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BUG: KCSAN: data-race in generic_fillattr / inode_add_bytes

read-write to 0xffff8881036d4108 of 8 bytes by task 4076 on cpu 0:
 __inode_add_bytes fs/stat.c:907 [inline]
 inode_add_bytes+0x47/0xe0 fs/stat.c:920
 __dquot_alloc_space+0x17d/0x890 fs/quota/dquot.c:1652
 dquot_alloc_space_nodirty include/linux/quotaops.h:292 [inline]
 dquot_alloc_block_nodirty include/linux/quotaops.h:319 [inline]
 shmem_inode_acct_blocks+0x125/0x230 mm/shmem.c:237
 shmem_alloc_and_add_folio mm/shmem.c:2005 [inline]
 shmem_get_folio_gfp+0x5d3/0xd90 mm/shmem.c:2528
 shmem_get_folio mm/shmem.c:2634 [inline]
 shmem_write_begin+0xfc/0x1f0 mm/shmem.c:3265
 generic_perform_write+0x186/0x490 mm/filemap.c:4374
 shmem_file_write_iter+0xc5/0xf0 mm/shmem.c:3440
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x57f/0x9a0 fs/read_write.c:687
 ksys_write+0xdc/0x1a0 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:747
 x64_sys_call+0x154e/0x2550 arch/x86/include/generated/asm/syscalls_64.h:2
 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 0xffff8881036d4108 of 8 bytes by task 3539 on cpu 1:
 generic_fillattr+0x283/0x340 fs/stat.c:106
 shmem_getattr+0x18b/0x210 mm/shmem.c:1315
 vfs_getattr_nosec+0x146/0x1e0 fs/stat.c:213
 vfs_getattr+0x48/0x60 fs/stat.c:262
 vfs_statx_path+0x28/0x140 fs/stat.c:299
 vfs_statx+0xc4/0x170 fs/stat.c:356
 vfs_fstatat+0x118/0x170 fs/stat.c:373
 __do_sys_newfstatat fs/stat.c:538 [inline]
 __se_sys_newfstatat+0x55/0x3e0 fs/stat.c:532
 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:532
 x64_sys_call+0xee6/0x2550 arch/x86/include/generated/asm/syscalls_64.h:263
 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: 0x0000000000001378 -> 0x0000000000001390

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3539 Comm: udevd Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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