================================================================== BUG: KCSAN: data-race in filemap_read / simple_write_end write to 0xffff888106ddd950 of 8 bytes by task 21748 on cpu 0: i_size_write include/linux/fs.h:871 [inline] simple_write_end+0x293/0x330 fs/libfs.c:591 generic_perform_write+0x22a/0x3c0 mm/filemap.c:3667 __generic_file_write_iter+0x161/0x300 mm/filemap.c:3783 generic_file_write_iter+0x75/0x130 mm/filemap.c:3815 call_write_iter include/linux/fs.h:2114 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4c0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x40a/0x750 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:936 splice_direct_to_actor+0x345/0x650 fs/splice.c:891 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:1319 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xa9/0x130 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 0xffff888106ddd950 of 8 bytes by task 21758 on cpu 1: i_size_read include/linux/fs.h:849 [inline] filemap_read+0xd58/0x1220 mm/filemap.c:2562 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:1319 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xa9/0x130 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: 0x0000000000004dd5 -> 0x0000000000004dde Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 21758 Comm: syz-executor.0 Not tainted 5.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================