================================================================== BUG: KASAN: slab-use-after-free in pwq_release_workfn+0x2ce/0x330 kernel/workqueue.c:4124 Read of size 4 at addr ffff88811c01f9c0 by task pool_workqueue_/3 CPU: 1 PID: 3 Comm: pool_workqueue_ Not tainted 6.5.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x3d/0x60 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+0x2ce/0x330 kernel/workqueue.c:4124 kthread_worker_fn+0x21a/0x6e0 kernel/kthread.c:823 kthread+0x278/0x330 kernel/kthread.c:388 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Allocated by task 2825: 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:582 [inline] kzalloc include/linux/slab.h:703 [inline] alloc_workqueue+0x11a/0x1100 kernel/workqueue.c:4684 kvm_mmu_init_tdp_mmu+0x1e/0xf0 arch/x86/kvm/mmu/tdp_mmu.c:19 kvm_mmu_init_vm+0x226/0x2b0 arch/x86/kvm/mmu/mmu.c:6180 kvm_arch_init_vm+0x1f/0x6b0 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+0x96f/0x17a0 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+0x12b/0x1a0 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 2825: 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:1792 [inline] slab_free_freelist_hook+0x10b/0x1e0 mm/slub.c:1818 slab_free mm/slub.c:3801 [inline] __kmem_cache_free+0xba/0x330 mm/slub.c:3814 alloc_workqueue+0xafa/0x1100 kernel/workqueue.c:4746 kvm_mmu_init_tdp_mmu+0x1e/0xf0 arch/x86/kvm/mmu/tdp_mmu.c:19 kvm_mmu_init_vm+0x226/0x2b0 arch/x86/kvm/mmu/mmu.c:6180 kvm_arch_init_vm+0x1f/0x6b0 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+0x96f/0x17a0 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+0x12b/0x1a0 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 The buggy address belongs to the object at ffff88811c01f800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 448 bytes inside of freed 512-byte region [ffff88811c01f800, ffff88811c01fa00) The buggy address belongs to the physical page: page:ffffea0004700700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11c01c head:ffffea0004700700 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0x200000000000840(slab|head|node=0|zone=2) page_type: 0xffffffff() raw: 0200000000000840 ffff888100041c80 0000000000000000 dead000000000001 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 1949, tgid 1949 (udevadm), ts 6306230964, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x27e/0x2f0 mm/page_alloc.c:1530 prep_new_page mm/page_alloc.c:1537 [inline] get_page_from_freelist+0xca9/0x2f50 mm/page_alloc.c:3200 __alloc_pages+0x1d0/0x470 mm/page_alloc.c:4456 alloc_slab_page mm/slub.c:1862 [inline] allocate_slab+0x24b/0x360 mm/slub.c:2009 new_slab mm/slub.c:2062 [inline] ___slab_alloc+0x7a9/0x1000 mm/slub.c:3215 __slab_alloc.constprop.0+0x4d/0x90 mm/slub.c:3314 __slab_alloc_node mm/slub.c:3367 [inline] slab_alloc_node mm/slub.c:3460 [inline] __kmem_cache_alloc_node+0x143/0x390 mm/slub.c:3509 kmalloc_trace+0x25/0xb0 mm/slab_common.c:1075 kmalloc include/linux/slab.h:582 [inline] kzalloc include/linux/slab.h:703 [inline] kernfs_fop_open+0x259/0xd30 fs/kernfs/file.c:670 do_dentry_open+0x5db/0x11b0 fs/open.c:929 do_open fs/namei.c:3639 [inline] path_openat+0x18b8/0x27c0 fs/namei.c:3796 do_filp_open+0x1bc/0x400 fs/namei.c:3823 do_sys_openat2+0x12c/0x170 fs/open.c:1422 do_sys_open fs/open.c:1437 [inline] __do_sys_openat fs/open.c:1453 [inline] __se_sys_openat fs/open.c:1448 [inline] __x64_sys_openat+0x134/0x1d0 fs/open.c:1448 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 page_owner free stack trace missing Memory state around the buggy address: ffff88811c01f880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811c01f900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88811c01f980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811c01fa00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811c01fa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================