================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2913 Read of size 4 at addr ffff88810a69d000 by task syz-executor/466 CPU: 1 PID: 466 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 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_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350 ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2913 ext4_evict_inode+0xe58/0x1460 fs/ext4/inode.c:296 evict+0x493/0x890 fs/inode.c:705 iput_final fs/inode.c:1834 [inline] iput+0x620/0x670 fs/inode.c:1860 d_delete_notify include/linux/fsnotify.h:292 [inline] vfs_rmdir+0x3bf/0x500 fs/namei.c:4203 do_rmdir+0x259/0x6a0 fs/namei.c:4251 __do_sys_unlinkat fs/namei.c:4431 [inline] __se_sys_unlinkat fs/namei.c:4425 [inline] __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4425 x64_sys_call+0x79f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:264 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f69d6f79497 Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 07 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc336c2bd8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f69d6f79497 RDX: 0000000000000200 RSI: 00007ffc336c3d80 RDI: 00000000ffffff9c RBP: 00007f69d6fe77dc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffc336c3d80 R13: 00007f69d6fe77dc R14: 000000000000b78e R15: 00007ffc336c5f30 Allocated by task 520: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:333 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 vm_area_dup+0x27/0x280 kernel/fork.c:511 __split_vma+0x1d2/0x930 mm/mmap.c:2439 do_mas_align_munmap+0x2e1/0x1230 mm/mmap.c:2565 do_mas_munmap+0x241/0x2b0 mm/mmap.c:2749 __vm_munmap+0x19f/0x2f0 mm/mmap.c:3048 __do_sys_munmap mm/mmap.c:3074 [inline] __se_sys_munmap mm/mmap.c:3070 [inline] __x64_sys_munmap+0x6b/0x80 mm/mmap.c:3070 x64_sys_call+0x8a/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:12 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 13: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 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 __vm_area_free+0x7e/0x130 kernel/fork.c:537 vm_area_free_rcu_cb+0x15/0x20 kernel/fork.c:548 rcu_do_batch+0x515/0xb90 kernel/rcu/tree.c:2297 rcu_core+0x5a5/0xe70 kernel/rcu/tree.c:2557 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2574 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642 run_ksoftirqd+0x28/0x30 kernel/softirq.c:1019 smpboot_thread_fn+0x4a0/0x910 kernel/smpboot.c:164 kthread+0x281/0x320 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __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+0xd4/0xf90 kernel/rcu/tree.c:2926 vm_area_free+0x1c/0x20 kernel/fork.c:555 remove_vma mm/mmap.c:155 [inline] remove_mt mm/mmap.c:2392 [inline] do_mas_align_munmap+0xe9e/0x1230 mm/mmap.c:2695 do_mas_munmap+0x241/0x2b0 mm/mmap.c:2749 __vm_munmap+0x19f/0x2f0 mm/mmap.c:3048 __do_sys_munmap mm/mmap.c:3074 [inline] __se_sys_munmap mm/mmap.c:3070 [inline] __x64_sys_munmap+0x6b/0x80 mm/mmap.c:3070 x64_sys_call+0x8a/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:12 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __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+0xd4/0xf90 kernel/rcu/tree.c:2926 vm_area_free+0x1c/0x20 kernel/fork.c:555 remove_vma mm/mmap.c:155 [inline] remove_mt mm/mmap.c:2392 [inline] do_mas_align_munmap+0xe9e/0x1230 mm/mmap.c:2695 do_brk_munmap mm/mmap.c:3185 [inline] __do_sys_brk mm/mmap.c:248 [inline] __se_sys_brk+0x6df/0xa90 mm/mmap.c:181 __x64_sys_brk+0x38/0x40 mm/mmap.c:181 x64_sys_call+0x920/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:13 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88810a69d000 which belongs to the cache vm_area_struct of size 200 The buggy address is located 0 bytes inside of 200-byte region [ffff88810a69d000, ffff88810a69d0c8) The buggy address belongs to the physical page: page:ffffea000429a740 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88810a69db58 pfn:0x10a69d flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea00045349c8 ffffea000425a8c8 ffff8881002abb00 raw: ffff88810a69db58 00000000000f000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 229, tgid 229 (sftp-server), ts 14287564879, free_ts 14286554299 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+0x2c7b/0x2cf0 mm/page_alloc.c:4554 __alloc_pages+0x1c3/0x450 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+0x1b0/0x330 mm/slub.c:3408 vm_area_dup+0x27/0x280 kernel/fork.c:511 __split_vma+0x1d2/0x930 mm/mmap.c:2439 do_mas_align_munmap+0x2e1/0x1230 mm/mmap.c:2565 do_brk_munmap mm/mmap.c:3185 [inline] __do_sys_brk mm/mmap.c:248 [inline] __se_sys_brk+0x6df/0xa90 mm/mmap.c:181 __x64_sys_brk+0x38/0x40 mm/mmap.c:181 x64_sys_call+0x920/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:13 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 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+0x8f/0x530 mm/page_alloc.c:3687 free_the_page+0x13/0x20 mm/page_alloc.c:836 page_frag_free+0x10a/0x120 mm/page_alloc.c:6096 skb_free_frag include/linux/skbuff.h:3283 [inline] skb_free_head net/core/skbuff.c:763 [inline] skb_release_data+0x70f/0x890 net/core/skbuff.c:794 skb_release_all net/core/skbuff.c:859 [inline] __kfree_skb net/core/skbuff.c:873 [inline] kfree_skb_partial+0x6e/0x90 net/core/skbuff.c:5432 tcp_data_queue+0x1f6c/0x6020 net/ipv4/tcp_input.c:5184 tcp_rcv_established+0x97a/0x1a20 net/ipv4/tcp_input.c:6118 tcp_v4_do_rcv+0x446/0xa10 net/ipv4/tcp_ipv4.c:1683 tcp_v4_rcv+0x233c/0x2a80 net/ipv4/tcp_ipv4.c:2114 ip_protocol_deliver_rcu+0x325/0x6e0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x24e/0x410 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:305 [inline] ip_local_deliver+0x1d8/0x320 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:463 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0x773/0x880 net/ipv4/ip_input.c:639 ip_list_rcv+0x3da/0x420 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5640 [inline] __netif_receive_skb_list_core+0x59e/0x770 net/core/dev.c:5688 Memory state around the buggy address: ffff88810a69cf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88810a69cf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88810a69d000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810a69d080: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc ffff88810a69d100: fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== EXT4-fs (loop2): unmounting filesystem. EXT4-fs (loop2): unmounting filesystem. EXT4-fs (loop2): unmounting filesystem. EXT4-fs (loop2): unmounting filesystem. EXT4-fs (loop2): unmounting filesystem.