================================================================== BUG: KCSAN: data-race in ondemand_readahead / ondemand_readahead write to 0xffff88809c680d98 of 8 bytes by task 18861 on cpu 0: ondemand_readahead+0x39c/0x710 mm/readahead.c:470 page_cache_sync_readahead+0x1ad/0x1e0 mm/readahead.c:527 generic_file_buffered_read mm/filemap.c:2029 [inline] generic_file_read_iter+0xeb6/0x1440 mm/filemap.c:2302 ext4_file_read_iter fs/ext4/file.c:131 [inline] ext4_file_read_iter+0x10f/0x370 fs/ext4/file.c:114 call_read_iter include/linux/fs.h:1895 [inline] generic_file_splice_read+0x35c/0x500 fs/splice.c:313 do_splice_to+0xf2/0x130 fs/splice.c:892 splice_direct_to_actor+0x1b6/0x540 fs/splice.c:971 do_splice_direct+0x161/0x1e0 fs/splice.c:1080 do_sendfile+0x384/0x7f0 fs/read_write.c:1520 __do_sys_sendfile64 fs/read_write.c:1581 [inline] __se_sys_sendfile64 fs/read_write.c:1567 [inline] __x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1567 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88809c680d98 of 8 bytes by task 18865 on cpu 1: ondemand_readahead+0xfa/0x710 mm/readahead.c:409 page_cache_sync_readahead+0x1ad/0x1e0 mm/readahead.c:527 generic_file_buffered_read mm/filemap.c:2029 [inline] generic_file_read_iter+0xeb6/0x1440 mm/filemap.c:2302 ext4_file_read_iter fs/ext4/file.c:131 [inline] ext4_file_read_iter+0x10f/0x370 fs/ext4/file.c:114 call_read_iter include/linux/fs.h:1895 [inline] generic_file_splice_read+0x35c/0x500 fs/splice.c:313 do_splice_to+0xf2/0x130 fs/splice.c:892 splice_direct_to_actor+0x1b6/0x540 fs/splice.c:971 do_splice_direct+0x161/0x1e0 fs/splice.c:1080 do_sendfile+0x384/0x7f0 fs/read_write.c:1520 __do_sys_sendfile64 fs/read_write.c:1581 [inline] __se_sys_sendfile64 fs/read_write.c:1567 [inline] __x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1567 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 18865 Comm: syz-executor.5 Not tainted 5.6.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================