syzbot

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BUG: KASAN: slab-use-after-free in force_wakeup_write+0x14d/0x170 drivers/bluetooth/hci_vhci.c:188
Read of size 1 at addr ffff88805b970231 by task syz.4.2872/19083

CPU: 0 UID: 0 PID: 19083 Comm: syz.4.2872 Not tainted 6.14.0-rc5-syzkaller-00137-g00a7d39898c8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xd9/0x110 mm/kasan/report.c:634
 force_wakeup_write+0x14d/0x170 drivers/bluetooth/hci_vhci.c:188
 full_proxy_write+0x13c/0x200 fs/debugfs/file.c:398
 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: 0033:0x7f46de78d169
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:00007f46dc5f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f46de9a5fa0 RCX: 00007f46de78d169
RDX: 0000000000000001 RSI: 0000400000001780 RDI: 0000000000000003
RBP: 00007f46de80e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f46de9a5fa0 R15: 00007fffc59aac08
 </TASK>

Allocated by task 13212:
 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
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4294 [inline]
 __kmalloc_noprof+0x21c/0x510 mm/slub.c:4306
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 ieee802_11_parse_elems_full+0x1d0/0x3240 net/mac80211/parse.c:1013
 ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2397 [inline]
 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2404 [inline]
 ieee80211_inform_bss+0xfd/0x1100 net/mac80211/scan.c:79
 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline]
 cfg80211_inform_single_bss_data+0x8f9/0x1df0 net/wireless/scan.c:2367
 cfg80211_inform_bss_data+0x205/0x3ba0 net/wireless/scan.c:3222
 cfg80211_inform_bss_frame_data+0x272/0x7a0 net/wireless/scan.c:3317
 ieee80211_bss_info_update+0x311/0xab0 net/mac80211/scan.c:226
 ieee80211_rx_bss_info net/mac80211/ibss.c:1102 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1581 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x189c/0x2f50 net/mac80211/ibss.c:1608
 ieee80211_iface_process_skb net/mac80211/iface.c:1612 [inline]
 ieee80211_iface_work+0xc15/0xf50 net/mac80211/iface.c:1666
 cfg80211_wiphy_work+0x3ed/0x570 net/wireless/core.c:435
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 13212:
 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:576
 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:4609 [inline]
 kfree+0x2c4/0x4d0 mm/slub.c:4757
 ieee80211_inform_bss+0x76e/0x1100 net/mac80211/scan.c:160
 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline]
 cfg80211_inform_single_bss_data+0x8f9/0x1df0 net/wireless/scan.c:2367
 cfg80211_inform_bss_data+0x205/0x3ba0 net/wireless/scan.c:3222
 cfg80211_inform_bss_frame_data+0x272/0x7a0 net/wireless/scan.c:3317
 ieee80211_bss_info_update+0x311/0xab0 net/mac80211/scan.c:226
 ieee80211_rx_bss_info net/mac80211/ibss.c:1102 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1581 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x189c/0x2f50 net/mac80211/ibss.c:1608
 ieee80211_iface_process_skb net/mac80211/iface.c:1612 [inline]
 ieee80211_iface_work+0xc15/0xf50 net/mac80211/iface.c:1666
 cfg80211_wiphy_work+0x3ed/0x570 net/wireless/core.c:435
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff88805b970000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 561 bytes inside of
 freed 1024-byte region [ffff88805b970000, ffff88805b970400)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805b977000 pfn:0x5b970
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88801b041dc0 ffffea0001fa5010 ffffea0000498010
raw: ffff88805b977000 000000000010000e 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801b041dc0 ffffea0001fa5010 ffffea0000498010
head: ffff88805b977000 000000000010000e 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea00016e5c01 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 5987, tgid 5987 (syz-executor), ts 80117002386, free_ts 79470593598
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739
 alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab mm/slub.c:2587 [inline]
 new_slab+0x23d/0x330 mm/slub.c:2640
 ___slab_alloc+0xc5d/0x1720 mm/slub.c:3826
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 __kmalloc_cache_noprof+0xfa/0x410 mm/slub.c:4320
 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:179
 chrdev_open+0x237/0x6a0 fs/char_dev.c:414
 do_dentry_open+0x735/0x1c40 fs/open.c:956
 vfs_open+0x82/0x3f0 fs/open.c:1086
 do_open fs/namei.c:3830 [inline]
 path_openat+0x1e88/0x2d80 fs/namei.c:3989
 do_filp_open+0x20c/0x470 fs/namei.c:4016
 do_sys_openat2+0x17a/0x1e0 fs/open.c:1428
page last free pid 5958 tgid 5954 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660
 kimage_free_page_list+0x130/0x230 kernel/kexec_core.c:314
 kimage_alloc_normal_control_pages kernel/kexec_core.c:379 [inline]
 kimage_alloc_control_pages+0x38f/0x8e0 kernel/kexec_core.c:460
 kimage_alloc_init kernel/kexec.c:67 [inline]
 do_kexec_load+0x47e/0x8c0 kernel/kexec.c:130
 __do_sys_kexec_load kernel/kexec.c:261 [inline]
 __se_sys_kexec_load kernel/kexec.c:242 [inline]
 __x64_sys_kexec_load+0x1bf/0x230 kernel/kexec.c:242
 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

Memory state around the buggy address:
 ffff88805b970100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805b970180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88805b970200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88805b970280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805b970300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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