netlink: 'syz.0.221': attribute type 4 has an invalid length.
netlink: 'syz.0.221': attribute type 4 has an invalid length.
==================================================================
BUG: KASAN: use-after-free in trace_event_raw_event_mm_filemap_op_page_cache+0x38a/0x3b0 include/trace/events/filemap.h:-1
Read of size 4 at addr ffff88810fc2a010 by task syz.0.221/1304

CPU: 0 PID: 1304 Comm: syz.0.221 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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+0x100/0x140 mm/kasan/report.c:452
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 trace_event_raw_event_mm_filemap_op_page_cache+0x38a/0x3b0 include/trace/events/filemap.h:-1
 trace_mm_filemap_delete_from_page_cache include/trace/events/filemap.h:47 [inline]
 __delete_from_page_cache+0x429/0x470 mm/filemap.c:241
 __remove_mapping+0x581/0x6b0 mm/vmscan.c:985
 shrink_page_list+0x21ee/0x4160 mm/vmscan.c:1498
 shrink_inactive_list+0x90c/0xef0 mm/vmscan.c:2075
 shrink_list mm/vmscan.c:2294 [inline]
 shrink_lruvec+0x2806/0x2d70 mm/vmscan.c:5473
 shrink_node_memcgs mm/vmscan.c:5660 [inline]
 shrink_node+0xee0/0x2690 mm/vmscan.c:5690
 shrink_zones mm/vmscan.c:5896 [inline]
 do_try_to_free_pages+0x602/0x1590 mm/vmscan.c:5954
 try_to_free_mem_cgroup_pages+0x261/0x610 mm/vmscan.c:6272
 mem_cgroup_force_empty mm/memcontrol.c:3520 [inline]
 mem_cgroup_force_empty_write+0x130/0x170 mm/memcontrol.c:3541
 cgroup_file_write+0x294/0x560 kernel/cgroup/cgroup.c:3902
 kernfs_fop_write_iter+0x2bd/0x400 fs/kernfs/file.c:296
 call_write_iter include/linux/fs.h:2072 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x770/0xd70 fs/read_write.c:605
 ksys_write+0x14a/0x260 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:667
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7ff3ccbfa159
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:00007ff3cb653028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff3cce81fa0 RCX: 00007ff3ccbfa159
RDX: 0000000000000078 RSI: 0000200000000300 RDI: 0000000000000009
RBP: 00007ff3ccc91024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff3cce82038 R14: 00007ff3cce81fa0 R15: 00007ffc37e3bb38

Allocated by task 865:
 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+0xb7/0xe0 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+0x15a/0x2d0 mm/slub.c:2965
 getname_flags+0xba/0x510 fs/namei.c:141
 getname+0x19/0x20 fs/namei.c:212
 do_sys_openat2+0xde/0x750 fs/open.c:1213
 do_sys_open fs/open.c:1235 [inline]
 __do_sys_openat fs/open.c:1251 [inline]
 __se_sys_openat fs/open.c:1246 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1246
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 865:
 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
 putname+0xfe/0x150 fs/namei.c:262
 do_sys_openat2+0x68e/0x750 fs/open.c:1228
 do_sys_open fs/open.c:1235 [inline]
 __do_sys_openat fs/open.c:1251 [inline]
 __se_sys_openat fs/open.c:1246 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1246
 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 ffff88810fc29100
 which belongs to the cache names_cache of size 4096
The buggy address is located 3856 bytes inside of
 4096-byte region [ffff88810fc29100, ffff88810fc2a100)
The buggy address belongs to the page:
page:ffffea00043f0a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10fc28
head:ffffea00043f0a00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff88810018a780
raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 865, ts 46433780983, free_ts 46425064505
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x176/0x190 mm/page_alloc.c:2462
 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x29a/0x640 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+0x2f8/0x4c0 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+0x1a4/0x2d0 mm/slub.c:2965
 getname_flags+0xba/0x510 fs/namei.c:141
 user_path_at_empty+0x2f/0x50 fs/namei.c:2790
 user_path_at include/linux/namei.h:60 [inline]
 ksys_umount fs/namespace.c:1768 [inline]
 __do_sys_umount fs/namespace.c:1776 [inline]
 __se_sys_umount fs/namespace.c:1774 [inline]
 __x64_sys_umount+0xf9/0x170 fs/namespace.c:1774
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
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_pages_ok+0x80b/0x830 mm/page_alloc.c:1629
 free_the_page mm/page_alloc.c:5445 [inline]
 __free_pages+0xd8/0x390 mm/page_alloc.c:5454
 __free_slab+0xcf/0x190 mm/slub.c:1899
 free_slab mm/slub.c:1914 [inline]
 discard_slab mm/slub.c:1920 [inline]
 unfreeze_partials+0x150/0x180 mm/slub.c:2415
 put_cpu_partial+0xc1/0x180 mm/slub.c:2451
 __slab_free+0x2c9/0x3a0 mm/slub.c:3100
 do_slab_free mm/slub.c:3196 [inline]
 ___cache_free+0x10e/0x130 mm/slub.c:3215
 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157
 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:440
 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_trace+0x155/0x2e0 mm/slub.c:2977
 kmalloc include/linux/slab.h:555 [inline]
 kzalloc include/linux/slab.h:667 [inline]
 kobject_uevent_env+0x271/0x700 lib/kobject_uevent.c:539
 kobject_uevent+0x1d/0x30 lib/kobject_uevent.c:657
 __loop_clr_fd+0x61e/0x9f0 drivers/block/loop.c:1255

Memory state around the buggy address:
 ffff88810fc29f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88810fc29f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88810fc2a000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88810fc2a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88810fc2a100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================