syzbot

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

read to 0xffff8881058ea3b0 of 8 bytes by task 11097 on cpu 1:
 filemap_read+0xe0e/0x1430 mm/filemap.c:2687
 generic_file_read_iter+0x72/0x320 mm/filemap.c:2806
 ext4_file_read_iter+0x1c8/0x280
 call_read_iter include/linux/fs.h:2181 [inline]
 generic_file_splice_read+0xde/0x2b0 fs/splice.c:309
 do_splice_to fs/splice.c:793 [inline]
 splice_direct_to_actor+0x26c/0x620 fs/splice.c:865
 do_splice_direct+0xfb/0x180 fs/splice.c:974
 do_sendfile+0x3bf/0x910 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

write to 0xffff8881058ea3b0 of 8 bytes by task 11102 on cpu 0:
 filemap_read+0x11cc/0x1430 mm/filemap.c:2715
 generic_file_read_iter+0x72/0x320 mm/filemap.c:2806
 ext4_file_read_iter+0x1c8/0x280
 call_read_iter include/linux/fs.h:2181 [inline]
 generic_file_splice_read+0xde/0x2b0 fs/splice.c:309
 do_splice_to fs/splice.c:793 [inline]
 splice_direct_to_actor+0x26c/0x620 fs/splice.c:865
 do_splice_direct+0xfb/0x180 fs/splice.c:974
 do_sendfile+0x3bf/0x910 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000781000 -> 0x0000000000814000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11102 Comm: syz-executor.4 Not tainted 6.0.0-syzkaller-05118-g833477fce7a1-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
==================================================================