syzbot

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BUG: KCSAN: data-race in __dput_to_list / step_into

read-write to 0xffff88810ad0a240 of 4 bytes by task 3129 on cpu 0:
 d_shrink_add fs/dcache.c:456 [inline]
 __dput_to_list+0x1eb/0x240 fs/dcache.c:928
 shrink_dentry_list+0x196/0x380 fs/dcache.c:1200
 prune_dcache_sb+0x81/0xb0 fs/dcache.c:1282
 super_cache_scan+0x26c/0x310 fs/super.c:104
 do_shrink_slab+0x2a0/0x640 mm/vmscan.c:853
 shrink_slab_memcg mm/vmscan.c:922 [inline]
 shrink_slab+0x2bc/0x520 mm/vmscan.c:1001
 shrink_node_memcgs mm/vmscan.c:6439 [inline]
 shrink_node+0xaf5/0x14f0 mm/vmscan.c:6473
 shrink_zones mm/vmscan.c:6711 [inline]
 do_try_to_free_pages+0x40d/0xc80 mm/vmscan.c:6773
 try_to_free_mem_cgroup_pages+0x1e2/0x480 mm/vmscan.c:7088
 reclaim_high+0xca/0x110 mm/memcontrol.c:2403
 mem_cgroup_handle_over_high+0x8c/0x1a0 mm/memcontrol.c:2588
 resume_user_mode_work include/linux/resume_user_mode.h:58 [inline]
 exit_to_user_mode_loop+0x99/0xe0 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0x6a/0xa0 kernel/entry/common.c:203
 irqentry_exit_to_user_mode+0x9/0x20 kernel/entry/common.c:309
 irqentry_exit+0x12/0x40 kernel/entry/common.c:412
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

read to 0xffff88810ad0a240 of 4 bytes by task 12790 on cpu 1:
 __follow_mount_rcu fs/namei.c:1481 [inline]
 handle_mounts fs/namei.c:1532 [inline]
 step_into+0xe7/0x800 fs/namei.c:1832
 walk_component+0x164/0x230 fs/namei.c:2000
 link_path_walk+0x4b8/0x7e0 fs/namei.c:2318
 path_openat+0x19b/0x1d00 fs/namei.c:3711
 do_filp_open+0xf6/0x200 fs/namei.c:3742
 do_sys_openat2+0xb5/0x2a0 fs/open.c:1348
 do_sys_open fs/open.c:1364 [inline]
 __do_sys_openat fs/open.c:1380 [inline]
 __se_sys_openat fs/open.c:1375 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1375
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0020000c -> 0x0000800c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12790 Comm: syz-executor.3 Not tainted 6.2.0-syzkaller-13163-g04a357b1f6f0-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023
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