================================================================== BUG: KASAN: slab-use-after-free in force_devcd_write+0x312/0x340 drivers/bluetooth/hci_vhci.c:327 Read of size 8 at addr ffff8880291b8000 by task syz.1.922/10708 CPU: 0 UID: 0 PID: 10708 Comm: syz.1.922 Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:408 [inline] print_report+0xcd/0x680 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 force_devcd_write+0x312/0x340 drivers/bluetooth/hci_vhci.c:327 full_proxy_write+0x13f/0x200 fs/debugfs/file.c:398 vfs_write+0x29d/0x1150 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: 0033:0x7f776d38e929 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:00007f776e296038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f776d5b5fa0 RCX: 00007f776d38e929 RDX: 000000000000000e RSI: 0000000000000000 RDI: 0000000000000008 RBP: 00007f776d410b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f776d5b5fa0 R15: 00007ffd1a7d2658 Allocated by task 6865: 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:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4328 [inline] __kmalloc_node_track_caller_noprof+0x221/0x510 mm/slub.c:4347 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:601 pskb_expand_head+0x238/0x1030 net/core/skbuff.c:2241 __skb_cow include/linux/skbuff.h:3777 [inline] skb_cow_head include/linux/skbuff.h:3811 [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:86 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:1708 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 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 6865: 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:247 [inline] __kasan_slab_free+0x51/0x70 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+0x2b4/0x4d0 mm/slub.c:4842 skb_kfree_head net/core/skbuff.c:1048 [inline] skb_free_head+0x114/0x210 net/core/skbuff.c:1060 skb_release_data+0x776/0x9c0 net/core/skbuff.c:1087 skb_release_all net/core/skbuff.c:1152 [inline] __kfree_skb net/core/skbuff.c:1166 [inline] sk_skb_reason_drop+0x129/0x1a0 net/core/skbuff.c:1204 kfree_skb_reason include/linux/skbuff.h:1275 [inline] __netif_receive_skb_core.constprop.0+0x57b/0x4a00 net/core/dev.c:5951 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:5975 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6090 process_backlog+0x442/0x15e0 net/core/dev.c:6442 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7414 napi_poll net/core/dev.c:7478 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7605 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+0x8ab/0x43e0 net/core/dev.c:4740 dev_queue_xmit include/linux/netdevice.h:3355 [inline] batadv_send_skb_packet+0x58e/0x780 net/batman-adv/send.c:108 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:1708 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 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 ffff8880291b8000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes inside of freed 1024-byte region [ffff8880291b8000, ffff8880291b8400) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880291b9800 pfn:0x291b8 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 ffff88801b841dc0 ffffea0001df0810 ffffea0001e1fa10 raw: ffff8880291b9800 000000000010000e 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b841dc0 ffffea0001df0810 ffffea0001e1fa10 head: ffff8880291b9800 000000000010000e 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000a46e01 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 49, tgid 49 (kworker/u8:3), ts 12012126664, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959 alloc_slab_page mm/slub.c:2453 [inline] allocate_slab mm/slub.c:2619 [inline] new_slab+0x94/0x330 mm/slub.c:2673 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949 __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __kmalloc_cache_node_noprof+0x100/0x420 mm/slub.c:4367 kmalloc_node_noprof include/linux/slab.h:928 [inline] blk_mq_alloc_hctx block/blk-mq.c:3997 [inline] blk_mq_alloc_and_init_hctx+0x639/0x11c0 block/blk-mq.c:4500 __blk_mq_realloc_hw_ctxs+0x495/0x610 block/blk-mq.c:4531 blk_mq_realloc_hw_ctxs block/blk-mq.c:4558 [inline] blk_mq_init_allocated_queue+0x3af/0x1240 block/blk-mq.c:4590 blk_mq_alloc_queue+0x1be/0x290 block/blk-mq.c:4400 scsi_alloc_sdev+0x88f/0xd80 drivers/scsi/scsi_scan.c:339 scsi_probe_and_add_lun+0x76b/0xd80 drivers/scsi/scsi_scan.c:1210 __scsi_scan_target+0x1e8/0x580 drivers/scsi/scsi_scan.c:1775 scsi_scan_channel drivers/scsi/scsi_scan.c:1863 [inline] scsi_scan_channel+0x149/0x1e0 drivers/scsi/scsi_scan.c:1839 scsi_scan_host_selected+0x302/0x400 drivers/scsi/scsi_scan.c:1892 page_owner free stack trace missing Memory state around the buggy address: ffff8880291b7f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880291b7f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880291b8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880291b8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880291b8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================