==================================================================
BUG: KASAN: slab-use-after-free in hci_uart_write_work+0x82d/0x960 drivers/bluetooth/hci_ldisc.c:165
Read of size 4 at addr ffff8880223b7a70 by task kworker/1:0/24

CPU: 1 UID: 0 PID: 24 Comm: kworker/1:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events hci_uart_write_work
Call Trace:
 <TASK>
 __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
 hci_uart_write_work+0x82d/0x960 drivers/bluetooth/hci_ldisc.c:165
 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+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 5861:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:330 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:356
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4191 [inline]
 slab_alloc_node mm/slub.c:4240 [inline]
 kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4292
 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:659
 alloc_skb include/linux/skbuff.h:1336 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:509 [inline]
 hci_cmd_sync_alloc+0x39/0x3a0 net/bluetooth/hci_sync.c:58
 hci_cmd_sync_add net/bluetooth/hci_sync.c:99 [inline]
 __hci_cmd_sync_sk+0x157/0xc90 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+0x2c/0x160 net/bluetooth/hci_sync.c:3694
 hci_init_stage_sync net/bluetooth/hci_sync.c:3609 [inline]
 hci_init1_sync net/bluetooth/hci_sync.c:3741 [inline]
 hci_init_sync net/bluetooth/hci_sync.c:4853 [inline]
 hci_dev_init_sync net/bluetooth/hci_sync.c:5045 [inline]
 hci_dev_open_sync+0x16f6/0x2430 net/bluetooth/hci_sync.c:5123
 hci_dev_do_open+0x2a/0x90 net/bluetooth/hci_core.c:430
 hci_power_on+0x131/0x610 net/bluetooth/hci_core.c:959
 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+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x730 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 ffff8880223b7a00
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 112 bytes inside of
 freed 240-byte region [ffff8880223b7a00, ffff8880223b7af0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x223b7
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff888140ea68c0 dead000000000122 0000000000000000
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 10026, tgid 10025 (syz.2.1034), ts 446222192760, free_ts 446210345283
 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:2492 [inline]
 allocate_slab mm/slub.c:2660 [inline]
 new_slab+0x247/0x330 mm/slub.c:2714
 ___slab_alloc+0xcf2/0x1750 mm/slub.c:3901
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3992
 __slab_alloc_node mm/slub.c:4067 [inline]
 slab_alloc_node mm/slub.c:4228 [inline]
 kmem_cache_alloc_node_noprof+0xf5/0x3b0 mm/slub.c:4292
 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:659
 alloc_skb include/linux/skbuff.h:1336 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 audit_buffer_alloc kernel/audit.c:1795 [inline]
 audit_log_start+0x2ea/0x7f0 kernel/audit.c:1913
 common_lsm_audit+0xb2/0x300 security/lsm_audit.c:442
 slow_avc_audit+0x186/0x210 security/selinux/avc.c:779
 avc_audit security/selinux/include/avc.h:131 [inline]
 avc_has_perm+0x1b5/0x1f0 security/selinux/avc.c:1198
 file_map_prot_check+0x317/0x360 security/selinux/hooks.c:3932
 selinux_mmap_file+0x143/0x1b0 security/selinux/hooks.c:3985
 security_mmap_file+0x82a/0x990 security/security.c:3012
page last free pid 24 tgid 24 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
 __folio_put+0x329/0x450 mm/swap.c:112
 folio_put include/linux/mm.h:1360 [inline]
 aio_free_ring+0x2dd/0x4f0 fs/aio.c:345
 free_ioctx+0x21/0xa0 fs/aio.c:622
 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+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff8880223b7900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880223b7980: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
>ffff8880223b7a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff8880223b7a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff8880223b7b00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
==================================================================
CPU: 1 UID: 0 PID: 24 Comm: kworker/1:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events hci_uart_write_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x3d/0x1f0 lib/dump_stack.c:120
 vpanic+0x6e8/0x7a0 kernel/panic.c:430
 panic+0xca/0xd0 kernel/panic.c:566
 check_panic_on_warn kernel/panic.c:323 [inline]
 check_panic_on_warn+0xab/0xb0 kernel/panic.c:318
 end_report+0x107/0x170 mm/kasan/report.c:227
 kasan_report+0xee/0x110 mm/kasan/report.c:597
 hci_uart_write_work+0x82d/0x960 drivers/bluetooth/hci_ldisc.c:165
 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+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Kernel Offset: disabled
Rebooting in 86400 seconds..