==================================================================
BUG: KASAN: use-after-free in check_igot_inode fs/ext4/inode.c:4953 [inline]
BUG: KASAN: use-after-free in __ext4_iget+0x3ac/0x40d0 fs/ext4/inode.c:5001
Read of size 8 at addr ffff8881d08bff50 by task syz.2.673/3105

CPU: 1 PID: 3105 Comm: syz.2.673 Tainted: G        W         5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 __dump_stack+0x1e/0x20 lib/dump_stack.c:77
 dump_stack+0x15b/0x1b8 lib/dump_stack.c:118
 print_address_description+0x8d/0x4c0 mm/kasan/report.c:384
 __kasan_report+0xef/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 check_igot_inode fs/ext4/inode.c:4953 [inline]
 __ext4_iget+0x3ac/0x40d0 fs/ext4/inode.c:5001
 ext4_quota_enable fs/ext4/super.c:6056 [inline]
 ext4_enable_quotas+0x33b/0x6c0 fs/ext4/super.c:6092
 ext4_fill_super+0x7f7c/0x8670 fs/ext4/super.c:4708
 mount_bdev+0x279/0x390 fs/super.c:1428
 ext4_mount+0x34/0x40 fs/ext4/super.c:6279
 legacy_get_tree+0xea/0x190 fs/fs_context.c:648
 vfs_get_tree+0x89/0x260 fs/super.c:1558
 do_new_mount+0x234/0x480 fs/namespace.c:2850
 do_mount+0x63a/0xd40 fs/namespace.c:3170
 ksys_mount+0xc5/0x100 fs/namespace.c:3379
 __do_sys_mount fs/namespace.c:3393 [inline]
 __se_sys_mount fs/namespace.c:3390 [inline]
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3390
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7fd40d1ec10a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 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:00007fd40b852e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd40b852ef0 RCX: 00007fd40d1ec10a
RDX: 0000200000000080 RSI: 0000200000000240 RDI: 00007fd40b852eb0
RBP: 0000200000000080 R08: 00007fd40b852ef0 R09: 0000000000004000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000200000000240
R13: 00007fd40b852eb0 R14: 0000000000000bb8 R15: 0000200000000140

Allocated by task 2890:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 __kasan_kmalloc+0x162/0x200 mm/kasan/common.c:529
 kasan_slab_alloc+0x12/0x20 mm/kasan/common.c:537
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slub.c:2829 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0xe2/0x270 mm/slub.c:2842
 __d_alloc+0x2d/0x6a0 fs/dcache.c:1695
 d_alloc+0x4b/0x1d0 fs/dcache.c:1774
 __lookup_hash+0xcb/0x250 fs/namei.c:1619
 filename_create+0x1d4/0x680 fs/namei.c:3785
 user_path_create fs/namei.c:3842 [inline]
 do_symlinkat+0x8f/0x3b0 fs/namei.c:4296
 __do_sys_symlinkat fs/namei.c:4317 [inline]
 __se_sys_symlinkat fs/namei.c:4314 [inline]
 __x64_sys_symlinkat+0x7b/0x90 fs/namei.c:4314
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Freed by task 17:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 kasan_set_free_info mm/kasan/common.c:345 [inline]
 __kasan_slab_free+0x1c3/0x280 mm/kasan/common.c:487
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:496
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook+0xb7/0x180 mm/slub.c:1494
 slab_free mm/slub.c:3080 [inline]
 kmem_cache_free+0x10c/0x2c0 mm/slub.c:3096
 __d_free+0x23/0x30 fs/dcache.c:271
 __rcu_reclaim kernel/rcu/rcu.h:222 [inline]
 rcu_do_batch+0x446/0x980 kernel/rcu/tree.c:2167
 rcu_core+0x4bd/0xbd0 kernel/rcu/tree.c:2387
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2396
 __do_softirq+0x236/0x660 kernel/softirq.c:292

