[moderation] [exfat?] KCSAN: data-race in delete_from_page_cache_batch / filemap_write_and_wait_range (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 248951ddc14d Merge tag 'hwmon-for-v7.2-rc5' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10a9e2ea580000
kernel config: https://syzkaller.appspot.com/x/.config?x=84b3039e8461eef5
dashboard link: https://syzkaller.appspot.com/bug?extid=06c583556764913a92e7
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
CC: [hiro...@mail.parknet.co.jp linki...@kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org sj155...@samsung.com]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/bfdf74978a68/disk-248951dd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/41f897950fc4/vmlinux-248951dd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/675b5133b876/bzImage-248951dd.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+06c583...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in delete_from_page_cache_batch / filemap_write_and_wait_range

read-write to 0xffff88810610ce08 of 8 bytes by task 14787 on cpu 1:
page_cache_delete_batch mm/filemap.c:317 [inline]
delete_from_page_cache_batch+0x534/0x720 mm/filemap.c:336
truncate_inode_pages_range+0x1f3/0x7d0 mm/truncate.c:405
truncate_inode_pages mm/truncate.c:485 [inline]
truncate_pagecache+0x53/0x70 mm/truncate.c:798
fat_write_failed fs/fat/inode.c:218 [inline]
fat_write_end+0xa5/0x160 fs/fat/inode.c:247
generic_perform_write+0x314/0x490 mm/filemap.c:4379
__generic_file_write_iter+0x9e/0x120 mm/filemap.c:4475
generic_file_write_iter+0x77/0x1f0 mm/filemap.c:4501
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x57d/0x990 fs/read_write.c:687
ksys_pwrite64 fs/read_write.c:794 [inline]
__do_sys_pwrite64 fs/read_write.c:802 [inline]
__se_sys_pwrite64 fs/read_write.c:799 [inline]
__x64_sys_pwrite64+0xfd/0x150 fs/read_write.c:799
x64_sys_call+0xa2a/0x3020 arch/x86/include/generated/asm/syscalls_64.h:19
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810610ce08 of 8 bytes by task 14788 on cpu 0:
mapping_needs_writeback mm/filemap.c:634 [inline]
filemap_write_and_wait_range+0x59/0x370 mm/filemap.c:683
kiocb_write_and_wait mm/filemap.c:2904 [inline]
generic_file_read_iter+0xf4/0x320 mm/filemap.c:2978
copy_splice_read+0x47a/0x6b0 fs/splice.c:362
do_splice_read fs/splice.c:979 [inline]
splice_direct_to_actor+0x27c/0x680 fs/splice.c:1084
do_splice_direct_actor fs/splice.c:1202 [inline]
do_splice_direct+0x119/0x1a0 fs/splice.c:1228
do_sendfile+0x37d/0x640 fs/read_write.c:1371
__do_sys_sendfile64 fs/read_write.c:1432 [inline]
__se_sys_sendfile64 fs/read_write.c:1418 [inline]
__x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1418
x64_sys_call+0x2dc4/0x3020 arch/x86/include/generated/asm/syscalls_64.h:41
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000006 -> 0x0000000000000005

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 14788 Comm: syz.7.2910 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
==================================================================


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