syzbot

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BUG: KCSAN: data-race in generic_fillattr / inode_add_bytes

read-write to 0xffff888143ade9b8 of 8 bytes by task 10731 on cpu 1:
 __inode_add_bytes fs/stat.c:891 [inline]
 inode_add_bytes+0x45/0xd0 fs/stat.c:904
 __dquot_alloc_space+0x181/0x8a0 fs/quota/dquot.c:1695
 dquot_alloc_space_nodirty include/linux/quotaops.h:299 [inline]
 dquot_alloc_block_nodirty include/linux/quotaops.h:326 [inline]
 shmem_inode_acct_blocks+0x124/0x230 mm/shmem.c:232
 shmem_alloc_and_add_folio mm/shmem.c:1814 [inline]
 shmem_get_folio_gfp+0x5e2/0xd80 mm/shmem.c:2188
 shmem_get_folio mm/shmem.c:2293 [inline]
 shmem_write_begin+0xa0/0x1c0 mm/shmem.c:2898
 generic_perform_write+0x1b4/0x580 mm/filemap.c:4019
 shmem_file_write_iter+0xc8/0xf0 mm/shmem.c:3074
 __kernel_write_iter+0x24f/0x4e0 fs/read_write.c:523
 dump_emit_page fs/coredump.c:893 [inline]
 dump_user_range+0x3a7/0x550 fs/coredump.c:954
 elf_core_dump+0x1aeb/0x1c30 fs/binfmt_elf.c:2116
 do_coredump+0xfa7/0x1810 fs/coredump.c:767
 get_signal+0xdc1/0x1080 kernel/signal.c:2902
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 irqentry_exit_to_user_mode+0x9a/0x130 kernel/entry/common.c:231
 irqentry_exit+0x12/0x50 kernel/entry/common.c:334
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

read to 0xffff888143ade9b8 of 8 bytes by task 7723 on cpu 0:
 generic_fillattr+0x22d/0x2f0 fs/stat.c:64
 shmem_getattr+0x17b/0x200 mm/shmem.c:1157
 vfs_getattr_nosec fs/stat.c:166 [inline]
 vfs_getattr+0x19b/0x1e0 fs/stat.c:207
 vfs_statx_path fs/stat.c:251 [inline]
 vfs_statx+0x134/0x2f0 fs/stat.c:315
 vfs_fstatat+0xec/0x110 fs/stat.c:341
 __do_sys_newfstatat fs/stat.c:505 [inline]
 __se_sys_newfstatat+0x58/0x260 fs/stat.c:499
 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:499
 x64_sys_call+0x141f/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:263
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000008468 -> 0x0000000000008470

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 7723 Comm: syz-executor Not tainted 6.11.0-rc5-syzkaller-00176-g20371ba12063 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
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