==================================================================
BUG: KASAN: slab-use-after-free in pwq_release_workfn+0x339/0x380 kernel/workqueue.c:4124
Read of size 4 at addr ffff88802a0371c0 by task pool_workqueue_/3

CPU: 0 PID: 3 Comm: pool_workqueue_ Not tainted 6.6.0-rc1-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xc4/0x620 mm/kasan/report.c:475
 kasan_report+0xda/0x110 mm/kasan/report.c:588
 pwq_release_workfn+0x339/0x380 kernel/workqueue.c:4124
 kthread_worker_fn+0x2fc/0xa80 kernel/kthread.c:823
 kthread+0x33a/0x430 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
 </TASK>

Allocated by task 1866:
 kasan_save_stack+0x33/0x50 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+0xa3/0xb0 mm/kasan/common.c:383
 kmalloc include/linux/slab.h:599 [inline]
 kzalloc include/linux/slab.h:720 [inline]
 alloc_workqueue+0x16f/0x1490 kernel/workqueue.c:4684
 kvm_mmu_init_tdp_mmu+0x23/0x100 arch/x86/kvm/mmu/tdp_mmu.c:19
 kvm_mmu_init_vm+0x248/0x2e0 arch/x86/kvm/mmu/mmu.c:6180
 kvm_arch_init_vm+0x39/0x720 arch/x86/kvm/x86.c:12311
 kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1222 [inline]
 kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:5089 [inline]
 kvm_dev_ioctl+0xa31/0x1c20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:5131
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl fs/ioctl.c:857 [inline]
 __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 1866:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 ____kasan_slab_free+0x138/0x190 mm/kasan/common.c:200
 kasan_slab_free include/linux/kasan.h:164 [inline]
 __cache_free mm/slab.c:3370 [inline]
 __do_kmem_cache_free mm/slab.c:3557 [inline]
 __kmem_cache_free+0xcc/0x2d0 mm/slab.c:3564
 alloc_workqueue+0xe76/0x1490 kernel/workqueue.c:4746
 kvm_mmu_init_tdp_mmu+0x23/0x100 arch/x86/kvm/mmu/tdp_mmu.c:19
 kvm_mmu_init_vm+0x248/0x2e0 arch/x86/kvm/mmu/mmu.c:6180
 kvm_arch_init_vm+0x39/0x720 arch/x86/kvm/x86.c:12311
 kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1222 [inline]
 kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:5089 [inline]
 kvm_dev_ioctl+0xa31/0x1c20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:5131
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl fs/ioctl.c:857 [inline]
 __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Last potentially related work creation:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 __kasan_record_aux_stack+0x78/0x80 mm/kasan/generic.c:492
 __call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:2653
 pwq_release_workfn+0x244/0x380 kernel/workqueue.c:4138
 kthread_worker_fn+0x2fc/0xa80 kernel/kthread.c:823
 kthread+0x33a/0x430 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Second to last potentially related work creation:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 __kasan_record_aux_stack+0x78/0x80 mm/kasan/generic.c:492
 __call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:2653
 pwq_release_workfn+0x244/0x380 kernel/workqueue.c:4138
 kthread_worker_fn+0x2fc/0xa80 kernel/kthread.c:823
 kthread+0x33a/0x430 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

The buggy address belongs to the object at ffff88802a037000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 448 bytes inside of
 freed 512-byte region [ffff88802a037000, ffff88802a037200)

The buggy address belongs to the physical page:
page:ffffea0000a80dc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2a037
flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0x4()
raw: 00fff00000000800 ffff888012c40600 ffffea0000afdc90 ffffea0000736fd0
raw: 0000000000000000 ffff88802a037000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x242020(__GFP_HIGH|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 1122, tgid 1122 (kworker/u16:9), ts 173360121955, free_ts 173345834013
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536
 prep_new_page mm/page_alloc.c:1543 [inline]
 get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170
 __alloc_pages_slowpath.constprop.0+0x2dd/0x2360 mm/page_alloc.c:3960
 __alloc_pages+0x411/0x4a0 mm/page_alloc.c:4439
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 kmem_getpages mm/slab.c:1356 [inline]
 cache_grow_begin+0x99/0x3a0 mm/slab.c:2550
 cache_alloc_refill+0x294/0x3a0 mm/slab.c:2923
 ____cache_alloc mm/slab.c:2999 [inline]
 ____cache_alloc mm/slab.c:2982 [inline]
 __do_cache_alloc mm/slab.c:3182 [inline]
 slab_alloc_node mm/slab.c:3230 [inline]
 __kmem_cache_alloc_node+0x3c9/0x470 mm/slab.c:3521
 kmalloc_trace+0x25/0xe0 mm/slab_common.c:1114
 kmalloc include/linux/slab.h:599 [inline]
 batadv_forw_packet_alloc+0x3a8/0x4e0 net/batman-adv/send.c:519
 batadv_iv_ogm_aggregate_new+0x132/0x4a0 net/batman-adv/bat_iv_ogm.c:562
 batadv_iv_ogm_queue_add net/batman-adv/bat_iv_ogm.c:670 [inline]
 batadv_iv_ogm_schedule_buff+0xe94/0x1510 net/batman-adv/bat_iv_ogm.c:849
 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:868 [inline]
 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:861 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0x31e/0x8c0 net/batman-adv/bat_iv_ogm.c:1712
 process_one_work+0x887/0x15d0 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x8bb/0x1290 kernel/workqueue.c:2784
 kthread+0x33a/0x430 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1136 [inline]
 free_unref_page_prepare+0x476/0xa40 mm/page_alloc.c:2312
 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2405
 slab_destroy mm/slab.c:1608 [inline]
 slabs_destroy+0x85/0xc0 mm/slab.c:1628
 cache_flusharray mm/slab.c:3341 [inline]
 ___cache_free+0x2b7/0x420 mm/slab.c:3404
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x4c/0x1b0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x18b/0x1d0 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook mm/slab.h:762 [inline]
 slab_alloc_node mm/slab.c:3237 [inline]
 __kmem_cache_alloc_node+0x167/0x470 mm/slab.c:3521
 __do_kmalloc_node mm/slab_common.c:1022 [inline]
 __kmalloc_node+0x52/0x110 mm/slab_common.c:1030
 kmalloc_node include/linux/slab.h:619 [inline]
 __vmalloc_area_node mm/vmalloc.c:3125 [inline]
 __vmalloc_node_range+0x3e9/0x1540 mm/vmalloc.c:3320
 __vmalloc_node mm/vmalloc.c:3385 [inline]
 vzalloc+0x6b/0x80 mm/vmalloc.c:3458
 alloc_counters net/ipv6/netfilter/ip6_tables.c:815 [inline]
 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:837 [inline]
 get_entries net/ipv6/netfilter/ip6_tables.c:1039 [inline]
 do_ip6t_get_ctl+0x68d/0xab0 net/ipv6/netfilter/ip6_tables.c:1669
 nf_getsockopt+0x76/0xe0 net/netfilter/nf_sockopt.c:116
 ipv6_getsockopt+0x1f9/0x2b0 net/ipv6/ipv6_sockglue.c:1500
 tcp_getsockopt+0x97/0xf0 net/ipv4/tcp.c:4284
 __sys_getsockopt+0x220/0x6a0 net/socket.c:2354

Memory state around the buggy address:
 ffff88802a037080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802a037100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802a037180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff88802a037200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802a037280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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