================================================================== BUG: KCSAN: data-race in generic_file_buffered_read / generic_write_end write to 0xffff88810e7b3670 of 8 bytes by task 16960 on cpu 1: i_size_write include/linux/fs.h:871 [inline] generic_write_end+0x98/0x250 fs/buffer.c:2186 ext4_da_write_end+0x59b/0x760 fs/ext4/inode.c:3100 generic_perform_write+0x23e/0x3a0 mm/filemap.c:3322 ext4_buffered_write_iter+0x2e5/0x3d0 fs/ext4/file.c:270 ext4_file_write_iter+0x45e/0x1090 fs/ext4/file.c:503 call_write_iter include/linux/fs.h:1887 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4b0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x42a/0x780 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:933 splice_direct_to_actor+0x345/0x650 fs/splice.c:888 do_splice_direct+0xf5/0x170 fs/splice.c:976 do_sendfile+0x574/0xb70 fs/read_write.c:1257 __do_sys_sendfile64 fs/read_write.c:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88810e7b3670 of 8 bytes by task 16955 on cpu 0: i_size_read include/linux/fs.h:849 [inline] generic_file_buffered_read+0x13df/0x2110 mm/filemap.c:2294 generic_file_read_iter+0x80/0x3d0 mm/filemap.c:2535 ext4_file_read_iter+0x2d0/0x420 fs/ext4/file.c:74 call_read_iter include/linux/fs.h:1881 [inline] generic_file_splice_read+0x22a/0x310 fs/splice.c:311 do_splice_to fs/splice.c:788 [inline] splice_direct_to_actor+0x2aa/0x650 fs/splice.c:867 do_splice_direct+0xf5/0x170 fs/splice.c:976 do_sendfile+0x574/0xb70 fs/read_write.c:1257 __do_sys_sendfile64 fs/read_write.c:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 16955 Comm: syz-executor.4 Not tainted 5.9.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================