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BUG: KASAN: slab-use-after-free in force_devcd_write+0x317/0x330 drivers/bluetooth/hci_vhci.c:327
Read of size 8 at addr ffff88807c6c3800 by task syz.8.7763/3663
CPU: 0 UID: 0 PID: 3663 Comm: syz.8.7763 Not tainted 6.14.0-rc7-syzkaller-00137-g5fc319360819 #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_devcd_write+0x317/0x330 drivers/bluetooth/hci_vhci.c:327
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: 0033:0x7f7881b8d169
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:00007f7882904038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7881da5fa0 RCX: 00007f7881b8d169
RDX: 000000000000000e RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f7881c0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f7881da5fa0 R15: 00007ffed5bbb6c8
</TASK>
Allocated by task 3392:
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]
afs_alloc_call+0x51/0x640 fs/afs/rxrpc.c:144
afs_charge_preallocation+0xff/0x330 fs/afs/rxrpc.c:728
afs_open_socket+0x2b3/0x380 fs/afs/rxrpc.c:95
afs_net_init+0x95d/0xc60 fs/afs/main.c:123
ops_init+0x1df/0x5f0 net/core/net_namespace.c:138
setup_net+0x21f/0x860 net/core/net_namespace.c:362
copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:516
create_new_namespaces+0x3ea/0xad0 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228
ksys_unshare+0x45d/0xa40 kernel/fork.c:3342
__do_sys_unshare kernel/fork.c:3413 [inline]
__se_sys_unshare kernel/fork.c:3411 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:3411
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 21309:
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
afs_free_call+0x303/0x440 fs/afs/rxrpc.c:188
afs_put_call+0x188/0x1e0 fs/afs/rxrpc.c:210
rxrpc_discard_prealloc+0x67b/0x930 net/rxrpc/call_accept.c:224
rxrpc_listen+0x117/0x330 net/rxrpc/af_rxrpc.c:246
afs_close_socket+0x97/0x340 fs/afs/rxrpc.c:113
afs_net_exit+0x93/0x130 fs/afs/main.c:155
ops_exit_list+0xb0/0x180 net/core/net_namespace.c:172
cleanup_net+0x5c6/0xb30 net/core/net_namespace.c:652
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 ffff88807c6c3800
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 0 bytes inside of
freed 1024-byte region [ffff88807c6c3800, ffff88807c6c3c00)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807c6c5800 pfn:0x7c6c0
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 ffffea00015db010 ffffea00017ac410
raw: ffff88807c6c5800 000000000010000a 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801b041dc0 ffffea00015db010 ffffea00017ac410
head: ffff88807c6c5800 000000000010000a 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001f1b001 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 100, tgid 100 (kworker/0:1H), ts 113095418486, free_ts 113056502852
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:4740
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]
__do_kmalloc_node mm/slub.c:4293 [inline]
__kmalloc_noprof+0x2ec/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_scan_rx+0x474/0xac0 net/mac80211/scan.c:340
__ieee80211_rx_handle_packet net/mac80211/rx.c:5246 [inline]
ieee80211_rx_list+0x1bd7/0x2970 net/mac80211/rx.c:5483
page last free pid 6256 tgid 6246 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
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4115 [inline]
slab_alloc_node mm/slub.c:4164 [inline]
__kmalloc_cache_noprof+0x243/0x410 mm/slub.c:4320
kmalloc_noprof include/linux/slab.h:901 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
kobject_uevent_env+0x265/0x1870 lib/kobject_uevent.c:540
__kobject_del+0x168/0x1f0 lib/kobject.c:601
kobject_cleanup lib/kobject.c:680 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x327/0x5a0 lib/kobject.c:737
net_rx_queue_update_kobjects+0x478/0x5f0 net/core/net-sysfs.c:1209
remove_queue_kobjects net/core/net-sysfs.c:1984 [inline]
netdev_unregister_kobject+0x150/0x270 net/core/net-sysfs.c:2138
unregister_netdevice_many_notify+0x13aa/0x1f30 net/core/dev.c:11923
setup_net+0x4ae/0x860 net/core/net_namespace.c:389
copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:516
create_new_namespaces+0x3ea/0xad0 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228
ksys_unshare+0x45d/0xa40 kernel/fork.c:3342
Memory state around the buggy address:
ffff88807c6c3700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807c6c3780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88807c6c3800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88807c6c3880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88807c6c3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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