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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 ffff888027fb0000 by task syz.1.3123/21053
CPU: 0 UID: 0 PID: 21053 Comm: syz.1.3123 Not tainted 6.14.0-rc7-syzkaller-00186-gd07de43e3f05 #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: 0033:0x7f5d52d8d169
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:00007f5d53bb5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5d52fa5fa0 RCX: 00007f5d52d8d169
RDX: 000000000000000e RSI: 0000000000000000 RDI: 000000000000000a
RBP: 00007f5d52e0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5d52fa5fa0 R15: 00007ffccf3dc658
</TASK>
Allocated by task 8570:
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_node_track_caller_noprof+0x222/0x510 mm/slub.c:4313
kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:537
pskb_expand_head+0x237/0x1050 net/core/skbuff.c:2185
__skb_cow include/linux/skbuff.h:3769 [inline]
skb_cow_head include/linux/skbuff.h:3803 [inline]
batadv_skb_head_push+0xf5/0x290 net/batman-adv/soft-interface.c:72
batadv_send_skb_packet+0x115/0x770 net/batman-adv/send.c:86
batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:391 [inline]
batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:419 [inline]
batadv_iv_send_outstanding_bat_ogm_packet+0x70f/0x8d0 net/batman-adv/bat_iv_ogm.c:1699
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 8570:
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
skb_kfree_head net/core/skbuff.c:996 [inline]
skb_free_head+0x108/0x1d0 net/core/skbuff.c:1008
skb_release_data+0x560/0x730 net/core/skbuff.c:1035
skb_release_all net/core/skbuff.c:1100 [inline]
__kfree_skb net/core/skbuff.c:1114 [inline]
sk_skb_reason_drop+0x129/0x1a0 net/core/skbuff.c:1152
kfree_skb_reason include/linux/skbuff.h:1271 [inline]
__netif_receive_skb_core.constprop.0+0x575/0x4330 net/core/dev.c:5870
__netif_receive_skb_one_core+0xb1/0x1e0 net/core/dev.c:5894
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6009
process_backlog+0x443/0x15f0 net/core/dev.c:6357
__napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7191
napi_poll net/core/dev.c:7260 [inline]
net_rx_action+0xa94/0x1010 net/core/dev.c:7382
handle_softirqs+0x213/0x8f0 kernel/softirq.c:561
do_softirq kernel/softirq.c:462 [inline]
do_softirq+0xb2/0xf0 kernel/softirq.c:449
__local_bh_enable_ip+0x100/0x120 kernel/softirq.c:389
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline]
__dev_queue_xmit+0x8b0/0x43e0 net/core/dev.c:4679
dev_queue_xmit include/linux/netdevice.h:3313 [inline]
batadv_send_skb_packet+0x588/0x770 net/batman-adv/send.c:108
batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:391 [inline]
batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:419 [inline]
batadv_iv_send_outstanding_bat_ogm_packet+0x70f/0x8d0 net/batman-adv/bat_iv_ogm.c:1699
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 ffff888027fb0000
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 0 bytes inside of
freed 1024-byte region [ffff888027fb0000, ffff888027fb0400)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888027fb5000 pfn:0x27fb0
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 ffffea0000e84610 ffff88801b040888
raw: ffff888027fb5000 0000000000100003 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801b041dc0 ffffea0000e84610 ffff88801b040888
head: ffff888027fb5000 0000000000100003 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea00009fec01 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 36, tgid 36 (kworker/u8:2), ts 9462781357, free_ts 0
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_slab_page mm/slub.c:2425 [inline]
allocate_slab mm/slub.c:2587 [inline]
new_slab+0x94/0x330 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_node_noprof+0x101/0x420 mm/slub.c:4333
kmalloc_node_noprof include/linux/slab.h:924 [inline]
blk_mq_alloc_hctx block/blk-mq.c:3945 [inline]
blk_mq_alloc_and_init_hctx+0x639/0x11b0 block/blk-mq.c:4448
blk_mq_realloc_hw_ctxs+0x8e0/0xbe0 block/blk-mq.c:4481
blk_mq_init_allocated_queue+0x39e/0x11f0 block/blk-mq.c:4535
blk_mq_alloc_queue+0x1c3/0x290 block/blk-mq.c:4348
scsi_alloc_sdev+0x890/0xd80 drivers/scsi/scsi_scan.c:338
scsi_probe_and_add_lun+0x789/0xda0 drivers/scsi/scsi_scan.c:1209
__scsi_scan_target+0x1ea/0x580 drivers/scsi/scsi_scan.c:1774
scsi_scan_channel drivers/scsi/scsi_scan.c:1862 [inline]
scsi_scan_channel+0x149/0x1e0 drivers/scsi/scsi_scan.c:1838
scsi_scan_host_selected+0x302/0x400 drivers/scsi/scsi_scan.c:1891
page_owner free stack trace missing
Memory state around the buggy address:
ffff888027faff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888027faff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888027fb0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888027fb0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888027fb0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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