EXT4-fs (loop1): mounted filesystem without journal. Opts: grpquota,delalloc,resuid=0x0000000000000000,debug,dioread_nolock,block_validity,nomblk_io_submit,noauto_da_alloc,,errors=continue
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BUG: KASAN: use-after-free in ext4_get_inode_usage+0x3a1/0x520 fs/ext4/xattr.c:817
Read of size 4 at addr ffff8881173f2070 by task syz.1.242/1398

CPU: 0 PID: 1398 Comm: syz.1.242 Not tainted 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: 0033:0x7f6b54585e59
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:00007f6b52fe0028 EFLAGS: 00000246 ORIG_RAX: 000000000000005d
RAX: ffffffffffffffda RBX: 00007f6b547fefa0 RCX: 00007f6b54585e59
RDX: 000000000000ee01 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007f6b5461bd6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6b547ff038 R14: 00007f6b547fefa0 R15: 00007ffcad6336f8

Allocated by task 960:
 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_alloc_node include/linux/slab.h:426 [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_rt_notify+0x293/0x480 net/ipv6/route.c:6054
 fib6_add_rt2node net/ipv6/ip6_fib.c:1253 [inline]
 fib6_add+0x217e/0x3c40 net/ipv6/ip6_fib.c:1482
 __ip6_ins_rt net/ipv6/route.c:1304 [inline]
 ip6_route_add+0x89/0x130 net/ipv6/route.c:3772
 addrconf_prefix_route net/ipv6/addrconf.c:2463 [inline]
 fixup_permanent_addr net/ipv6/addrconf.c:3519 [inline]
 addrconf_permanent_addr+0x647/0x960 net/ipv6/addrconf.c:3543
 addrconf_notify+0x752/0xe90 net/ipv6/addrconf.c:3611
 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]
 __dev_notify_flags+0x2c1/0x560 net/core/dev.c:8585
 dev_change_flags+0xe8/0x1a0 net/core/dev.c:8623
 do_setlink+0xc06/0x3e10 net/core/rtnetlink.c:2735
 __rtnl_newlink net/core/rtnetlink.c:3413 [inline]
 rtnl_newlink+0x1534/0x18f0 net/core/rtnetlink.c:3533
 rtnetlink_rcv_msg+0xa31/0xcc0 net/core/rtnetlink.c:5613
 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2503
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5631
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x89c/0xb50 net/netlink/af_netlink.c:1914
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 __sys_sendto+0x467/0x620 net/socket.c:2006
 __do_sys_sendto net/socket.c:2018 [inline]
 __se_sys_sendto net/socket.c:2014 [inline]
 __x64_sys_sendto+0xe5/0x100 net/socket.c:2014
 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 ffff8881173f2000
 which belongs to the cache skbuff_head_cache of size 248
The buggy address is located 112 bytes inside of
 248-byte region [ffff8881173f2000, ffff8881173f20f8)
The buggy address belongs to the page:
page:ffffea00045cfc80 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881173f2280 pfn:0x1173f2
flags: 0x4000000000000200(slab)
raw: 4000000000000200 ffffea00045cff88 ffffea00045dd488 ffff888107d93c80
raw: ffff8881173f2280 00000000000c0001 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 95, ts 4303199084, free_ts 0
 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_alloc_node include/linux/slab.h:426 [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+0x605/0xb50 net/netlink/af_netlink.c:1889
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2376
 ___sys_sendmsg+0x236/0x2e0 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+0x1f9/0x2c0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8881173f1f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881173f1f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881173f2000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff8881173f2080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
 ffff8881173f2100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
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