EXT4-fs (loop2): Warning: mounting with an experimental mount option 'dioread_nolock' for blocksize < PAGE_SIZE
[EXT4 FS bs=1024, gc=1, bpg=131072, ipg=32, mo=e855c01c, mo2=0003]
System zones: 0-1, 3-36
EXT4-fs (loop2): mounted filesystem without journal. Opts: grpquota,delalloc,resuid=0x0000000000000000,debug,dioread_nolock,bsddf,nomblk_io_submit,noauto_da_alloc,,errors=continue. Quota mode: writeback.
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BUG: KASAN: use-after-free in ext4_get_inode_usage+0x39c/0x520 fs/ext4/xattr.c:821
Read of size 4 at addr ffff88811250f070 by task syz.2.21/382

CPU: 0 PID: 382 Comm: syz.2.21 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:427 [inline]
 kasan_report+0x10f/0x150 mm/kasan/report.c:444
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 ext4_get_inode_usage+0x39c/0x520 fs/ext4/xattr.c:821
 __dquot_transfer+0x192/0x22d0 fs/quota/dquot.c:2015
 dquot_transfer+0x2f3/0x470 fs/quota/dquot.c:2167
 ext4_setattr+0x746/0x1b10 fs/ext4/inode.c:5508
 notify_change+0xc30/0xf40 fs/attr.c:505
 chown_common+0x4b4/0x680 fs/open.c:681
 vfs_fchown fs/open.c:749 [inline]
 ksys_fchown+0xef/0x160 fs/open.c:760
 __do_sys_fchown fs/open.c:768 [inline]
 __se_sys_fchown fs/open.c:766 [inline]
 __x64_sys_fchown+0x7a/0x90 fs/open.c:766
 x64_sys_call+0x95f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:94
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7ac4261e59
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:00007ffe5539f8c8 EFLAGS: 00000246 ORIG_RAX: 000000000000005d
RAX: ffffffffffffffda RBX: 00007f7ac44dafa0 RCX: 00007f7ac4261e59
RDX: 000000000000ee01 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f7ac42f7e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7ac44dafac R14: 00007f7ac44dafa0 R15: 00007f7ac44dafa0
 </TASK>

The buggy address belongs to the page:
page:ffffea00044943c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11250f
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea00044942c8 ffffea0004494548 0000000000000000
raw: 0000000000000000 0000000000100000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 112, ts 3892618792, free_ts 32090306115
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2613
 get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487
 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1937 [inline]
 new_slab+0xa0/0x4d0 mm/slub.c:2000
 ___slab_alloc+0x3ac/0x840 mm/slub.c:3033
 __slab_alloc+0x49/0x90 mm/slub.c:3120
 slab_alloc_node mm/slub.c:3211 [inline]
 slab_alloc mm/slub.c:3255 [inline]
 kmem_cache_alloc_trace+0x146/0x270 mm/slub.c:3272
 kmalloc include/linux/slab.h:619 [inline]
 kzalloc include/linux/slab.h:750 [inline]
 kernfs_fop_open+0x375/0xbb0 fs/kernfs/file.c:628
 do_dentry_open+0x82a/0x1010 fs/open.c:828
 vfs_open+0x73/0x80 fs/open.c:960
 do_open fs/namei.c:3616 [inline]
 path_openat+0x26e6/0x2f80 fs/namei.c:3750
 do_filp_open+0x1df/0x400 fs/namei.c:3777
 do_sys_openat2+0x15e/0x7f0 fs/open.c:1236
 do_sys_open fs/open.c:1252 [inline]
 __do_sys_openat fs/open.c:1268 [inline]
 __se_sys_openat fs/open.c:1263 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1263
 x64_sys_call+0x219/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1474 [inline]
 free_pcp_prepare mm/page_alloc.c:1546 [inline]
 free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3536
 free_unref_page+0xae/0x540 mm/page_alloc.c:3618
 free_the_page mm/page_alloc.c:805 [inline]
 __free_pages+0x6c/0x100 mm/page_alloc.c:5900
 __free_slab+0xe5/0x1e0 mm/slub.c:2025
 free_slab mm/slub.c:2040 [inline]
 discard_slab mm/slub.c:2046 [inline]
 __unfreeze_partials+0x15a/0x190 mm/slub.c:2532
 put_cpu_partial+0xc6/0x120 mm/slub.c:2612
 __slab_free+0x1d4/0x290 mm/slub.c:3395
 do_slab_free mm/slub.c:3514 [inline]
 ___cache_free+0x104/0x120 mm/slub.c:3535
 qlink_free+0x4d/0x90 mm/kasan/quarantine.c:157
 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:443
 kasan_slab_alloc include/linux/kasan.h:217 [inline]
 slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550
 slab_alloc_node mm/slub.c:3245 [inline]
 slab_alloc mm/slub.c:3255 [inline]
 kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260
 kmem_cache_alloc_node include/linux/slab.h:492 [inline]
 __alloc_skb+0xe4/0x730 net/core/skbuff.c:416
 alloc_skb include/linux/skbuff.h:1183 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 inet6_netconf_notify_devconf+0xd6/0x190 net/ipv6/addrconf.c:585

Memory state around the buggy address:
 ffff88811250ef00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88811250ef80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88811250f000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                             ^
 ffff88811250f080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88811250f100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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