================================================================== BUG: KASAN: slab-use-after-free in pwq_release_workfn+0x339/0x380 kernel/workqueue.c:4124 Read of size 4 at addr ffff888023c86dc0 by task pool_workqueue_/3 CPU: 1 PID: 3 Comm: pool_workqueue_ Not tainted 6.6.0-rc1-syzkaller-00014-ga747acc0b752 #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 10690: 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+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 __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 10690: 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:164 [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+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 __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 __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 ffff888023c86c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 448 bytes inside of freed 512-byte region [ffff888023c86c00, ffff888023c86e00) The buggy address belongs to the physical page: page:ffffea00008f2100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23c84 head:ffffea00008f2100 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 7629, tgid 7627 (syz-executor.1), ts 1414621587284, free_ts 1414613450948 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+0x1d0/0x4a0 mm/page_alloc.c:4426 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2298 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab+0x251/0x380 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 kmalloc_trace+0x25/0xe0 mm/slab_common.c:1114 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] device_private_init drivers/base/core.c:3469 [inline] device_add+0xd18/0x1ac0 drivers/base/core.c:3520 netdev_register_kobject+0x183/0x3f0 net/core/net-sysfs.c:2044 register_netdevice+0xbcb/0x1490 net/core/dev.c:10136 __ip_tunnel_create+0x4a1/0x670 net/ipv4/ip_tunnel.c:267 ip_tunnel_init_net+0x237/0x5e0 net/ipv4/ip_tunnel.c:1091 ops_init+0xb9/0x650 net/core/net_namespace.c:136 setup_net+0x422/0xa40 net/core/net_namespace.c:339 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 __unfreeze_partials+0x21d/0x240 mm/slub.c:2655 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x6a/0x170 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/slub.c:3478 [inline] kmem_cache_alloc_node+0x185/0x3f0 mm/slub.c:3523 __alloc_skb+0x287/0x330 net/core/skbuff.c:640 alloc_skb include/linux/skbuff.h:1286 [inline] nlmsg_new include/net/netlink.h:999 [inline] inet6_netconf_notify_devconf+0x87/0x180 net/ipv6/addrconf.c:582 __addrconf_sysctl_register+0x293/0x3f0 net/ipv6/addrconf.c:7149 addrconf_init_net+0x526/0x8f0 net/ipv6/addrconf.c:7258 ops_init+0xb9/0x650 net/core/net_namespace.c:136 setup_net+0x422/0xa40 net/core/net_namespace.c:339 copy_net_ns+0x2fa/0x670 net/core/net_namespace.c:491 create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:228 Memory state around the buggy address: ffff888023c86c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888023c86d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888023c86d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888023c86e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888023c86e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================