[EXT4 FS bs=1024, gc=1, bpg=131072, ipg=32, mo=e855c01c, mo2=0003]
System zones: 0-1, 3-36
EXT4-fs (loop0): mounted filesystem without journal. Opts: grpquota,delalloc,resuid=0x0000000000000000,debug,dioread_nolock,bsddf,nomblk_io_submit,noauto_da_alloc,,errors=continue
==================================================================
BUG: KASAN: use-after-free in ext4_get_inode_usage+0x3a1/0x520 fs/ext4/xattr.c:817
Read of size 4 at addr ffff888124c2e070 by task syz.0.2043/7351

CPU: 1 PID: 7351 Comm: syz.0.2043 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0xe2/0x130 mm/kasan/report.c:452
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 ext4_get_inode_usage+0x3a1/0x520 fs/ext4/xattr.c:817
 __dquot_transfer+0x192/0x20d0 fs/quota/dquot.c:2017
 dquot_transfer+0x2f1/0x460 fs/quota/dquot.c:2169
 ext4_setattr+0x715/0x1950 fs/ext4/inode.c:5577
 notify_change+0xab3/0xe40 fs/attr.c:410
 chown_common+0x335/0x500 fs/open.c:675
 vfs_fchown fs/open.c:742 [inline]
 ksys_fchown+0xef/0x160 fs/open.c:753
 __do_sys_fchown fs/open.c:761 [inline]
 __se_sys_fchown fs/open.c:759 [inline]
 __x64_sys_fchown+0x7a/0x90 fs/open.c:759
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f54054e5e59
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:00007f5403f40028 EFLAGS: 00000246 ORIG_RAX: 000000000000005d
RAX: ffffffffffffffda RBX: 00007f540575efa0 RCX: 00007f54054e5e59
RDX: 000000000000ee01 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f540557bd6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f540575f038 R14: 00007f540575efa0 R15: 00007ffffd5efd28

Allocated by task 7033:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:430 [inline]
 __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:463
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580
 slab_alloc_node mm/slub.c:2952 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 kmem_cache_alloc+0x162/0x2d0 mm/slub.c:2965
 kmem_cache_zalloc include/linux/slab.h:657 [inline]
 __proc_create+0x378/0x8e0 fs/proc/generic.c:431
 proc_create_reg+0x96/0x110 fs/proc/generic.c:558
 proc_create_net_data+0x95/0x1a0 fs/proc/proc_net.c:110
 igmp_net_init+0x61/0x160 net/ipv4/igmp.c:3025
 ops_init+0x1ba/0x4a0 net/core/net_namespace.c:144
 setup_net+0x376/0xb60 net/core/net_namespace.c:345
 copy_net_ns+0x314/0x520 net/core/net_namespace.c:486
 create_new_namespaces+0x3a2/0x650 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:231
 ksys_unshare+0x50f/0x800 kernel/fork.c:3156
 __do_sys_unshare kernel/fork.c:3224 [inline]
 __se_sys_unshare kernel/fork.c:3222 [inline]
 __x64_sys_unshare+0x38/0x40 kernel/fork.c:3222
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 7:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1600 [inline]
 slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626
 slab_free mm/slub.c:3208 [inline]
 kmem_cache_free+0x100/0x2d0 mm/slub.c:3224
 pde_free fs/proc/generic.c:43 [inline]
 pde_put+0x14e/0x1a0 fs/proc/generic.c:692
 remove_proc_entry+0x35a/0x4c0 fs/proc/generic.c:740
 igmp_net_exit+0x6b/0xd0 net/ipv4/igmp.c:3054
 ops_exit_list net/core/net_namespace.c:185 [inline]
 cleanup_net+0x58e/0xb80 net/core/net_namespace.c:609
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

The buggy address belongs to the object at ffff888124c2e000
 which belongs to the cache proc_dir_entry of size 192
The buggy address is located 112 bytes inside of
 192-byte region [ffff888124c2e000, ffff888124c2e0c0)
The buggy address belongs to the page:
page:ffffea0004930b80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x124c2e
flags: 0x4000000000000200(slab)
raw: 4000000000000200 dead000000000100 dead000000000122 ffff88810018b080
raw: 0000000000000000 0000000000100010 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 3742, ts 158492898874, free_ts 158117918079
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x179/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x223b/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x290/0x620 mm/page_alloc.c:5384
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1813 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1874
 new_slab_objects mm/slub.c:2632 [inline]
 ___slab_alloc+0x2a6/0x450 mm/slub.c:2796
 __slab_alloc+0x63/0xa0 mm/slub.c:2836
 slab_alloc_node mm/slub.c:2918 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 kmem_cache_alloc+0x1ac/0x2d0 mm/slub.c:2965
 kmem_cache_zalloc include/linux/slab.h:657 [inline]
 __proc_create+0x378/0x8e0 fs/proc/generic.c:431
 proc_create_reg+0x96/0x110 fs/proc/generic.c:558
 proc_create_net_data+0x95/0x1a0 fs/proc/proc_net.c:110
 vlan_proc_init+0x11d/0x2d0 net/8021q/vlanproc.c:119
 vlan_init_net+0x8d/0xb0 net/8021q/vlan.c:665
 ops_init+0x1ba/0x4a0 net/core/net_namespace.c:144
 setup_net+0x376/0xb60 net/core/net_namespace.c:345
 copy_net_ns+0x314/0x520 net/core/net_namespace.c:486
 create_new_namespaces+0x3a2/0x650 kernel/nsproxy.c:110
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336
 free_unref_page mm/page_alloc.c:3391 [inline]
 free_the_page mm/page_alloc.c:5443 [inline]
 __free_pages+0x146/0x3b0 mm/page_alloc.c:5454
 __vunmap+0x86d/0x9f0 mm/vmalloc.c:2307
 free_work+0x5a/0x80 mm/vmalloc.c:69
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Memory state around the buggy address:
 ffff888124c2df00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888124c2df80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888124c2e000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff888124c2e080: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888124c2e100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
EXT4-fs error (device loop0): __ext4_get_inode_loc:4451: comm syz.0.2043: Invalid inode table block 18383322559214291671 in block_group 0