KCSAN: data-race in list_lru_count_one / list_lru_isolate_move

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: ef798c30 x86, kcsan: Enable KCSAN for x86
git tree: https://github.com/google/ktsan.git kcsan
console output: https://syzkaller.appspot.com/x/log.txt?x=10169edee00000
kernel config: https://syzkaller.appspot.com/x/.config?x=8077a73bd604a9d4
dashboard link: https://syzkaller.appspot.com/bug?extid=15d5bb386ee78dbe13c9
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org
linu...@kvack.org el...@google.com]

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+15d5bb...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in list_lru_count_one / list_lru_isolate_move

read to 0xffff8880ae3a2bb0 of 8 bytes by task 4825 on cpu 1:
list_lru_count_one+0xbd/0x130 mm/list_lru.c:193
list_lru_shrink_count include/linux/list_lru.h:123 [inline]
super_cache_count+0x11a/0x1b0 fs/super.c:148
do_shrink_slab+0xb7/0x5a0 mm/vmscan.c:479
shrink_slab_memcg mm/vmscan.c:631 [inline]
shrink_slab+0x46e/0x540 mm/vmscan.c:710
shrink_node+0x1ad/0xb30 mm/vmscan.c:2811
shrink_zones mm/vmscan.c:3025 [inline]
do_try_to_free_pages+0x242/0x940 mm/vmscan.c:3083
try_to_free_mem_cgroup_pages+0x1fd/0x4c0 mm/vmscan.c:3383
reclaim_high.constprop.0+0xf7/0x140 mm/memcontrol.c:2349
mem_cgroup_handle_over_high+0x96/0x180 mm/memcontrol.c:2430
tracehook_notify_resume include/linux/tracehook.h:197 [inline]
exit_to_usermode_loop+0x20c/0x2c0 arch/x86/entry/common.c:163
prepare_exit_to_usermode+0x180/0x1a0 arch/x86/entry/common.c:194
swapgs_restore_regs_and_return_to_usermode+0x0/0x40

write to 0xffff8880ae3a2bb0 of 8 bytes by task 13576 on cpu 0:
list_lru_isolate_move+0x127/0x160 mm/list_lru.c:180
inode_lru_isolate+0x1bc/0x380 fs/inode.c:777
__list_lru_walk_one+0x110/0x390 mm/list_lru.c:232
list_lru_walk_one+0x84/0xb0 mm/list_lru.c:276
list_lru_shrink_walk include/linux/list_lru.h:195 [inline]
prune_icache_sb+0x8a/0xc0 fs/inode.c:795
super_cache_scan+0x20b/0x2c0 fs/super.c:107
do_shrink_slab+0x2b6/0x5a0 mm/vmscan.c:561
shrink_slab_memcg mm/vmscan.c:631 [inline]
shrink_slab+0x46e/0x540 mm/vmscan.c:710
shrink_node+0x1ad/0xb30 mm/vmscan.c:2811
shrink_zones mm/vmscan.c:3025 [inline]
do_try_to_free_pages+0x242/0x940 mm/vmscan.c:3083
try_to_free_mem_cgroup_pages+0x1fd/0x4c0 mm/vmscan.c:3383
reclaim_high.constprop.0+0xf7/0x140 mm/memcontrol.c:2349
mem_cgroup_handle_over_high+0x96/0x180 mm/memcontrol.c:2430
tracehook_notify_resume include/linux/tracehook.h:197 [inline]
exit_to_usermode_loop+0x20c/0x2c0 arch/x86/entry/common.c:163
prepare_exit_to_usermode+0x180/0x1a0 arch/x86/entry/common.c:194
swapgs_restore_regs_and_return_to_usermode+0x0/0x40

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13576 Comm: syz-executor.0 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.