svc: failed to register nfsdv3 RPC service (errno 111). svc: failed to register nfsaclv3 RPC service (errno 111). ================================================================== BUG: KASAN: slab-use-after-free in nfsd_svc+0x99a/0xab0 fs/nfsd/nfssvc.c:818 Read of size 4 at addr ffff88801bb17454 by task syz.4.2320/15923 CPU: 0 PID: 15923 Comm: syz.4.2320 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 nfsd_svc+0x99a/0xab0 fs/nfsd/nfssvc.c:818 write_threads+0x393/0x510 fs/nfsd/nfsctl.c:417 nfsctl_transaction_write+0x10c/0x150 fs/nfsd/nfsctl.c:113 vfs_write+0x299/0x9a0 fs/read_write.c:582 ksys_write+0x151/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4f6c39e159 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:00007f4f6d1bf028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f4f6c625fa0 RCX: 00007f4f6c39e159 RDX: 0000000000000001 RSI: 00002000000001c0 RDI: 0000000000000003 RBP: 00007f4f6c43506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4f6c626038 R14: 00007f4f6c625fa0 R15: 00007ffcf38ab6d8 Allocated by task 15923: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] __svc_create+0x60/0xbb0 net/sunrpc/svc.c:520 svc_create_pooled+0x66a/0x7e0 net/sunrpc/svc.c:618 nfsd_create_serv+0x29f/0x5c0 fs/nfsd/nfssvc.c:672 nfsd_svc+0x183/0xab0 fs/nfsd/nfssvc.c:801 write_threads+0x393/0x510 fs/nfsd/nfsctl.c:417 nfsctl_transaction_write+0x10c/0x150 fs/nfsd/nfsctl.c:113 vfs_write+0x299/0x9a0 fs/read_write.c:582 ksys_write+0x151/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 15923: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843 kref_put include/linux/kref.h:65 [inline] svc_put include/linux/sunrpc/svc.h:124 [inline] nfsd_svc+0x762/0xab0 fs/nfsd/nfssvc.c:816 write_threads+0x393/0x510 fs/nfsd/nfsctl.c:417 nfsctl_transaction_write+0x10c/0x150 fs/nfsd/nfsctl.c:113 vfs_write+0x299/0x9a0 fs/read_write.c:582 ksys_write+0x151/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x153/0x900 kernel/rcu/tree.c:2837 __key_link+0x14a/0x320 security/keys/keyring.c:1378 __key_instantiate_and_link+0x353/0x4c0 security/keys/key.c:460 __key_create_or_update+0x87a/0xa60 security/keys/key.c:926 key_create_or_update+0x42/0x60 security/keys/key.c:1007 __do_sys_add_key security/keys/keyctl.c:134 [inline] __se_sys_add_key+0x34f/0x410 security/keys/keyctl.c:74 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 insert_work+0x3d/0x310 kernel/workqueue.c:1674 __queue_work+0xcf4/0xfd0 kernel/workqueue.c:1827 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1747 [inline] __run_timers+0x59c/0x810 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x27d/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 The buggy address belongs to the object at ffff88801bb17400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 84 bytes inside of freed 512-byte region [ffff88801bb17400, ffff88801bb17600) The buggy address belongs to the physical page: page:ffffea00006ec500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1bb14 head:ffffea00006ec500 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017c41c80 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000100010 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 200, tgid 200 (kworker/u4:3), ts 6167408720, free_ts 6156067273 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582 prep_new_page mm/page_alloc.c:1589 [inline] get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501 alloc_slab_page+0x5d/0x180 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5c/0x12f0 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x11f/0x250 mm/slub.c:3534 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] alloc_bprm+0x56/0x9a0 fs/exec.c:1538 kernel_execve+0x98/0x980 fs/exec.c:2023 call_usermodehelper_exec_async+0x20b/0x350 kernel/umh.c:110 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1182 [inline] free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459 __stack_depot_save+0x587/0x660 lib/stackdepot.c:443 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_set_track+0x5f/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc_node_track_caller+0xb4/0x230 mm/slab_common.c:1027 kstrdup+0x3b/0x80 mm/util.c:62 __kernfs_new_node+0xaa/0x7f0 fs/kernfs/dir.c:620 kernfs_new_node+0x14c/0x260 fs/kernfs/dir.c:700 kernfs_create_link+0xa7/0x200 fs/kernfs/symlink.c:39 sysfs_do_create_link_sd+0x83/0x110 fs/sysfs/symlink.c:44 device_create_sys_dev_entry+0x123/0x180 drivers/base/core.c:3511 device_add+0x7c3/0xc40 drivers/base/core.c:3655 tty_register_device_attr+0x428/0x990 drivers/tty/tty_io.c:3253 tty_register_device drivers/tty/tty_io.c:3188 [inline] tty_register_driver+0x5d8/0xb70 drivers/tty/tty_io.c:3451 legacy_pty_init+0x3a6/0x600 drivers/tty/pty.c:579 Memory state around the buggy address: ffff88801bb17300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801bb17380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801bb17400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801bb17480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801bb17500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__G[ 1116.125476][ T5128] EXT4-fs warning (device sda1): ext4_dirblock_csum_verify:406: inode #2001: comm syslogd: No space for directory leaf checksum. Please run e2fsck -D. page last free stack trace: