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BUG: KCSAN: data-race in has_bh_in_lru / invalidate_bh_lru

write to 0xffff888237c277e0 of 8 bytes by task 3638 on cpu 0:
 __invalidate_bh_lrus fs/buffer.c:1414 [inline]
 invalidate_bh_lru+0x8a/0xf0 fs/buffer.c:1426
 csd_do_func kernel/smp.c:143 [inline]
 smp_call_function_many_cond+0x72e/0xbc0 kernel/smp.c:983
 on_each_cpu_cond_mask+0x35/0x50 kernel/smp.c:1169
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1445
 invalidate_bdev+0x42/0x70 block/bdev.c:99
 __ext4_fill_super fs/ext4/super.c:5830 [inline]
 ext4_fill_super+0x2ccb/0x37b0 fs/ext4/super.c:5855
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1872
 get_tree_bdev+0x1f/0x30 fs/super.c:1895
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5887
 vfs_get_tree+0x57/0x1d0 fs/super.c:1932
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3772 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3848
 path_mount+0x4ad/0xb90 fs/namespace.c:4168
 do_mount fs/namespace.c:4181 [inline]
 __do_sys_mount fs/namespace.c:4397 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4374
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4374
 x64_sys_call+0xc3b/0x2550 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c277e0 of 8 bytes by task 3639 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1436
 cpu_needs_drain mm/folio.c:768 [inline]
 __lru_add_drain_all+0x2c1/0x520 mm/folio.c:860
 lru_cache_disable+0x1f/0x30 mm/folio.c:960
 do_mbind mm/mempolicy.c:1534 [inline]
 kernel_mbind mm/mempolicy.c:1760 [inline]
 __do_sys_mbind mm/mempolicy.c:1834 [inline]
 __se_sys_mbind+0x6cd/0xdd0 mm/mempolicy.c:1830
 __x64_sys_mbind+0x78/0x90 mm/mempolicy.c:1830
 x64_sys_call+0x1d78/0x2550 arch/x86/include/generated/asm/syscalls_64.h:238
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff88810593bea0 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3639 Comm: syz-executor636 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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