================================================================== BUG: KASAN: use-after-free in pick_link+0x567/0xe30 fs/namei.c:1799 Read of size 8 at addr ffff88813332d2d0 by task syz.3.553/2526 CPU: 1 PID: 2526 Comm: syz.3.553 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:351 pick_link+0x567/0xe30 fs/namei.c:1799 step_into+0xc5c/0xf40 fs/namei.c:1875 walk_component fs/namei.c:2011 [inline] link_path_walk+0x6c1/0xe80 fs/namei.c:2332 path_parentat fs/namei.c:2533 [inline] __filename_parentat+0x226/0x650 fs/namei.c:2557 filename_parentat fs/namei.c:2575 [inline] do_unlinkat+0xeb/0x6d0 fs/namei.c:4368 __do_sys_unlinkat fs/namei.c:4440 [inline] __se_sys_unlinkat fs/namei.c:4433 [inline] __x64_sys_unlinkat+0xd8/0xf0 fs/namei.c:4433 x64_sys_call+0x79f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:264 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4adcf9c629 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4adddf1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 00007f4add216180 RCX: 00007f4adcf9c629 RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000000000000008 RBP: 00007f4add032b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4add216218 R14: 00007f4add216180 R15: 00007ffddbbc6208 Allocated by task 2523: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:334 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768 slab_alloc_node mm/slub.c:3382 [inline] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc_lru+0x104/0x280 mm/slub.c:3415 alloc_inode_sb include/linux/fs.h:3263 [inline] alloc_inode fs/inode.c:266 [inline] new_inode_pseudo+0x8f/0x1f0 fs/inode.c:1073 new_inode+0x28/0x1e0 fs/inode.c:1101 bpf_get_inode kernel/bpf/inode.c:116 [inline] bpf_symlink+0x65/0x270 kernel/bpf/inode.c:394 vfs_symlink+0x261/0x3f0 fs/namei.c:4478 do_symlinkat+0x124/0x5a0 fs/namei.c:4507 __do_sys_symlinkat fs/namei.c:4524 [inline] __se_sys_symlinkat fs/namei.c:4521 [inline] __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4521 x64_sys_call+0x282/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:267 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 2523: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:250 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1750 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776 slab_free mm/slub.c:3712 [inline] kmem_cache_free+0x12d/0x300 mm/slub.c:3737 free_inode_nonrcu+0x1c/0x20 fs/inode.c:245 bpf_destroy_inode+0x14a/0x170 kernel/bpf/inode.c:621 destroy_inode fs/inode.c:314 [inline] evict+0x7d0/0x8f0 fs/inode.c:723 iput_final fs/inode.c:1844 [inline] iput+0x620/0x670 fs/inode.c:1870 do_unlinkat+0x380/0x6d0 fs/namei.c:4404 __do_sys_unlinkat fs/namei.c:4440 [inline] __se_sys_unlinkat fs/namei.c:4433 [inline] __x64_sys_unlinkat+0xd8/0xf0 fs/namei.c:4433 x64_sys_call+0x79f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:264 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 __call_rcu_common kernel/rcu/tree.c:2807 [inline] call_rcu+0xcf/0xf90 kernel/rcu/tree.c:2926 destroy_inode fs/inode.c:319 [inline] evict+0x850/0x8f0 fs/inode.c:723 iput_final fs/inode.c:1844 [inline] iput+0x620/0x670 fs/inode.c:1870 dentry_unlink_inode+0x33d/0x3f0 fs/dcache.c:405 __dentry_kill+0x460/0x670 fs/dcache.c:611 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x42/0x80 fs/dcache.c:918 find_next_child fs/libfs.c:265 [inline] simple_recursive_removal+0x273/0x820 fs/libfs.c:280 debugfs_remove+0x56/0x70 fs/debugfs/inode.c:778 kvm_destroy_vm_debugfs virt/kvm/kvm_main.c:1035 [inline] kvm_destroy_vm virt/kvm/kvm_main.c:1305 [inline] kvm_put_kvm+0x12c/0x1450 virt/kvm/kvm_main.c:1370 kvm_vm_release+0x46/0x50 virt/kvm/kvm_main.c:1393 __fput+0x1fc/0x8f0 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1e1/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 __call_rcu_common kernel/rcu/tree.c:2807 [inline] call_rcu+0xcf/0xf90 