loop4: detected capacity change from 0 to 1024 EXT4-fs (loop4): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. ================================================================== BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x94b/0x1e90 fs/ext4/xattr.c:1783 Read of size 18446744073709551588 at addr ffff88807f718840 by task syz.4.1025/9620 CPU: 0 PID: 9620 Comm: syz.4.1025 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 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 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x241/0x290 mm/kasan/generic.c:187 __asan_memmove+0x29/0x70 mm/kasan/shadow.c:94 ext4_xattr_set_entry+0x94b/0x1e90 fs/ext4/xattr.c:1783 ext4_xattr_block_set+0xae8/0x32b0 fs/ext4/xattr.c:2030 ext4_xattr_set_handle+0x1280/0x14c0 fs/ext4/xattr.c:2452 ext4_xattr_set+0x252/0x340 fs/ext4/xattr.c:2554 __vfs_setxattr+0x431/0x470 fs/xattr.c:201 __vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235 vfs_setxattr+0x16b/0x2f0 fs/xattr.c:322 do_setxattr fs/xattr.c:630 [inline] path_setxattr+0x3f3/0x5d0 fs/xattr.c:659 __do_sys_lsetxattr fs/xattr.c:684 [inline] __se_sys_lsetxattr fs/xattr.c:680 [inline] __x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fe13059aeb9 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:00007fe131532028 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd RAX: ffffffffffffffda RBX: 00007fe130815fa0 RCX: 00007fe13059aeb9 RDX: 0000200000000000 RSI: 0000200000000180 RDI: 00002000000001c0 RBP: 00007fe130608c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000361 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe130816038 R14: 00007fe130815fa0 R15: 00007ffd58e40a18 Allocated by task 9620: 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 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027 kmemdup+0x2b/0x70 mm/util.c:131 kmemdup include/linux/fortify-string.h:779 [inline] ext4_xattr_block_set+0x9ea/0x32b0 fs/ext4/xattr.c:1978 ext4_xattr_set_handle+0x1280/0x14c0 fs/ext4/xattr.c:2452 ext4_xattr_set+0x252/0x340 fs/ext4/xattr.c:2554 __vfs_setxattr+0x431/0x470 fs/xattr.c:201 __vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235 vfs_setxattr+0x16b/0x2f0 fs/xattr.c:322 do_setxattr fs/xattr.c:630 [inline] path_setxattr+0x3f3/0x5d0 fs/xattr.c:659 __do_sys_lsetxattr fs/xattr.c:684 [inline] __se_sys_lsetxattr fs/xattr.c:680 [inline] __x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 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 kvfree_call_rcu+0xee/0x790 kernel/rcu/tree.c:3452 cgroup_migrate_finish+0x1a3/0x370 kernel/cgroup/cgroup.c:2692 cgroup_attach_task+0x655/0x8e0 kernel/cgroup/cgroup.c:2891 cgroup_attach_task_all+0x9a/0xe0 kernel/cgroup/cgroup-v1.c:70 kvm_vm_worker_thread+0x38e/0x570 virt/kvm/kvm_main.c:6234 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 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 kvfree_call_rcu+0xee/0x790 kernel/rcu/tree.c:3452 neigh_del net/core/neighbour.c:226 [inline] neigh_remove_one+0x5f1/0x700 net/core/neighbour.c:247 neigh_forced_gc net/core/neighbour.c:280 [inline] neigh_alloc net/core/neighbour.c:486 [inline] ___neigh_create+0x467/0x2440 net/core/neighbour.c:649 ip6_finish_output2+0x1581/0x1630 net/ipv6/ip6_output.c:132 dst_output include/net/dst.h:467 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ndisc_send_skb+0xc26/0x14f0 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x2d5/0x630 net/ipv6/addrconf.c:4024 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 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 ffff88807f718800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 64 bytes inside of 1024-byte region [ffff88807f718800, ffff88807f718c00) The buggy address belongs to the physical page: page:ffffea0001fdc600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7f718 head:ffffea0001fdc600 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017c41dc0 ffffea0000c44800 dead000000000002 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 2966, tgid 2966 (kworker/u4:11), ts 80308018741, free_ts 80196178811 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581 prep_new_page mm/page_alloc.c:1588 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4486 alloc_slab_page+0x5d/0x160 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5d/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+0x19e/0x250 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0xa4/0x230 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:721 [inline] neigh_alloc net/core/neighbour.c:495 [inline] ___neigh_create+0x6d2/0x2440 net/core/neighbour.c:649 ip6_finish_output2+0x1581/0x1630 net/ipv6/ip6_output.c:132 dst_output include/net/dst.h:467 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ndisc_send_skb+0xc26/0x14f0 net/ipv6/ndisc.c:513 ndisc_send_ns+0xd8/0x160 net/ipv6/ndisc.c:671 addrconf_dad_work+0xa51/0x1530 net/ipv6/addrconf.c:4264 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519 vm_area_alloc+0x24/0x1d0 kernel/fork.c:486 __mmap_region mm/mmap.c:2770 [inline] mmap_region+0xc2f/0x2000 mm/mmap.c:2941 do_mmap+0x92c/0x10a0 mm/mmap.c:1385 vm_mmap_pgoff+0x1c4/0x3f0 mm/util.c:556 ksys_mmap_pgoff+0x520/0x700 mm/mmap.c:1431 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 Memory state around the buggy address: ffff88807f718700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807f718780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807f718800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff88807f718880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807f718900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================