================================================================== BUG: KASAN: slab-use-after-free in force_devcd_write+0x312/0x340 drivers/bluetooth/hci_vhci.c:327 Read of size 8 at addr ffff888025141000 by task syz.2.2483/18604 CPU: 0 UID: 0 PID: 18604 Comm: syz.2.2483 Not tainted 6.17.0-rc1-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 force_devcd_write+0x312/0x340 drivers/bluetooth/hci_vhci.c:327 full_proxy_write+0x12e/0x1a0 fs/debugfs/file.c:388 vfs_write+0x29d/0x11d0 fs/read_write.c:684 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f96d658ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f96d73e4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f96d67b5fa0 RCX: 00007f96d658ebe9 RDX: 000000000000000e RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f96d6611e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f96d67b6038 R14: 00007f96d67b5fa0 R15: 00007ffec59d3c38 Allocated by task 1166: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4365 [inline] __kmalloc_node_track_caller_noprof+0x221/0x510 mm/slub.c:4384 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:600 pskb_expand_head+0x238/0x1030 net/core/skbuff.c:2240 __skb_cow include/linux/skbuff.h:3806 [inline] skb_cow_head include/linux/skbuff.h:3840 [inline] batadv_skb_head_push+0xf5/0x290 net/batman-adv/mesh-interface.c:71 batadv_send_skb_packet+0x11b/0x780 net/batman-adv/send.c:85 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:392 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:420 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x734/0x920 net/batman-adv/bat_iv_ogm.c:1702 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 1166: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4879 skb_kfree_head net/core/skbuff.c:1047 [inline] skb_free_head+0x114/0x210 net/core/skbuff.c:1059 skb_release_data+0x795/0x9e0 net/core/skbuff.c:1086 skb_release_all net/core/skbuff.c:1151 [inline] __kfree_skb net/core/skbuff.c:1165 [inline] sk_skb_reason_drop+0x129/0x1a0 net/core/skbuff.c:1203 kfree_skb_reason include/linux/skbuff.h:1275 [inline] __netif_receive_skb_core.constprop.0+0x57a/0x48c0 net/core/dev.c:5953 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:5977 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6092 process_backlog+0x442/0x15e0 net/core/dev.c:6444 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7489 napi_poll net/core/dev.c:7552 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7679 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 do_softirq kernel/softirq.c:480 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:467 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:407 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline] __dev_queue_xmit+0xb06/0x4490 net/core/dev.c:4740 dev_queue_xmit include/linux/netdevice.h:3358 [inline] batadv_send_skb_packet+0x58e/0x780 net/batman-adv/send.c:107 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:392 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:420 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x734/0x920 net/batman-adv/bat_iv_ogm.c:1702 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff888025141000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes inside of freed 1024-byte region [ffff888025141000, ffff888025141400) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25140 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 ffff88801b841dc0 ffffea0000961600 dead000000000002 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b841dc0 ffffea0000961600 dead000000000002 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000945001 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5198, tgid 5198 (init), ts 35624151553, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab mm/slub.c:2655 [inline] new_slab+0x247/0x330 mm/slub.c:2709 ___slab_alloc+0xcf2/0x1740 mm/slub.c:3891 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3981 __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] __do_kmalloc_node mm/slub.c:4364 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4377 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] tomoyo_init_log+0x1385/0x2140 security/tomoyo/audit.c:275 tomoyo_supervisor+0x302/0x13b0 security/tomoyo/common.c:2198 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline] tomoyo_env_perm+0x191/0x200 security/tomoyo/environ.c:63 tomoyo_environ security/tomoyo/domain.c:672 [inline] tomoyo_find_next_domain+0xec2/0x20b0 security/tomoyo/domain.c:888 tomoyo_bprm_check_security security/tomoyo/tomoyo.c:102 [inline] tomoyo_bprm_check_security+0x12e/0x1d0 security/tomoyo/tomoyo.c:92 security_bprm_check+0x1b9/0x1e0 security/security.c:1302 search_binary_handler fs/exec.c:1660 [inline] exec_binprm fs/exec.c:1702 [inline] bprm_execve fs/exec.c:1754 [inline] bprm_execve+0x81a/0x1640 fs/exec.c:1730 do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1860 page_owner free stack trace missing Memory state around the buggy address: ffff888025140f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888025140f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888025141000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888025141080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888025141100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================