kernel/rcu/tree.c:2926 destroy_inode fs/inode.c:319 [inline] evict+0x850/0x8f0 fs/inode.c:723 iput_final fs/inode.c:1844 [inline] iput+0x620/0x670 fs/inode.c:1870 dentry_unlink_inode+0x33d/0x3f0 fs/dcache.c:405 __dentry_kill+0x460/0x670 fs/dcache.c:611 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x42/0x80 fs/dcache.c:918 find_next_child fs/libfs.c:265 [inline] simple_recursive_removal+0x273/0x820 fs/libfs.c:280 debugfs_remove+0x56/0x70 fs/debugfs/inode.c:778 kvm_destroy_vm_debugfs virt/kvm/kvm_main.c:1035 [inline] kvm_destroy_vm virt/kvm/kvm_main.c:1305 [inline] kvm_put_kvm+0x12c/0x1450 virt/kvm/kvm_main.c:1370 kvm_vm_release+0x46/0x50 virt/kvm/kvm_main.c:1393 __fput+0x1fc/0x8f0 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1e1/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88813332d040 which belongs to the cache inode_cache of size 704 The buggy address is located 656 bytes inside of 704-byte region [ffff88813332d040, ffff88813332d300) The buggy address belongs to the physical page: page:ffffea0004cccb00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13332c head:ffffea0004cccb00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 ffffea0004fa0b00 dead000000000003 ffff8881001ec300 raw: 0000000000000000 0000000080130013 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Reclaimable, gfp_mask 0x1d20d0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 1284, tgid 1283 (syz.0.237), ts 61259595242, free_ts 61043653306 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643 prep_new_page+0x1c/0x110 mm/page_alloc.c:2650 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4554 __alloc_pages+0x1d9/0x480 mm/page_alloc.c:5868 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3d0 mm/slub.c:2020 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc_lru+0x144/0x280 mm/slub.c:3415 alloc_inode_sb include/linux/fs.h:3263 [inline] alloc_inode fs/inode.c:266 [inline] new_inode_pseudo+0x8f/0x1f0 fs/inode.c:1073 new_inode+0x28/0x1e0 fs/inode.c:1101 debugfs_get_inode fs/debugfs/inode.c:72 [inline] __debugfs_create_file+0x14e/0x510 fs/debugfs/inode.c:432 debugfs_create_file+0x4a/0x60 fs/debugfs/inode.c:489 kvm_create_vm_debugfs+0x484/0x980 virt/kvm/kvm_main.c:1089 kvm_create_vm virt/kvm/kvm_main.c:1239 [inline] kvm_dev_ioctl_create_vm virt/kvm/kvm_main.c:5010 [inline] kvm_dev_ioctl+0xe37/0x11f0 virt/kvm/kvm_main.c:5052 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1551 [inline] free_pcp_prepare mm/page_alloc.c:1625 [inline] free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3589 free_unref_page+0x95/0x540 mm/page_alloc.c:3687 free_the_page mm/page_alloc.c:836 [inline] __free_pages+0x67/0x100 mm/page_alloc.c:5957 __free_slab+0xca/0x1a0 mm/slub.c:2044 free_slab mm/slub.c:2059 [inline] discard_slab+0x29/0x40 mm/slub.c:2065 __slab_free+0x201/0x280 mm/slub.c:3625 do_slab_free mm/slub.c:3666 [inline] ___cache_free+0xbf/0xd0 mm/slub.c:3722 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0xc6/0x140 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:311 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768 slab_alloc_node mm/slub.c:3382 [inline] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc+0x16e/0x330 mm/slub.c:3408 getname_flags+0xb9/0x500 fs/namei.c:139 user_path_at_empty+0x30/0x1c0 fs/namei.c:2911 do_readlinkat+0xd9/0x490 fs/stat.c:468 __do_sys_readlink fs/stat.c:501 [inline] __se_sys_readlink fs/stat.c:498 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:498 Memory state around the buggy address: ffff88813332d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88813332d200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88813332d280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88813332d300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88813332d380: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================