================================================================== BUG: KASAN: slab-use-after-free in pwq_release_workfn+0x339/0x380 kernel/workqueue.c:4124 Read of size 4 at addr ffff888012c9cdc0 by task pool_workqueue_/3 CPU: 3 PID: 3 Comm: pool_workqueue_ Not tainted 6.5.0-syzkaller-10898-gfdde61878047 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __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 Allocated by task 23382: 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+0xa2/0xb0 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+0x14e/0x360 arch/x86/kvm/mmu/mmu.c:6220 kvm_arch_init_vm+0x67/0x740 arch/x86/kvm/x86.c:12305 kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1196 [inline] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:5063 [inline] kvm_dev_ioctl+0xa31/0x1c20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:5105 __do_compat_sys_ioctl+0x2bf/0x330 fs/ioctl.c:972 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Freed by task 23382: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3822 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+0x14e/0x360 arch/x86/kvm/mmu/mmu.c:6220 kvm_arch_init_vm+0x67/0x740 arch/x86/kvm/x86.c:12305 kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1196 [inline] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:5063 [inline] kvm_dev_ioctl+0xa31/0x1c20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:5105 __do_compat_sys_ioctl+0x2bf/0x330 fs/ioctl.c:972 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492 insert_work+0x38/0x230 kernel/workqueue.c:1647 __queue_work+0xb7e/0x1060 kernel/workqueue.c:1803 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1746 [inline] __run_timers+0x585/0xb10 kernel/time/timer.c:2022 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035 __do_softirq+0x218/0x965 kernel/softirq.c:553 Second to last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492 insert_work+0x38/0x230 kernel/workqueue.c:1647 __queue_work+0xb7e/0x1060 kernel/workqueue.c:1803 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1746 [inline] __run_timers+0x585/0xb10 kernel/time/timer.c:2022 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035 __do_softirq+0x218/0x965 kernel/softirq.c:553 The buggy address belongs to the object at ffff888012c9cc00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 448 bytes inside of freed 512-byte region [ffff888012c9cc00, ffff888012c9ce00) The buggy address belongs to the physical page: page:ffffea00004b2700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12c9c head:ffffea00004b2700 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888012c42c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 22258, tgid 22256 (syz-executor.0), ts 604381928615, free_ts 600820523518 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+0x10a9/0x31e0 mm/page_alloc.c:3183 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4439 __alloc_pages_node include/linux/gfp.h:237 [inline] alloc_slab_page mm/slub.c:1872 [inline] allocate_slab+0xa1/0x380 mm/slub.c:2017 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8be/0x1570 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x137/0x350 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1022 [inline] __kmalloc_node+0x52/0x110 mm/slab_common.c:1030 kmalloc_array_node include/linux/slab.h:697 [inline] kcalloc_node include/linux/slab.h:702 [inline] memcg_alloc_slab_cgroups+0xa9/0x170 mm/memcontrol.c:2895 account_slab mm/slab.h:636 [inline] allocate_slab+0x2cb/0x380 mm/slub.c:2035 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8be/0x1570 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x137/0x350 mm/slub.c:3517 kmalloc_trace+0x25/0xe0 mm/slab_common.c:1114 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:1073 [inline] kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1216 [inline] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:5063 [inline] kvm_dev_ioctl+0x1543/0x1c20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:5105 __do_compat_sys_ioctl+0x2bf/0x330 fs/ioctl.c:972 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 skb_kfree_head net/core/skbuff.c:939 [inline] skb_free_head+0x110/0x1b0 net/core/skbuff.c:951 skb_release_data+0x5ba/0x870 net/core/skbuff.c:981 skb_release_all net/core/skbuff.c:1047 [inline] __kfree_skb net/core/skbuff.c:1061 [inline] consume_skb net/core/skbuff.c:1277 [inline] consume_skb+0xd2/0x170 net/core/skbuff.c:1271 nlmon_xmit+0xa5/0xe0 drivers/net/nlmon.c:15 __netdev_start_xmit include/linux/netdevice.h:4889 [inline] netdev_start_xmit include/linux/netdevice.h:4903 [inline] xmit_one net/core/dev.c:3544 [inline] dev_hard_start_xmit+0x13d/0x6c0 net/core/dev.c:3560 __dev_queue_xmit+0x9be/0x3d80 net/core/dev.c:4340 dev_queue_xmit include/linux/netdevice.h:3082 [inline] __netlink_deliver_tap_skb net/netlink/af_netlink.c:307 [inline] __netlink_deliver_tap net/netlink/af_netlink.c:325 [inline] netlink_deliver_tap+0xaa0/0xd10 net/netlink/af_netlink.c:338 netlink_deliver_tap_kernel net/netlink/af_netlink.c:347 [inline] netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x5f0/0x810 net/netlink/af_netlink.c:1368 netlink_sendmsg+0x93c/0xe40 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg+0xd9/0x180 net/socket.c:753 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2540 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2594 __sys_sendmsg+0x117/0x1e0 net/socket.c:2623 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 Memory state around the buggy address: ffff888012c9cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888012c9cd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888012c9cd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888012c9ce00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888012c9ce80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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