==================================================================
BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xbe3/0xbf0 fs/ext4/xattr.c:2909
Read of size 4 at addr ffff88812425a000 by task syz-executor/480

CPU: 1 PID: 480 Comm: syz-executor Not tainted 5.10.240-syzkaller-1008085-g1154f779f3f3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x169/0x1d8 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_xattr_delete_inode+0xbe3/0xbf0 fs/ext4/xattr.c:2909
 ext4_evict_inode+0x106f/0x16e0 fs/ext4/inode.c:300
 evict+0x478/0x910 fs/inode.c:612
 iput_final fs/inode.c:1736 [inline]
 iput+0x638/0x7c0 fs/inode.c:1762
 d_delete_notify include/linux/fsnotify.h:267 [inline]
 vfs_rmdir+0x2bd/0x3e0 fs/namei.c:3865
 do_rmdir+0x218/0x620 fs/namei.c:3912
 __do_sys_unlinkat fs/namei.c:4076 [inline]
 __se_sys_unlinkat fs/namei.c:4070 [inline]
 __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4070
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f7318de7707
Code: 73 01 c3 48 c7 c1 b0 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdf4ddfb28 EFLAGS: 00000207 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f7318de7707
RDX: 0000000000000200 RSI: 00007ffdf4de0cd0 RDI: 00000000ffffff9c
RBP: 00007f7318e446c6 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffdf4de0cd0
R13: 00007f7318e446c6 R14: 000000000000c0ea R15: 0000000000000006

Allocated by task 436:
 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:583
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x165/0x2e0 mm/slub.c:2960
 kmem_cache_alloc_node include/linux/slab.h:423 [inline]
 __alloc_skb+0x9e/0x520 net/core/skbuff.c:200
 alloc_skb include/linux/skbuff.h:1126 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1178 [inline]
 netlink_sendmsg+0x5f6/0xb30 net/netlink/af_netlink.c:1889
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430
 __sys_sendmsg net/socket.c:2459 [inline]
 __do_sys_sendmsg net/socket.c:2468 [inline]
 __se_sys_sendmsg net/socket.c:2466 [inline]
 __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 436:
 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:1595 [inline]
 slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1621
 slab_free mm/slub.c:3203 [inline]
 kmem_cache_free+0x100/0x2d0 mm/slub.c:3219
 kfree_skbmem+0x10c/0x180 net/core/skbuff.c:-1
 __kfree_skb net/core/skbuff.c:695 [inline]
 consume_skb+0xb3/0x1f0 net/core/skbuff.c:851
 netlink_unicast_kernel net/netlink/af_netlink.c:1315 [inline]
 netlink_unicast+0x87e/0xa40 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1914
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430
 __sys_sendmsg net/socket.c:2459 [inline]
 __do_sys_sendmsg net/socket.c:2468 [inline]
 __se_sys_sendmsg net/socket.c:2466 [inline]
 __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff88812425a000
 which belongs to the cache skbuff_head_cache of size 248
The buggy address is located 0 bytes inside of
 248-byte region [ffff88812425a000, ffff88812425a0f8)
The buggy address belongs to the page:
page:ffffea0004909680 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12425a
flags: 0x4000000000000200(slab)
raw: 4000000000000200 dead000000000100 dead000000000122 ffff888107d94900
raw: 0000000000000000 00000000000c000c 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 9, ts 49462113306, free_ts 49216623048
 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+0x2235/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5357
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x2a6/0x450 mm/slub.c:2791
 __slab_alloc+0x63/0xa0 mm/slub.c:2831
 slab_alloc_node mm/slub.c:2913 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x1af/0x2e0 mm/slub.c:2960
 kmem_cache_alloc_node include/linux/slab.h:423 [inline]
 __alloc_skb+0x9e/0x520 net/core/skbuff.c:200
 alloc_skb include/linux/skbuff.h:1126 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 inet6_netconf_notify_devconf+0xd6/0x190 net/ipv6/addrconf.c:579
 __addrconf_sysctl_unregister net/ipv6/addrconf.c:7095 [inline]
 addrconf_sysctl_unregister net/ipv6/addrconf.c:7119 [inline]
 addrconf_ifdown+0x1545/0x1800 net/ipv6/addrconf.c:3940
 addrconf_notify+0x3bd/0xe90 net/ipv6/addrconf.c:-1
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410
 call_netdevice_notifiers_info net/core/dev.c:2054 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2066 [inline]
 call_netdevice_notifiers net/core/dev.c:2080 [inline]
 unregister_netdevice_many+0xf8b/0x1980 net/core/dev.c:10767
 ip_tunnel_delete_nets+0x343/0x390 net/ipv4/ip_tunnel.c:1136
 ipgre_tap_exit_batch_net+0x22/0x30 net/ipv4/ip_gre.c:1706
 ops_exit_list net/core/net_namespace.c:190 [inline]
 cleanup_net+0x5fb/0xb70 net/core/net_namespace.c:609
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_list+0x12e/0x9b0 mm/page_alloc.c:3443
 release_pages+0xe38/0xe80 mm/swap.c:1103
 __pagevec_release+0x71/0xe0 mm/swap.c:1123
 pagevec_release include/linux/pagevec.h:88 [inline]
 __invalidate_mapping_pages+0x887/0x920 mm/truncate.c:607
 invalidate_mapping_pages+0x27/0x30 mm/truncate.c:632
 invalidate_bdev+0xa3/0x140 fs/block_dev.c:97
 ext4_put_super+0x669/0x9c0 fs/ext4/super.c:1237
 generic_shutdown_super+0x149/0x320 fs/super.c:465
 kill_block_super+0x7f/0xf0 fs/super.c:1469
 deactivate_locked_super+0xa0/0x100 fs/super.c:335
 deactivate_super+0xaf/0xe0 fs/super.c:366
 cleanup_mnt+0x446/0x500 fs/namespace.c:1114
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1121
 task_work_run+0x127/0x190 kernel/task_work.c:189
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172

Memory state around the buggy address:
 ffff888124259f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888124259f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88812425a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88812425a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
 ffff88812425a100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
==================================================================