KCSAN: data-race in __filemap_add_folio / sync

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __filemap_add_folio / sync_bdevs (2) ext4				1	7d09h	7d09h	0/28	upstream: reported on 2024/09/21 08:17

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BUG: KCSAN: data-race in __filemap_add_folio / sync_bdevs

read-write to 0xffff88810241b708 of 8 bytes by task 2701 on cpu 1:
 __filemap_add_folio+0x379/0x6e0 mm/filemap.c:900
 filemap_add_folio+0x6b/0x150 mm/filemap.c:935
 __filemap_get_folio+0x50a/0x6d0 mm/filemap.c:1977
 pagecache_get_page+0x26/0xd0 mm/folio-compat.c:98
 find_or_create_page include/linux/pagemap.h:612 [inline]
 grow_dev_page+0x7a/0x5f0 fs/buffer.c:946
 grow_buffers fs/buffer.c:1011 [inline]
 __getblk_slow fs/buffer.c:1038 [inline]
 __getblk_gfp+0x112/0x1c0 fs/buffer.c:1333
 __getblk include/linux/buffer_head.h:411 [inline]
 jbd2_journal_get_descriptor_buffer+0xa6/0x1d0 fs/jbd2/journal.c:1019
 jbd2_journal_commit_transaction+0x9cf/0x30b0 fs/jbd2/commit.c:644
 kjournald2+0x233/0x420 fs/jbd2/journal.c:210
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffff88810241b708 of 8 bytes by task 5003 on cpu 0:
 sync_bdevs+0xdd/0x260 block/bdev.c:1033
 ksys_sync+0x7e/0xe0 fs/sync.c:105
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 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: 0x0000000000000395 -> 0x0000000000000396

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5003 Comm: syz-executor.4 Not tainted 6.2.0-rc5-syzkaller-00045-g948ef7bb70c4-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
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