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BUG: KASAN: slab-use-after-free in __vhost_vq_attach_worker drivers/vhost/vhost.c:631 [inline]
BUG: KASAN: slab-use-after-free in vhost_dev_set_owner+0x96c/0xa70 drivers/vhost/vhost.c:823
Read of size 4 at addr ffff888028657d5c by task syz-executor.3/938

CPU: 1 PID: 938 Comm: syz-executor.3 Not tainted 6.4.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x64/0xb0 lib/dump_stack.c:106
 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351
 print_report mm/kasan/report.c:462 [inline]
 kasan_report+0x11c/0x130 mm/kasan/report.c:572
 __vhost_vq_attach_worker drivers/vhost/vhost.c:631 [inline]
 vhost_dev_set_owner+0x96c/0xa70 drivers/vhost/vhost.c:823
 vhost_net_set_owner drivers/vhost/net.c:1687 [inline]
 vhost_net_ioctl+0x885/0x12c0 drivers/vhost/net.c:1737
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x123/0x190 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f957ce8c389
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f957db20168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f957cfabf80 RCX: 00007f957ce8c389
RDX: 0000000000000000 RSI: 000040000000af01 RDI: 0000000000000003
RBP: 00007f957ced7493 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffd42f82ff R14: 00007f957db20300 R15: 0000000000022000
 </TASK>

Allocated by task 938:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 ____kasan_kmalloc mm/kasan/common.c:333 [inline]
 __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383
 kmalloc include/linux/slab.h:559 [inline]
 kzalloc include/linux/slab.h:680 [inline]
 vhost_worker_create+0x8b/0x2b0 drivers/vhost/vhost.c:596
 vhost_dev_set_owner+0x34a/0xa70 drivers/vhost/vhost.c:811
 vhost_net_set_owner drivers/vhost/net.c:1687 [inline]
 vhost_net_ioctl+0x885/0x12c0 drivers/vhost/net.c:1737
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x123/0x190 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 954:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:521
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
 kasan_slab_free include/linux/kasan.h:162 [inline]
 slab_free_hook mm/slub.c:1781 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807
 slab_free mm/slub.c:3786 [inline]
 __kmem_cache_free+0xaf/0x2d0 mm/slub.c:3799
 vhost_worker_destroy drivers/vhost/vhost.c:569 [inline]
 vhost_workers_free drivers/vhost/vhost.c:584 [inline]
 vhost_dev_cleanup+0x5a2/0x7b0 drivers/vhost/vhost.c:922
 vhost_dev_reset_owner+0x1d/0x150 drivers/vhost/vhost.c:854
 vhost_net_reset_owner drivers/vhost/net.c:1621 [inline]
 vhost_net_ioctl+0x91b/0x12c0 drivers/vhost/net.c:1735
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x123/0x190 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff888028657d40
 which belongs to the cache kmalloc-cg-32 of size 32
The buggy address is located 28 bytes inside of
 freed 32-byte region [ffff888028657d40, ffff888028657d60)

The buggy address belongs to the physical page:
page:ffffea0000a195c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888028657d00 pfn:0x28657
memcg:ffff888020c47001
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000200 ffff88801144d8c0 ffffea0000ab0a40 dead000000000004
raw: ffff888028657d00 000000008040003e 00000001ffffffff ffff888020c47001
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 12845, tgid 12837 (syz-executor.2), ts 118702808671, free_ts 118701766031
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2db/0x350 mm/page_alloc.c:1731
 prep_new_page mm/page_alloc.c:1738 [inline]
 get_page_from_freelist+0xf41/0x2c00 mm/page_alloc.c:3502
 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4768
 alloc_slab_page mm/slub.c:1851 [inline]
 allocate_slab+0x25f/0x390 mm/slub.c:1998
 new_slab mm/slub.c:2051 [inline]
 ___slab_alloc+0xa91/0x1400 mm/slub.c:3192
 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3291
 __slab_alloc_node mm/slub.c:3344 [inline]
 slab_alloc_node mm/slub.c:3441 [inline]
 __kmem_cache_alloc_node+0x136/0x320 mm/slub.c:3490
 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1057
 kmalloc include/linux/slab.h:559 [inline]
 kzalloc include/linux/slab.h:680 [inline]
 vhost_worker_create+0x8b/0x2b0 drivers/vhost/vhost.c:596
 vhost_dev_set_owner+0x34a/0xa70 drivers/vhost/vhost.c:811
 vhost_net_set_owner drivers/vhost/net.c:1687 [inline]
 vhost_net_ioctl+0x885/0x12c0 drivers/vhost/net.c:1737
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x123/0x190 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1302 [inline]
 free_unref_page_prepare+0x62e/0xcb0 mm/page_alloc.c:2564
 free_unref_page+0x33/0x370 mm/page_alloc.c:2659
 mm_free_pgd kernel/fork.c:806 [inline]
 __mmdrop+0xc3/0x3f0 kernel/fork.c:924
 exit_mm kernel/exit.c:567 [inline]
 do_exit+0x85d/0x24d0 kernel/exit.c:861
 do_group_exit+0xb4/0x250 kernel/exit.c:1024
 get_signal+0x1d36/0x1fa0 kernel/signal.c:2876
 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff888028657c00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
 ffff888028657c80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
>ffff888028657d00: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
                                                    ^
 ffff888028657d80: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc
 ffff888028657e00: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc
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