================================================================== BUG: KASAN: slab-use-after-free in hci_uart_write_work+0x2ca/0x550 drivers/bluetooth/hci_ldisc.c:165 Read of size 8 at addr ffff88803dd0f218 by task kworker/1:6/5941 CPU: 1 UID: 0 PID: 5941 Comm: kworker/1:6 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events hci_uart_write_work Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 hci_uart_write_work+0x2ca/0x550 drivers/bluetooth/hci_ldisc.c:165 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 5844: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4948 [inline] slab_alloc_node mm/slub.c:5258 [inline] kmem_cache_alloc_node_noprof+0x43c/0x720 mm/slub.c:5310 __alloc_skb+0x255/0x430 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:510 [inline] hci_cmd_sync_alloc+0x3d/0x3b0 net/bluetooth/hci_sync.c:58 hci_cmd_sync_add net/bluetooth/hci_sync.c:99 [inline] __hci_cmd_sync_sk+0x1a7/0xc70 net/bluetooth/hci_sync.c:168 __hci_cmd_sync_status_sk net/bluetooth/hci_sync.c:263 [inline] __hci_cmd_sync_status net/bluetooth/hci_sync.c:287 [inline] hci_read_local_features_sync net/bluetooth/hci_sync.c:3708 [inline] hci_init_stage_sync net/bluetooth/hci_sync.c:3623 [inline] hci_init1_sync net/bluetooth/hci_sync.c:3755 [inline] hci_init_sync net/bluetooth/hci_sync.c:4885 [inline] hci_dev_init_sync net/bluetooth/hci_sync.c:5077 [inline] hci_dev_open_sync+0x14b2/0x2dc0 net/bluetooth/hci_sync.c:5155 hci_dev_do_open net/bluetooth/hci_core.c:430 [inline] hci_power_on+0x1b4/0x720 net/bluetooth/hci_core.c:959 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 The buggy address belongs to the object at ffff88803dd0f140 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 216 bytes inside of freed 240-byte region [ffff88803dd0f140, ffff88803dd0f230) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3dd0f anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff8881416bb8c0 ffffea0000bf2380 dead000000000005 raw: 0000000000000000 00000000000c000c 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 3462, tgid 3462 (kworker/u8:10), ts 345097772498, free_ts 344905456450 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xf2b/0x1960 mm/slub.c:4651 __slab_alloc+0x65/0x100 mm/slub.c:4774 __slab_alloc_node mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:5246 [inline] kmem_cache_alloc_noprof+0x40f/0x710 mm/slub.c:5265 __build_skb net/core/skbuff.c:474 [inline] __netdev_alloc_skb+0x226/0x960 net/core/skbuff.c:784 __netdev_alloc_skb_ip_align include/linux/skbuff.h:3504 [inline] netdev_alloc_skb_ip_align include/linux/skbuff.h:3514 [inline] batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:566 [inline] batadv_iv_ogm_queue_add+0x825/0xd30 net/batman-adv/bat_iv_ogm.c:677 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:854 [inline] batadv_iv_ogm_schedule+0xb48/0xf00 net/batman-adv/bat_iv_ogm.c:873 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1709 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 page last free pid 15 tgid 15 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xd70/0x1870 kernel/rcu/tree.c:2857 handle_softirqs+0x27d/0x850 kernel/softirq.c:626 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1067 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Memory state around the buggy address: ffff88803dd0f100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff88803dd0f180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803dd0f200: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc ^ ffff88803dd0f280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803dd0f300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ==================================================================