==================================================================
BUG: KCSAN: data-race in __mark_inode_dirty / __writeback_single_inode

read-write to 0xffff8881048bcf08 of 4 bytes by task 51 on cpu 1:
 __writeback_single_inode+0x1f4/0x850 fs/fs-writeback.c:1716
 writeback_sb_inodes+0x458/0xa10 fs/fs-writeback.c:1976
 __writeback_inodes_wb+0x9a/0x1a0 fs/fs-writeback.c:2047
 wb_writeback+0x276/0x650 fs/fs-writeback.c:2158
 wb_check_start_all fs/fs-writeback.c:2284 [inline]
 wb_do_writeback fs/fs-writeback.c:2310 [inline]
 wb_workfn+0x510/0x960 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4de/0xa20 kernel/workqueue.c:3319
 worker_thread+0x52c/0x710 kernel/workqueue.c:3400
 kthread+0x4b7/0x540 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff8881048bcf08 of 4 bytes by task 4639 on cpu 0:
 __mark_inode_dirty+0x198/0x7e0 fs/fs-writeback.c:2549
 mark_buffer_dirty+0x149/0x230 fs/buffer.c:1199
 __block_commit_write fs/buffer.c:2189 [inline]
 block_page_mkwrite+0x29b/0x3f0 fs/buffer.c:2621
 ext4_page_mkwrite+0x75c/0xba0 fs/ext4/inode.c:6225
 do_page_mkwrite mm/memory.c:3256 [inline]
 do_shared_fault mm/memory.c:5490 [inline]
 do_fault mm/memory.c:5552 [inline]
 do_pte_missing mm/memory.c:4059 [inline]
 handle_pte_fault mm/memory.c:5893 [inline]
 __handle_mm_fault mm/memory.c:6036 [inline]
 handle_mm_fault+0x130c/0x2b30 mm/memory.c:6205
 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
 handle_page_fault arch/x86/mm/fault.c:1480 [inline]
 exc_page_fault+0x3b9/0x650 arch/x86/mm/fault.c:1538
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

value changed: 0x0001002a -> 0x00000020

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 4639 Comm: syz.1.432 Not tainted 6.14.0-syzkaller-10514-g7f2ff7b62617 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================