syzbot

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BUG: KASAN: slab-use-after-free in __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166
Read of size 1 at addr ffff888034fbbb30 by task kworker/1:6/5779

CPU: 1 UID: 0 PID: 5779 Comm: kworker/1:6 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events l2cap_chan_timeout
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:574
 kasan_check_byte include/linux/kasan.h:402 [inline]
 lock_acquire+0x84/0x350 kernel/locking/lockdep.c:5844
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
 _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166
 rt_mutex_slowunlock+0xb8/0x300 kernel/locking/rtmutex.c:1430
 process_one_work+0x98b/0x1630 kernel/workqueue.c:3318
 process_scheduled_works kernel/workqueue.c:3401 [inline]
 worker_thread+0xb49/0x1140 kernel/workqueue.c:3482
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 15781:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5425
 _kmalloc_noprof include/linux/slab.h:967 [inline]
 _kzalloc_noprof include/linux/slab.h:1284 [inline]
 l2cap_conn_add+0xaa/0x970 net/bluetooth/l2cap_core.c:7001
 l2cap_chan_connect+0x6a8/0xed0 net/bluetooth/l2cap_core.c:7192
 l2cap_sock_connect+0x5ea/0x7f0 net/bluetooth/l2cap_sock.c:257
 __sys_connect_file net/socket.c:2163 [inline]
 __sys_connect+0x315/0x450 net/socket.c:2182
 __do_sys_connect net/socket.c:2188 [inline]
 __se_sys_connect net/socket.c:2185 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2185
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 16549:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2700 [inline]
 slab_free mm/slub.c:6284 [inline]
 kfree+0x1c5/0x6c0 mm/slub.c:6599
 hci_disconn_cfm include/net/bluetooth/hci_core.h:2154 [inline]
 hci_conn_hash_flush+0x10d/0x260 net/bluetooth/hci_conn.c:2734
 hci_dev_close_sync+0x821/0x10e0 net/bluetooth/hci_sync.c:5371
 hci_dev_do_close net/bluetooth/hci_core.c:502 [inline]
 hci_dev_close+0x108/0x260 net/bluetooth/hci_core.c:527
 sock_do_ioctl+0x101/0x320 net/socket.c:1328
 sock_ioctl+0x5c9/0x7f0 net/socket.c:1449
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888034fbb800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 816 bytes inside of
 freed 1024-byte region [ffff888034fbb800, ffff888034fbbc00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x34fb8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff88813fea6dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88813fea6dc0 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5569, tgid 5569 (dhcpcd-run-hook), ts 72853083420, free_ts 72763635259
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1866
 prep_new_page mm/page_alloc.c:1874 [inline]
 get_page_from_freelist+0x265c/0x26e0 mm/page_alloc.c:3953
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5296
 alloc_slab_page mm/slub.c:3289 [inline]
 allocate_slab+0x74/0x5e0 mm/slub.c:3404
 new_slab mm/slub.c:3447 [inline]
 refill_objects+0x33c/0x3d0 mm/slub.c:7226
 refill_sheaf mm/slub.c:2827 [inline]
 __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4665
 alloc_from_pcs mm/slub.c:4763 [inline]
 slab_alloc_node mm/slub.c:4897 [inline]
 __do_kmalloc_node mm/slub.c:5308 [inline]
 __kmalloc_noprof+0x530/0x7b0 mm/slub.c:5322
 _kmalloc_noprof include/linux/slab.h:971 [inline]
 load_elf_phdrs fs/binfmt_elf.c:540 [inline]
 load_elf_binary+0x318/0x29b0 fs/binfmt_elf.c:869
 search_binary_handler fs/exec.c:1664 [inline]
 exec_binprm fs/exec.c:1696 [inline]
 bprm_execve+0x94a/0x1510 fs/exec.c:1748
 do_execveat_common+0x50d/0x690 fs/exec.c:1846
 __do_sys_execve fs/exec.c:1930 [inline]
 __se_sys_execve fs/exec.c:1924 [inline]
 __x64_sys_execve+0x97/0xc0 fs/exec.c:1924
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5564 tgid 5564 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1413 [inline]
 __free_frozen_pages+0x10af/0x1190 mm/page_alloc.c:2957
 __slab_free+0x252/0x2a0 mm/slub.c:5646
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4583 [inline]
 slab_alloc_node mm/slub.c:4912 [inline]
 kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4919
 vm_area_alloc+0x24/0x140 mm/vma_init.c:32
 __mmap_new_vma mm/vma.c:2547 [inline]
 __mmap_region mm/vma.c:2771 [inline]
 mmap_region+0x1203/0x2280 mm/vma.c:2857
 do_mmap+0xc2f/0x10c0 mm/mmap.c:560
 vm_mmap_pgoff+0x2cc/0x4f0 mm/util.c:581
 ksys_mmap_pgoff+0x4e8/0x720 mm/mmap.c:606
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888034fbba00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888034fbba80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888034fbbb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888034fbbb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888034fbbc00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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