================================================================== BUG: KCSAN: data-race in __add_to_page_cache_locked / ext4_writepages read-write to 0xffff8880095e9838 of 8 bytes by task 22422 on cpu 1: __add_to_page_cache_locked+0x39d/0x7b0 mm/filemap.c:888 add_to_page_cache_lru+0xa0/0x1b0 mm/filemap.c:939 generic_file_buffered_read+0xf06/0x2110 mm/filemap.c:2437 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 read to 0xffff8880095e9838 of 8 bytes by task 22423 on cpu 0: ext4_writepages+0x134/0x1e10 fs/ext4/inode.c:2658 do_writepages+0x7b/0x150 mm/page-writeback.c:2352 __filemap_fdatawrite_range+0x19d/0x1d0 mm/filemap.c:422 filemap_write_and_wait_range+0x8b/0x2a0 mm/filemap.c:655 __iomap_dio_rw+0x38c/0x9b0 fs/iomap/direct-io.c:489 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:605 ext4_dio_read_iter fs/ext4/file.c:77 [inline] ext4_file_read_iter+0x3bd/0x420 fs/ext4/file.c:129 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: 22423 Comm: syz-executor.5 Not tainted 5.10.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================