The buggy address belongs to the object at ffff8881d08bfee0
 which belongs to the cache dentry of size 208
The buggy address is located 112 bytes inside of
 208-byte region [ffff8881d08bfee0, ffff8881d08bffb0)
The buggy address belongs to the page:
page:ffffea0007422fc0 refcount:1 mapcount:0 mapping:ffff8881f5d01900 index:0x0
flags: 0x8000000000000200(slab)
raw: 8000000000000200 ffffea0007a76cc0 0000000400000002 ffff8881f5d01900
raw: 0000000000000000 00000000000f000f 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Reclaimable, gfp_mask 0x112cd0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_RECLAIMABLE)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x35e/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894
 alloc_slab_page+0x3c/0x3b0 mm/slub.c:343
 allocate_slab mm/slub.c:1683 [inline]
 new_slab+0x93/0x420 mm/slub.c:1749
 new_slab_objects mm/slub.c:2505 [inline]
 ___slab_alloc+0x29e/0x420 mm/slub.c:2667
 __slab_alloc+0x63/0xa0 mm/slub.c:2707
 slab_alloc_node mm/slub.c:2792 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0x12c/0x270 mm/slub.c:2842
 __d_alloc+0x2d/0x6a0 fs/dcache.c:1695
 d_alloc fs/dcache.c:1774 [inline]
 d_alloc_parallel+0xd6/0x1330 fs/dcache.c:2528
 __lookup_slow+0x140/0x410 fs/namei.c:1731
 lookup_slow+0x57/0x70 fs/namei.c:1765
 walk_component+0x237/0x400 fs/namei.c:1885
 lookup_last fs/namei.c:2348 [inline]
 path_lookupat+0x179/0x3f0 fs/namei.c:2393
 filename_lookup+0x1bf/0x5f0 fs/namei.c:2423
 user_path_at_empty+0x43/0x50 fs/namei.c:2703
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1176 [inline]
 __free_pages_ok+0x7e4/0x910 mm/page_alloc.c:1438
 free_the_page mm/page_alloc.c:4956 [inline]
 __free_pages+0x8c/0x110 mm/page_alloc.c:4962
 __free_slab+0x218/0x2d0 mm/slub.c:1774
 free_slab mm/slub.c:1789 [inline]
 discard_slab mm/slub.c:1795 [inline]
 unfreeze_partials+0x165/0x1a0 mm/slub.c:2288
 put_cpu_partial+0xc1/0x180 mm/slub.c:2324
 __slab_free+0x2be/0x380 mm/slub.c:2971
 do_slab_free mm/slub.c:3068 [inline]
 ___cache_free+0xbb/0xd0 mm/slub.c:3087
 qlink_free+0x23/0x30 mm/kasan/quarantine.c:148
 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:167
 quarantine_reduce+0x1a8/0x200 mm/kasan/quarantine.c:260
 __kasan_kmalloc+0x42/0x200 mm/kasan/common.c:507
 kasan_slab_alloc+0x12/0x20 mm/kasan/common.c:537
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slub.c:2829 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0xe2/0x270 mm/slub.c:2842
 kmem_cache_alloc_node include/linux/slab.h:427 [inline]
 __alloc_skb+0x9e/0x500 net/core/skbuff.c:198
 alloc_skb include/linux/skbuff.h:1080 [inline]
 nlmsg_new include/net/netlink.h:888 [inline]
 inet_netconf_notify_devconf+0x169/0x220 net/ipv4/devinet.c:2121
 __devinet_sysctl_unregister net/ipv4/devinet.c:2629 [inline]
 devinet_sysctl_unregister net/ipv4/devinet.c:2653 [inline]
 inetdev_destroy net/ipv4/devinet.c:326 [inline]
 inetdev_event+0x7c6/0x1030 net/ipv4/devinet.c:1613

Memory state around the buggy address:
 ffff8881d08bfe00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881d08bfe80: fb fb fb fb fc fc fc fc fc fc fc fc fb fb fb fb
>ffff8881d08bff00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff8881d08bff80: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
 ffff8881d08c0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
EXT4-fs warning (device loop2): ext4_enable_quotas:6100: Failed to enable quota tracking (type=0, err=-13, ino=3). Please run e2fsck to fix.
EXT4-fs (loop2): mount failed