syzbot

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BUG: KCSAN: data-race in dentry_lru_isolate / lookup_fast

write to 0xffff88814d914a80 of 4 bytes by task 11530 on cpu 0:
 d_lru_shrink_move fs/dcache.c:480 [inline]
 dentry_lru_isolate+0x134/0x200 fs/dcache.c:1257
 __list_lru_walk_one+0x17b/0x370 mm/list_lru.c:231
 list_lru_walk_one+0x7c/0xa0 mm/list_lru.c:276
 list_lru_shrink_walk include/linux/list_lru.h:194 [inline]
 prune_dcache_sb+0x67/0xa0 fs/dcache.c:1280
 super_cache_scan+0x24e/0x300 fs/super.c:104
 do_shrink_slab+0x2ad/0x600 mm/vmscan.c:831
 shrink_slab_memcg+0x1b9/0x440 mm/vmscan.c:900
 shrink_slab+0x5c/0x1c0 mm/vmscan.c:979
 shrink_node_memcgs+0x28a/0x470 mm/vmscan.c:3182
 shrink_node+0x955/0x1200 mm/vmscan.c:3304
 shrink_zones+0x2c1/0x5d0 mm/vmscan.c:3542
 do_try_to_free_pages+0x195/0x760 mm/vmscan.c:3601
 try_to_free_mem_cgroup_pages+0x1d1/0x420 mm/vmscan.c:3916
 reclaim_high+0xcd/0x110 mm/memcontrol.c:2335
 mem_cgroup_handle_over_high+0x75/0x120 mm/memcontrol.c:2520
 resume_user_mode_work include/linux/resume_user_mode.h:58 [inline]
 exit_to_user_mode_loop+0xa5/0x130 kernel/entry/common.c:169
 exit_to_user_mode_prepare+0x69/0x90 kernel/entry/common.c:201
 irqentry_exit_to_user_mode+0x5/0x10 kernel/entry/common.c:307
 irqentry_exit+0xe/0x40 kernel/entry/common.c:408
 asm_exc_page_fault+0x22/0x30

read to 0xffff88814d914a80 of 4 bytes by task 11531 on cpu 1:
 d_revalidate fs/namei.c:855 [inline]
 lookup_fast+0xca/0x270 fs/namei.c:1634
 open_last_lookups fs/namei.c:3450 [inline]
 path_openat+0x457/0x1b00 fs/namei.c:3688
 do_filp_open+0x105/0x220 fs/namei.c:3718
 do_sys_openat2+0xb5/0x2a0 fs/open.c:1313
 do_sys_open fs/open.c:1329 [inline]
 __do_sys_openat fs/open.c:1345 [inline]
 __se_sys_openat fs/open.c:1340 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1340
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0068000c -> 0x0000800c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11531 Comm: syz-executor.4 Not tainted 6.0.0-rc6-syzkaller-00009-g60891ec99e14-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
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