svc: failed to register nfsdv3 RPC service (errno 101). svc: failed to register nfsaclv3 RPC service (errno 101). ================================================================== BUG: KASAN: use-after-free in nfsd_svc+0x996/0xab0 fs/nfsd/nfssvc.c:813 Read of size 4 at addr ffff888056da5854 by task syz.4.123/4700 CPU: 0 PID: 4700 Comm: syz.4.123 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 nfsd_svc+0x996/0xab0 fs/nfsd/nfssvc.c:813 write_threads+0x2ea/0x350 fs/nfsd/nfsctl.c:424 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114 vfs_write+0x2dc/0x9a0 fs/read_write.c:582 ksys_write+0x14d/0x260 fs/read_write.c:637 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: 0033:0x7fd04879e019 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:00007fd0495c0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fd048a25fa0 RCX: 00007fd04879e019 RDX: 0000000000000002 RSI: 0000200000000280 RDI: 0000000000000005 RBP: 00007fd04883500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd048a26038 R14: 00007fd048a25fa0 R15: 00007fffce6a06f8 Allocated by task 4700: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] __svc_create+0x60/0x9d0 net/sunrpc/svc.c:464 svc_create_pooled+0x71f/0x8c0 net/sunrpc/svc.c:552 nfsd_create_serv+0x2f9/0x700 fs/nfsd/nfssvc.c:667 nfsd_svc+0x17f/0xab0 fs/nfsd/nfssvc.c:796 write_threads+0x2ea/0x350 fs/nfsd/nfsctl.c:424 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114 vfs_write+0x2dc/0x9a0 fs/read_write.c:582 ksys_write+0x14d/0x260 fs/read_write.c:637 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 4700: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x200 mm/slub.c:3700 kref_put include/linux/kref.h:65 [inline] svc_put include/linux/sunrpc/svc.h:123 [inline] nfsd_svc+0x75e/0xab0 fs/nfsd/nfssvc.c:811 write_threads+0x2ea/0x350 fs/nfsd/nfsctl.c:424 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114 vfs_write+0x2dc/0x9a0 fs/read_write.c:582 ksys_write+0x14d/0x260 fs/read_write.c:637 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 The buggy address belongs to the object at ffff888056da5800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 84 bytes inside of 512-byte region [ffff888056da5800, ffff888056da5a00) The buggy address belongs to the physical page: page:ffffea00015b6900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x56da4 head:ffffea00015b6900 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea00015cd200 dead000000000002 ffff888017441c80 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 4273, tgid 4273 (syz-executor), ts 75251093584, free_ts 75250771988 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560 prep_new_page mm/page_alloc.c:2567 [inline] get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658 alloc_slab_page+0x5d/0x180 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2d0 mm/slub.c:1997 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] mca_alloc net/ipv6/mcast.c:887 [inline] __ipv6_dev_mc_inc+0x47b/0xb20 net/ipv6/mcast.c:942 ipv6_add_dev+0xce3/0x1110 net/ipv6/addrconf.c:466 addrconf_notify+0x634/0xf60 net/ipv6/addrconf.c:3602 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] register_netdevice+0x16a8/0x1b80 net/core/dev.c:10276 macsec_newlink+0x6ba/0x1120 drivers/net/macsec.c:4119 rtnl_newlink_create net/core/rtnetlink.c:3436 [inline] __rtnl_newlink net/core/rtnetlink.c:3656 [inline] rtnl_newlink+0x14b3/0x1f90 net/core/rtnetlink.c:3669 rtnetlink_rcv_msg+0x863/0xfb0 net/core/rtnetlink.c:6166 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1487 [inline] free_pcp_prepare mm/page_alloc.c:1537 [inline] free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509 __stack_depot_save+0x44d/0x480 lib/stackdepot.c:506 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_set_track+0x60/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x490 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc+0x18b/0x2f0 mm/slub.c:3383 kmem_cache_zalloc include/linux/slab.h:689 [inline] fill_pool lib/debugobjects.c:169 [inline] debug_objects_fill_pool+0x57a/0x780 lib/debugobjects.c:654 __debug_object_init+0x27/0x440 lib/debugobjects.c:666 ipv6_mc_init_dev+0x44/0x7c0 net/ipv6/mcast.c:2805 ipv6_add_dev+0xb4b/0x1110 net/ipv6/addrconf.c:448 addrconf_notify+0x634/0xf60 net/ipv6/addrconf.c:3602 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] register_netdevice+0x16a8/0x1b80 net/core/dev.c:10276 macsec_newlink+0x6ba/0x1120 drivers/net/macsec.c:4119 rtnl_newlink_create net/core/rtnetlink.c:3436 [inline] __rtnl_newlink net/core/rtnetlink.c:3656 [inline] rtnl_newlink+0x14b3/0x1f90 net/core/rtnetlink.c:3669 Memory state around the buggy address: ffff888056da5700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888056da5780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888056da5800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888056da5880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888056da5900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================