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BUG: KASAN: slab-use-after-free in hci_cmd_timeout+0x216/0x260 net/bluetooth/hci_core.c:1522
Read of size 2 at addr ffff888011d0dcf8 by task kworker/u33:2/5235

CPU: 2 PID: 5235 Comm: kworker/u33:2 Not tainted 6.9.0-syzkaller-07726-g3c999d1ae3c7 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: hci0 hci_cmd_timeout
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 hci_cmd_timeout+0x216/0x260 net/bluetooth/hci_core.c:1522
 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5235:
 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:312 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3871 [inline]
 slab_alloc_node mm/slub.c:3918 [inline]
 kmem_cache_alloc+0x136/0x330 mm/slub.c:3925
 skb_clone+0x190/0x3f0 net/core/skbuff.c:2052
 hci_send_cmd_sync net/bluetooth/hci_core.c:4123 [inline]
 hci_cmd_work+0x66a/0x710 net/bluetooth/hci_core.c:4143
 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 7450:
 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:579
 poison_slab_object mm/kasan/common.c:240 [inline]
 __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2121 [inline]
 slab_free mm/slub.c:4353 [inline]
 kmem_cache_free+0x12e/0x390 mm/slub.c:4417
 kfree_skbmem+0x10e/0x200 net/core/skbuff.c:1131
 __kfree_skb net/core/skbuff.c:1188 [inline]
 kfree_skb_reason+0x138/0x210 net/core/skbuff.c:1223
 kfree_skb include/linux/skbuff.h:1257 [inline]
 __hci_req_sync+0x61d/0x980 net/bluetooth/hci_request.c:184
 hci_req_sync+0x97/0xd0 net/bluetooth/hci_request.c:206
 hci_inquiry+0x3f7/0x970 net/bluetooth/hci_core.c:427
 hci_sock_ioctl+0x2bb/0x880 net/bluetooth/hci_sock.c:1153
 hci_sock_compat_ioctl net/bluetooth/hci_sock.c:1177 [inline]
 hci_sock_compat_ioctl+0x68/0x80 net/bluetooth/hci_sock.c:1166
 compat_sock_ioctl+0x181/0x7f0 net/socket.c:3521
 __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1004
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

The buggy address belongs to the object at ffff888011d0dcc0
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 56 bytes inside of
 freed 240-byte region [ffff888011d0dcc0, ffff888011d0ddb0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11d0c
head: order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff8880167ee780 ffffea0000476700 dead000000000002
raw: 0000000000000000 0000000000190019 00000001ffffffff 0000000000000000
head: 00fff00000000840 ffff8880167ee780 ffffea0000476700 dead000000000002
head: 0000000000000000 0000000000190019 00000001ffffffff 0000000000000000
head: 00fff00000000001 ffffea0000474301 dead000000000122 00000000ffffffff
head: 0000000200000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 3896, tgid 3896 (kworker/2:2), ts 85664614656, free_ts 85175023845
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317
 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page mm/slub.c:2190 [inline]
 allocate_slab mm/slub.c:2353 [inline]
 new_slab+0xcc/0x3a0 mm/slub.c:2406
 ___slab_alloc+0xd28/0x1810 mm/slub.c:3592
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3682
 __slab_alloc_node mm/slub.c:3735 [inline]
 slab_alloc_node mm/slub.c:3908 [inline]
 kmem_cache_alloc_node+0x10a/0x350 mm/slub.c:3961
 __alloc_skb+0x2b3/0x380 net/core/skbuff.c:656
 alloc_skb include/linux/skbuff.h:1308 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x2a4/0xc80 drivers/net/netdevsim/dev.c:850
 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page last free pid 6414 tgid 6414 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347
 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487
 mm_free_pgd kernel/fork.c:804 [inline]
 __mmdrop+0xd5/0x470 kernel/fork.c:920
 mmdrop include/linux/sched/mm.h:54 [inline]
 __mmput+0x40a/0x4d0 kernel/fork.c:1357
 mmput+0x62/0x70 kernel/fork.c:1368
 exit_mm kernel/exit.c:569 [inline]
 do_exit+0x999/0x2c10 kernel/exit.c:865
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1027
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 __ia32_sys_exit_group+0x3e/0x50 kernel/exit.c:1036
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Memory state around the buggy address:
 ffff888011d0db80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888011d0dc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
>ffff888011d0dc80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
                                                                ^
 ffff888011d0dd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888011d0dd80: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
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