================================================================== BUG: KASAN: slab-use-after-free in pwq_release_workfn+0x339/0x380 kernel/workqueue.c:4124 Read of size 4 at addr ffff8880499581c0 by task pool_workqueue_/3 CPU: 2 PID: 3 Comm: pool_workqueue_ Not tainted 6.6.0-rc2-syzkaller-00386-g3aba70aed91f #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+0x2ff/0xac0 kernel/kthread.c:823 kthread+0x33c/0x440 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 29675: 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 29675: 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+0x2ff/0xac0 kernel/kthread.c:823 kthread+0x33c/0x440 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 insert_work+0x38/0x230 kernel/workqueue.c:1647 __queue_work+0xb77/0x1050 kernel/workqueue.c:1803 call_timer_fn+0x19e/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 ffff888049958000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 448 bytes inside of freed 512-byte region [ffff888049958000, ffff888049958200) The buggy address belongs to the physical page: page:ffffea0001265600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x49958 flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0x4() raw: 00fff00000000800 ffff888012c40600 ffffea000077f350 ffffea00008556d0 raw: 0000000000000000 ffff888049958000 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 0x2420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 5171, tgid 5171 (syz-executor.0), ts 50058589388, free_ts 0 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_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+0x3c5/0x470 mm/slab.c:3521 __do_kmalloc_node mm/slab_common.c:1022 [inline] __kmalloc+0x4f/0x100 mm/slab_common.c:1036 kmalloc include/linux/slab.h:603 [inline] kzalloc include/linux/slab.h:720 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x337/0x1e70 net/ipv6/route.c:3749 addrconf_f6i_alloc+0x38f/0x660 net/ipv6/route.c:4572 ipv6_add_addr+0x4c2/0x2000 net/ipv6/addrconf.c:1114 add_addr+0xe0/0x350 net/ipv6/addrconf.c:3139 add_v4_addrs+0x68d/0x9d0 net/ipv6/addrconf.c:3204 addrconf_sit_config net/ipv6/addrconf.c:3455 [inline] addrconf_init_auto_addrs+0x4ea/0x810 net/ipv6/addrconf.c:3492 addrconf_notify+0xe65/0x1920 net/ipv6/addrconf.c:3679 notifier_call_chain+0xb6/0x3b0 kernel/notifier.c:93 page_owner free stack trace missing Memory state around the buggy address: ffff888049958080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888049958100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888049958180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888049958200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888049958280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================