================================================================== BUG: KCSAN: data-race in mm_update_next_owner / page_cache_readahead_unbounded write to 0xffff88811e17a0a4 of 4 bytes by task 13605 on cpu 0: memalloc_nofs_restore include/linux/sched/mm.h:273 [inline] page_cache_readahead_unbounded+0x409/0x440 mm/readahead.c:245 __do_page_cache_readahead mm/readahead.c:273 [inline] force_page_cache_readahead+0x1ec/0x220 mm/readahead.c:303 page_cache_sync_readahead+0x191/0x1a0 mm/readahead.c:580 generic_file_buffered_read+0x2c5/0x19e0 mm/filemap.c:2033 generic_file_read_iter+0x7d/0x3e0 mm/filemap.c:2326 blkdev_read_iter+0xb3/0xc0 fs/block_dev.c:2044 call_read_iter include/linux/fs.h:1902 [inline] new_sync_read fs/read_write.c:415 [inline] vfs_read+0x523/0x590 fs/read_write.c:481 ksys_read+0xce/0x180 fs/read_write.c:607 __do_sys_read fs/read_write.c:617 [inline] __se_sys_read fs/read_write.c:615 [inline] __x64_sys_read+0x3e/0x50 fs/read_write.c:615 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88811e17a0a4 of 4 bytes by task 20386 on cpu 1: mm_update_next_owner+0x1d9/0x4a0 kernel/exit.c:386 exit_mm+0x2c0/0x330 kernel/exit.c:481 do_exit+0x415/0x16e0 kernel/exit.c:792 do_group_exit+0x17a/0x180 kernel/exit.c:903 __do_sys_exit_group+0xb/0x10 kernel/exit.c:914 __se_sys_exit_group+0x5/0x10 kernel/exit.c:912 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:912 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 20386 Comm: syz-executor.1 Not tainted 5.8.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================