================================================================== BUG: KASAN: use-after-free in hci_chan_del+0x40/0x1bc net/bluetooth/hci_conn.c:2780 Read of size 8 at addr ffff0000f244fe18 by task syz-executor/4337 CPU: 0 PID: 4337 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 print_address_description+0x88/0x218 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:420 kasan_report+0xa8/0xfc mm/kasan/report.c:524 __asan_report_load8_noabort+0x2c/0x38 mm/kasan/report_generic.c:351 hci_chan_del+0x40/0x1bc net/bluetooth/hci_conn.c:2780 l2cap_conn_free net/bluetooth/l2cap_core.c:1868 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put+0x80/0x10c net/bluetooth/l2cap_core.c:1882 l2cap_chan_destroy net/bluetooth/l2cap_core.c:502 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_chan_put+0x194/0x26c net/bluetooth/l2cap_core.c:529 l2cap_sock_release+0x160/0x1c8 net/bluetooth/l2cap_sock.c:1494 __sock_release net/socket.c:654 [inline] sock_close+0xac/0x1ec net/socket.c:1400 __fput+0x1b4/0x7b0 fs/file_table.c:320 ____fput+0x20/0x30 fs/file_table.c:348 task_work_run+0x1f4/0x280 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x54c/0x19ac kernel/exit.c:887 do_group_exit+0x198/0x238 kernel/exit.c:1030 __do_sys_exit_group kernel/exit.c:1041 [inline] __se_sys_exit_group kernel/exit.c:1039 [inline] __wake_up_parent+0x0/0x60 kernel/exit.c:1039 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:589 Allocated by task 4335: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0xa0/0xb8 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace+0x7c/0x94 mm/slab_common.c:1031 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] hci_chan_create+0xa8/0x2ac net/bluetooth/hci_conn.c:2765 l2cap_conn_add+0x78/0x764 net/bluetooth/l2cap_core.c:7211 l2cap_connect_cfm+0x124/0xedc net/bluetooth/l2cap_core.c:7598 hci_connect_cfm include/net/bluetooth/hci_core.h:1822 [inline] hci_remote_features_evt+0x46c/0x840 net/bluetooth/hci_event.c:3756 hci_event_func net/bluetooth/hci_event.c:7304 [inline] hci_event_packet+0x4f0/0xb30 net/bluetooth/hci_event.c:7353 hci_rx_work+0x310/0xa70 net/bluetooth/hci_core.c:4041 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439 kthread+0x254/0x2e0 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854 Freed by task 4337: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:237 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:245 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1735 [inline] slab_free_freelist_hook+0x16c/0x1e8 mm/slub.c:1761 slab_free mm/slub.c:3694 [inline] __kmem_cache_free+0xbc/0x21c mm/slub.c:3707 kfree+0xd0/0x1a8 mm/slab_common.c:988 hci_chan_del+0x148/0x1bc net/bluetooth/hci_conn.c:2795 hci_chan_list_flush net/bluetooth/hci_conn.c:2805 [inline] hci_conn_cleanup+0x12c/0x6ac net/bluetooth/hci_conn.c:149 hci_conn_del+0x308/0x560 net/bluetooth/hci_conn.c:1234 hci_conn_hash_flush+0x1d8/0x26c net/bluetooth/hci_conn.c:2610 hci_dev_close_sync+0x848/0x10b4 net/bluetooth/hci_sync.c:5328 hci_dev_do_close net/bluetooth/hci_core.c:523 [inline] hci_unregister_dev+0x20c/0x4d8 net/bluetooth/hci_core.c:2720 vhci_release+0x7c/0xcc drivers/bluetooth/hci_vhci.c:565 __fput+0x1b4/0x7b0 fs/file_table.c:320 ____fput+0x20/0x30 fs/file_table.c:348 task_work_run+0x1f4/0x280 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x54c/0x19ac kernel/exit.c:887 do_group_exit+0x198/0x238 kernel/exit.c:1030 __do_sys_exit_group kernel/exit.c:1041 [inline] __se_sys_exit_group kernel/exit.c:1039 [inline] __wake_up_parent+0x0/0x60 kernel/exit.c:1039 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:589 The buggy address belongs to the object at ffff0000f244fe00 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 24 bytes inside of 128-byte region [ffff0000f244fe00, ffff0000f244fe80) The buggy address belongs to the physical page: page:00000000801c042c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13244f flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 0000000000000000 dead000000000001 ffff0000c0002300 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f244fd00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000f244fd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff0000f244fe00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000f244fe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000f244ff00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Unable to handle kernel paging request at virtual address e0a6c08b4000021e KASAN: maybe wild-memory-access in range [0x053a045a000010f0-0x053a045a000010f7] Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 [e0a6c08b4000021e] address between user and kernel address ranges Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 4337 Comm: syz-executor Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 pstate: 02400005 (nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : __list_del_entry_valid+0x7c/0x15c lib/list_debug.c:59 lr : __list_del_entry_valid+0x50/0x15c lib/list_debug.c:47 sp : ffff800021b57920 x29: ffff800021b57920 x28: 1fffe0001b543684 x27: dfff800000000000 x26: 0000000000000000 x25: 1fffe0001b543685 x24: ffff0000d77d8498 x23: ffff0000d77d8490 x22: dfff800000000000 x21: 053a045a000010f1 x20: ffff0000d51d6000 x19: ffff0000f244fe00 x18: 1fffe00033c2177e x17: ffff8000163dd000 x16: ffff800008043dd4 x15: 0000000040000000 x14: 0000000000000001 x13: 1ffff000031fab68 x12: 0000000000000000 x11: ff00800010d6ea00 x10: 0000000000000000 x9 : ffff80001d66f950 x8 : 00a7408b4000021e x7 : ffff800011cfc180 x6 : ffff80000825b754 x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff80000a932b2c x2 : dead000000000122 x1 : 0000000000000008 x0 : 0000000000000000 Call trace: __list_del_entry_valid+0x7c/0x15c lib/list_debug.c:59 __list_del_entry include/linux/list.h:141 [inline] list_del_rcu include/linux/rculist.h:157 [inline] hci_chan_del+0x70/0x1bc net/bluetooth/hci_conn.c:2785 l2cap_conn_free net/bluetooth/l2cap_core.c:1868 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put+0x80/0x10c net/bluetooth/l2cap_core.c:1882 l2cap_chan_destroy net/bluetooth/l2cap_core.c:502 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_chan_put+0x194/0x26c net/bluetooth/l2cap_core.c:529 l2cap_sock_release+0x160/0x1c8 net/bluetooth/l2cap_sock.c:1494 __sock_release net/socket.c:654 [inline] sock_close+0xac/0x1ec net/socket.c:1400 __fput+0x1b4/0x7b0 fs/file_table.c:320 ____fput+0x20/0x30 fs/file_table.c:348 task_work_run+0x1f4/0x280 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x54c/0x19ac kernel/exit.c:887 do_group_exit+0x198/0x238 kernel/exit.c:1030 __do_sys_exit_group kernel/exit.c:1041 [inline] __se_sys_exit_group kernel/exit.c:1039 [inline] __wake_up_parent+0x0/0x60 kernel/exit.c:1039 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:589 Code: 91008902 eb0202bf 54000520 d343fea8 (38766908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 91008902 add x2, x8, #0x22 4: eb0202bf cmp x21, x2 8: 54000520 b.eq 0xac // b.none c: d343fea8 lsr x8, x21, #3 * 10: 38766908 ldrb w8, [x8, x22] <-- trapping instruction