KCSAN: data-race in next_uptodate_page / simple_write_end

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 625acffd Merge tag 's390-5.13-5' of git://git.kernel.org/p..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10d676c8300000
kernel config: https://syzkaller.appspot.com/x/.config?x=a702dbad4961cdfa
dashboard link: https://syzkaller.appspot.com/bug?extid=736923f26ebfb8f2bd09
compiler: Debian clang version 11.0.1-2
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+736923...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in next_uptodate_page / simple_write_end

write to 0xffff88819c005d70 of 8 bytes by task 26666 on cpu 1:
i_size_write include/linux/fs.h:871 [inline]
simple_write_end+0x293/0x330 fs/libfs.c:592
generic_perform_write+0x23e/0x3a0 mm/filemap.c:3671
__generic_file_write_iter+0x161/0x300 mm/filemap.c:3789
generic_file_write_iter+0x75/0x130 mm/filemap.c:3821
call_write_iter include/linux/fs.h:2114 [inline]
new_sync_write fs/read_write.c:518 [inline]
vfs_write+0x69d/0x770 fs/read_write.c:605
ksys_write+0xce/0x180 fs/read_write.c:658
__do_sys_write fs/read_write.c:670 [inline]
__se_sys_write fs/read_write.c:667 [inline]
__x64_sys_write+0x3e/0x50 fs/read_write.c:667
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88819c005d70 of 8 bytes by task 26685 on cpu 0:
i_size_read include/linux/fs.h:849 [inline]
next_uptodate_page+0x323/0x670 mm/filemap.c:3146
next_map_page mm/filemap.c:3171 [inline]
filemap_map_pages+0x761/0x870 mm/filemap.c:3227
do_fault_around mm/memory.c:4006 [inline]
do_read_fault mm/memory.c:4020 [inline]
do_fault mm/memory.c:4153 [inline]
handle_pte_fault mm/memory.c:4412 [inline]
__handle_mm_fault mm/memory.c:4547 [inline]
handle_mm_fault+0xda3/0x1a70 mm/memory.c:4645
faultin_page mm/gup.c:908 [inline]
__get_user_pages+0x947/0xee0 mm/gup.c:1127
populate_vma_page_range mm/gup.c:1460 [inline]
__mm_populate+0x24d/0x380 mm/gup.c:1508
mm_populate include/linux/mm.h:2624 [inline]
vm_mmap_pgoff+0x142/0x1d0 mm/util.c:524
ksys_mmap_pgoff+0x2a8/0x380 mm/mmap.c:1638
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000d69000 -> 0x0000000000d6a000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 26685 Comm: syz-executor.0 Not tainted 5.13.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.