syzbot

==================================================================
BUG: KASAN: slab-use-after-free in force_devcd_write+0x31f/0x350 drivers/bluetooth/hci_vhci.c:327
Read of size 8 at addr ffff8881412fa000 by task syz.7.30/6314

CPU: 0 UID: 0 PID: 6314 Comm: syz.7.30 Not tainted 6.13.0-rc7-syzkaller-00189-g595523945be0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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+0xc3/0x620 mm/kasan/report.c:489
 kasan_report+0xd9/0x110 mm/kasan/report.c:602
 force_devcd_write+0x31f/0x350 drivers/bluetooth/hci_vhci.c:327
 full_proxy_write+0xfd/0x1b0 fs/debugfs/file.c:369
 vfs_write+0x24c/0x1150 fs/read_write.c:677
 ksys_write+0x12b/0x250 fs/read_write.c:731
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f09ec385d29
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:00007f09ed1cb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f09ec576080 RCX: 00007f09ec385d29
RDX: 000000000000000e RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f09ec401b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f09ec576080 R15: 00007ffca3d3ddd8
 </TASK>

Allocated by task 6057:
 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
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 vhci_open+0x4c/0x430 drivers/bluetooth/hci_vhci.c:634
 misc_open+0x35a/0x420 drivers/char/misc.c:165
 chrdev_open+0x237/0x6a0 fs/char_dev.c:414
 do_dentry_open+0xf59/0x1ea0 fs/open.c:945
 vfs_open+0x82/0x3f0 fs/open.c:1075
 do_open fs/namei.c:3828 [inline]
 path_openat+0x1e6a/0x2d60 fs/namei.c:3987
 do_filp_open+0x20c/0x470 fs/namei.c:4014
 do_sys_openat2+0x17a/0x1e0 fs/open.c:1402
 do_sys_open fs/open.c:1417 [inline]
 __do_sys_openat fs/open.c:1433 [inline]
 __se_sys_openat fs/open.c:1428 [inline]
 __x64_sys_openat+0x175/0x210 fs/open.c:1428
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6263:
 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:582
 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:2353 [inline]
 slab_free mm/slub.c:4613 [inline]
 kfree+0x14f/0x4b0 mm/slub.c:4761
 vhci_release+0xbb/0xf0 drivers/bluetooth/hci_vhci.c:670
 __fput+0x3f8/0xb60 fs/file_table.c:450
 task_work_run+0x14e/0x250 kernel/task_work.c:239
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0xad8/0x2d70 kernel/exit.c:938
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
 get_signal+0x2576/0x2610 kernel/signal.c:3017
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8881412fa000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 0 bytes inside of
 freed 1024-byte region [ffff8881412fa000, ffff8881412fa400)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881412fb000 pfn:0x1412f8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801ac41dc0 ffffea0005361600 dead000000000002
raw: ffff8881412fb000 000000000010000f 00000001f5000000 0000000000000000
head: 057ff00000000040 ffff88801ac41dc0 ffffea0005361600 dead000000000002
head: ffff8881412fb000 000000000010000f 00000001f5000000 0000000000000000
head: 057ff00000000003 ffffea000504be01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
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 1, tgid 1 (swapper/0), ts 2848360563, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1558
 prep_new_page mm/page_alloc.c:1566 [inline]
 get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3476
 __alloc_pages_noprof+0x223/0x25b0 mm/page_alloc.c:4753
 alloc_pages_mpol_noprof+0x2c8/0x620 mm/mempolicy.c:2269
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab mm/slub.c:2589 [inline]
 new_slab+0x2c9/0x410 mm/slub.c:2642
 ___slab_alloc+0xce2/0x1650 mm/slub.c:3830
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3920
 __slab_alloc_node mm/slub.c:3995 [inline]
 slab_alloc_node mm/slub.c:4156 [inline]
 __do_kmalloc_node mm/slub.c:4297 [inline]
 __kmalloc_node_noprof+0x2f0/0x520 mm/slub.c:4304
 __kvmalloc_node_noprof+0xad/0x1a0 mm/util.c:645
 bucket_table_alloc.isra.0+0x86/0x460 lib/rhashtable.c:186
 rhashtable_init_noprof+0x43b/0x7d0 lib/rhashtable.c:1071
 netlink_proto_init+0xbc/0x320 net/netlink/af_netlink.c:2928
 do_one_initcall+0x128/0x630 init/main.c:1266
 do_initcall_level init/main.c:1328 [inline]
 do_initcalls init/main.c:1344 [inline]
 do_basic_setup init/main.c:1363 [inline]
 kernel_init_freeable+0x58f/0x8b0 init/main.c:1577
 kernel_init+0x1c/0x2b0 init/main.c:1466
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8881412f9f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881412f9f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881412fa000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8881412fa080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881412fa100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================