================================================================== BUG: KASAN: slab-use-after-free in pwq_release_workfn+0x339/0x380 kernel/workqueue.c:4124 Read of size 4 at addr ffff888023affdc0 by task pool_workqueue_/3 CPU: 3 PID: 3 Comm: pool_workqueue_ Not tainted 6.5.0-syzkaller-11329-g708283abf896 #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 24986: 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 24986: 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+0x5d2/0x1060 kernel/workqueue.c:1799 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 ffff888023affc00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 448 bytes inside of freed 512-byte region [ffff888023affc00, ffff888023affe00) The buggy address belongs to the physical page: page:ffffea00008ebf00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23afc head:ffffea00008ebf00 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5211, tgid 5211 (kworker/3:4), ts 49686445232, free_ts 21792383010 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+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] mca_alloc net/ipv6/mcast.c:880 [inline] __ipv6_dev_mc_inc+0x2b7/0xc40 net/ipv6/mcast.c:936 addrconf_join_solict net/ipv6/addrconf.c:2189 [inline] addrconf_dad_begin net/ipv6/addrconf.c:4033 [inline] addrconf_dad_work+0x232/0x13e0 net/ipv6/addrconf.c:4158 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 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 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:186 [inline] slab_post_alloc_hook mm/slab.h:762 [inline] slab_alloc_node mm/slub.c:3478 [inline] __kmem_cache_alloc_node+0x19b/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] kernfs_iop_get_link fs/kernfs/symlink.c:135 [inline] kernfs_iop_get_link+0x65/0x850 fs/kernfs/symlink.c:126 vfs_readlink+0x1db/0x370 fs/namei.c:5108 do_readlinkat+0x29b/0x2f0 fs/stat.c:528 __do_sys_readlink fs/stat.c:549 [inline] __se_sys_readlink fs/stat.c:546 [inline] __x64_sys_readlink+0x78/0xb0 fs/stat.c:546 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 Memory state around the buggy address: ffff888023affc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888023affd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888023affd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888023affe00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888023affe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================