================================================================== BUG: KCSAN: data-race in __add_to_page_cache_locked / ext4_writepages write to 0xffff88811eea9880 of 8 bytes by task 14045 on cpu 1: __add_to_page_cache_locked+0x2cc/0x6e0 mm/filemap.c:867 add_to_page_cache_lru+0xa0/0x1b0 mm/filemap.c:918 page_cache_readahead_unbounded+0x234/0x440 mm/readahead.c:228 ondemand_readahead+0x4e4/0x6e0 mm/readahead.c:273 page_cache_sync_readahead+0x178/0x1a0 mm/readahead.c:585 generic_file_buffered_read+0x2ae/0x1800 mm/filemap.c:2033 generic_file_read_iter+0x7d/0x3e0 mm/filemap.c:2307 ext4_file_read_iter+0x2d6/0x420 fs/ext4/file.c:74 call_read_iter include/linux/fs.h:1901 [inline] generic_file_splice_read+0x22a/0x310 fs/splice.c:312 do_splice_to fs/splice.c:870 [inline] splice_direct_to_actor+0x2a8/0x660 fs/splice.c:950 do_splice_direct+0xf2/0x170 fs/splice.c:1059 do_sendfile+0x562/0xb10 fs/read_write.c:1521 __do_sys_sendfile64 fs/read_write.c:1582 [inline] __se_sys_sendfile64 fs/read_write.c:1568 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1568 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88811eea9880 of 8 bytes by task 14052 on cpu 0: ext4_writepages+0x145/0x1ef0 fs/ext4/inode.c:2650 do_writepages+0x7b/0x150 mm/page-writeback.c:2354 __filemap_fdatawrite_range+0x19b/0x1d0 mm/filemap.c:421 file_write_and_wait_range+0x9f/0x120 mm/filemap.c:760 ext4_sync_file+0xfc/0x6e0 fs/ext4/fsync.c:151 vfs_fsync_range+0x107/0x120 fs/sync.c:200 generic_write_sync include/linux/fs.h:2882 [inline] ext4_buffered_write_iter+0x369/0x3b0 fs/ext4/file.c:277 ext4_file_write_iter+0x76f/0x1010 include/linux/fs.h:804 call_write_iter include/linux/fs.h:1907 [inline] do_iter_readv_writev+0x321/0x3c0 fs/read_write.c:694 do_iter_write+0x10e/0x470 fs/read_write.c:999 vfs_iter_write+0x4c/0x70 fs/read_write.c:1040 iter_file_splice_write+0x41a/0x770 fs/splice.c:750 do_splice_from fs/splice.c:846 [inline] direct_splice_actor+0x95/0x160 fs/splice.c:1016 splice_direct_to_actor+0x365/0x660 fs/splice.c:971 do_splice_direct+0xf2/0x170 fs/splice.c:1059 do_sendfile+0x562/0xb10 fs/read_write.c:1521 __do_sys_sendfile64 fs/read_write.c:1576 [inline] __se_sys_sendfile64 fs/read_write.c:1568 [inline] __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1568 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 14052 Comm: syz-executor.0 Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================