syzbot

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BUG: KASAN: slab-use-after-free in msft_opcode_get+0x6d/0x80 drivers/bluetooth/hci_vhci.c:222
Read of size 2 at addr ffff8880284fd232 by task syz.2.3479/16612

CPU: 1 UID: 0 PID: 16612 Comm: syz.2.3479 Tainted: G     U              6.15.0-syzkaller-13743-g8630c59e9936 #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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+0xcd/0x680 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 msft_opcode_get+0x6d/0x80 drivers/bluetooth/hci_vhci.c:222
 simple_attr_read+0x16b/0x370 fs/libfs.c:1335
 debugfs_attr_read+0x76/0xa0 fs/debugfs/file.c:534
 full_proxy_read+0x13c/0x200 fs/debugfs/file.c:393
 vfs_read+0x1e1/0xc60 fs/read_write.c:570
 ksys_read+0x12a/0x250 fs/read_write.c:715
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f20ce18e929
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:00007f20cefbb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f20ce3b5fa0 RCX: 00007f20ce18e929
RDX: 000000000000ffff RSI: 0000200000006740 RDI: 0000000000000005
RBP: 00007f20ce210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f20ce3b5fa0 R15: 00007fff5df543d8
 </TASK>

Allocated by task 12375:
 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:4328 [inline]
 __kmalloc_noprof+0x223/0x510 mm/slub.c:4340
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 rds_message_alloc+0x42/0x230 net/rds/message.c:291
 rds_message_map_pages+0x3b/0x3f0 net/rds/message.c:341
 rds_cong_update_alloc+0x3d/0xa0 net/rds/cong.c:423
 rds_send_xmit+0x1298/0x25c0 net/rds/send.c:219
 rds_send_worker+0x8f/0x2e0 net/rds/threads.c:200
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 12375:
 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:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kfree+0x2b4/0x4d0 mm/slub.c:4842
 rds_message_put+0x93f/0xe70 net/rds/message.c:182
 rds_send_xmit+0x777/0x25c0 net/rds/send.c:415
 rds_send_worker+0x8f/0x2e0 net/rds/threads.c:200
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880284fd000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 562 bytes inside of
 freed 1024-byte region [ffff8880284fd000, ffff8880284fd400)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880284fd000 pfn:0x284f8
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 ffff88801b441dc0 ffffea0000c2e210 ffffea0000a3fe10
raw: ffff8880284fd000 000000000010000a 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801b441dc0 ffffea0000c2e210 ffffea0000a3fe10
head: ffff8880284fd000 000000000010000a 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000a13e01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 13, tgid 13 (kworker/u8:1), ts 14092303673, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959
 alloc_slab_page mm/slub.c:2453 [inline]
 allocate_slab mm/slub.c:2619 [inline]
 new_slab+0x94/0x330 mm/slub.c:2673
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949
 __slab_alloc_node mm/slub.c:4024 [inline]
 slab_alloc_node mm/slub.c:4185 [inline]
 __kmalloc_cache_node_noprof+0x100/0x420 mm/slub.c:4367
 kmalloc_node_noprof include/linux/slab.h:928 [inline]
 blk_mq_alloc_hctx block/blk-mq.c:3997 [inline]
 blk_mq_alloc_and_init_hctx+0x639/0x11c0 block/blk-mq.c:4500
 __blk_mq_realloc_hw_ctxs+0x495/0x610 block/blk-mq.c:4531
 blk_mq_realloc_hw_ctxs block/blk-mq.c:4558 [inline]
 blk_mq_init_allocated_queue+0x3af/0x1240 block/blk-mq.c:4590
 blk_mq_alloc_queue+0x1be/0x290 block/blk-mq.c:4400
 scsi_alloc_sdev+0x88f/0xd80 drivers/scsi/scsi_scan.c:339
 scsi_probe_and_add_lun+0x76b/0xd80 drivers/scsi/scsi_scan.c:1210
 __scsi_scan_target+0x1e8/0x580 drivers/scsi/scsi_scan.c:1775
 scsi_scan_channel drivers/scsi/scsi_scan.c:1863 [inline]
 scsi_scan_channel+0x149/0x1e0 drivers/scsi/scsi_scan.c:1839
 scsi_scan_host_selected+0x302/0x400 drivers/scsi/scsi_scan.c:1892
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880284fd100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880284fd180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880284fd200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8880284fd280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880284fd300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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