create net/bluetooth/rfcomm/core.c:811 [inline] __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:388 [inline] rfcomm_dlc_open+0x8fe/0xed0 net/bluetooth/rfcomm/core.c:431 rfcomm_sock_connect+0x2f7/0x610 net/bluetooth/rfcomm/sock.c:409 __sys_connect_file net/socket.c:2086 [inline] __sys_connect+0x313/0x440 net/socket.c:2105 __do_sys_connect net/socket.c:2111 [inline] __se_sys_connect net/socket.c:2108 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2108 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 10739: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 hci_disconn_cfm include/net/bluetooth/hci_core.h:2071 [inline] hci_conn_hash_flush+0x10a/0x230 net/bluetooth/hci_conn.c:2560 hci_dev_close_sync+0xaef/0x1330 net/bluetooth/hci_sync.c:5294 hci_dev_do_close net/bluetooth/hci_core.c:501 [inline] hci_unregister_dev+0x21a/0x510 net/bluetooth/hci_core.c:2717 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:665 __fput+0x449/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x22e0 kernel/exit.c:964 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105 __do_sys_exit_group kernel/exit.c:1116 [inline] __se_sys_exit_group kernel/exit.c:1114 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1114 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880585bb800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 720 bytes inside of freed 1024-byte region [ffff8880585bb800, ffff8880585bbc00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880585ba000 pfn:0x585b8 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 ffff88801a441dc0 ffffea0000d4fe10 ffffea0000a5ca10 raw: ffff8880585ba000 000000000010000d 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801a441dc0 ffffea0000d4fe10 ffffea0000a5ca10 head: ffff8880585ba000 000000000010000d 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001616e01 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 9029, tgid 9025 (syz.0.774), ts 221318306752, free_ts 221131676995 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2619 new_slab mm/slub.c:2673 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859 __slab_alloc mm/slub.c:3949 [inline] __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_track_caller_noprof+0x2f8/0x4e0 mm/slub.c:4347 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] xfrm_alloc_compat+0x1a6/0x16f0 net/xfrm/xfrm_compat.c:348 xfrm_nlmsg_multicast+0xd7/0x1f0 net/xfrm/xfrm_user.c:1580 xfrm_send_acquire+0x99d/0xee0 net/xfrm/xfrm_user.c:3842 km_query+0x11c/0x210 net/xfrm/xfrm_state.c:2762 xfrm_state_find+0x3c07/0x5450 net/xfrm/xfrm_state.c:1572 xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:2522 [inline] xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:2573 [inline] xfrm_resolve_and_create_bundle+0x768/0x2f90 net/xfrm/xfrm_policy.c:2871 xfrm_lookup_with_ifid+0x2a7/0x1a70 net/xfrm/xfrm_policy.c:3205 page last free pid 9029 tgid 9025 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 __slab_free+0x326/0x400 mm/slub.c:4554 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4249 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1336 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6665 sock_alloc_send_pskb+0x857/0x990 net/core/sock.c:2974 sock_alloc_send_skb include/net/sock.h:1847 [inline] __ip_append_data+0x2cff/0x40d0 net/ipv4/ip_output.c:1120 ip_make_skb+0x1de/0x3f0 net/ipv4/ip_output.c:1568 udp_sendmsg+0x1925/0x2300 net/ipv4/udp.c:1479 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x19c/0x270 net/socket.c:729 ____sys_sendmsg+0x52d/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmmsg+0x227/0x430 net/socket.c:2757 Memory state around the buggy address: ffff8880585bb980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880585bba00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880585bba80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880585bbb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880585bbb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================