KCSAN: data-race in filemap_read / filemap_read

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 251a1524293d Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=149a4c3a300000
kernel config: https://syzkaller.appspot.com/x/.config?x=325496b7f882bca
dashboard link: https://syzkaller.appspot.com/bug?extid=74bcf83a971e0c78aabd
compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]

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+74bcf8...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in filemap_read / filemap_read

write to 0xffff888102bb25b0 of 8 bytes by task 22117 on cpu 1:
filemap_read+0xf2c/0x1220 mm/filemap.c:2609
generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2701
call_read_iter include/linux/fs.h:2108 [inline]
generic_file_splice_read+0x22a/0x310 fs/splice.c:311
do_splice_to fs/splice.c:796 [inline]
splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
do_splice_direct+0xf5/0x170 fs/splice.c:979
do_sendfile+0x773/0xda0 fs/read_write.c:1260
__do_sys_sendfile64 fs/read_write.c:1325 [inline]
__se_sys_sendfile64 fs/read_write.c:1311 [inline]
__x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888102bb25b0 of 8 bytes by task 22120 on cpu 0:
filemap_read+0xdd4/0x1220 mm/filemap.c:2578
generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2701
call_read_iter include/linux/fs.h:2108 [inline]
generic_file_splice_read+0x22a/0x310 fs/splice.c:311
do_splice_to fs/splice.c:796 [inline]
splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
do_splice_direct+0xf5/0x170 fs/splice.c:979
do_sendfile+0x773/0xda0 fs/read_write.c:1260
__do_sys_sendfile64 fs/read_write.c:1325 [inline]
__se_sys_sendfile64 fs/read_write.c:1311 [inline]
__x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000000cbc00 -> 0x00000000000cce00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 22120 Comm: syz-executor.1 Tainted: G W 5.14.0-rc4-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.