================================================================== BUG: KCSAN: data-race in __mpage_writepage / generic_write_end write to 0xffff88811e927a50 of 8 bytes by task 2862 on cpu 0: i_size_write include/linux/fs.h:876 [inline] generic_write_end+0x99/0x220 fs/buffer.c:2186 fat_write_end+0x4a/0x160 fs/fat/inode.c:249 generic_perform_write+0x23b/0x390 mm/filemap.c:3408 __generic_file_write_iter+0x154/0x330 mm/filemap.c:3526 generic_file_write_iter+0x2f3/0x3e0 mm/filemap.c:3558 call_write_iter include/linux/fs.h:1882 [inline] do_iter_readv_writev+0x32e/0x3d0 fs/read_write.c:713 do_iter_write+0x112/0x4b0 fs/read_write.c:1018 vfs_iter_write+0x4c/0x70 fs/read_write.c:1059 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+0x56a/0xba0 fs/read_write.c:1540 __do_sys_sendfile64 fs/read_write.c:1601 [inline] __se_sys_sendfile64 fs/read_write.c:1587 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1587 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88811e927a50 of 8 bytes by task 2854 on cpu 1: i_size_read include/linux/fs.h:854 [inline] __mpage_writepage+0x95/0x1070 fs/mpage.c:501 write_cache_pages+0x4cb/0x840 mm/page-writeback.c:2246 mpage_writepages+0x6d/0x120 fs/mpage.c:714 fat_writepages+0x20/0x30 fs/fat/inode.c:205 do_writepages+0x7b/0x150 mm/page-writeback.c:2352 __filemap_fdatawrite_range+0x19b/0x1d0 mm/filemap.c:422 filemap_write_and_wait_range+0x8b/0x2a0 mm/filemap.c:655 generic_file_read_iter+0x11d/0x3e0 mm/filemap.c:2375 call_read_iter include/linux/fs.h:1876 [inline] generic_file_splice_read+0x22b/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+0x56a/0xba0 fs/read_write.c:1540 __do_sys_sendfile64 fs/read_write.c:1595 [inline] __se_sys_sendfile64 fs/read_write.c:1587 [inline] __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1587 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: 1 PID: 2854 Comm: syz-executor.5 Not tainted 5.8.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================