================================================================== BUG: KCSAN: data-race in mm_update_next_owner / page_cache_ra_unbounded write to 0xffff88810552b0ac of 4 bytes by task 27759 on cpu 0: memalloc_nofs_save include/linux/sched/mm.h:245 [inline] page_cache_ra_unbounded+0xae/0x400 mm/readahead.c:193 do_page_cache_ra mm/readahead.c:267 [inline] force_page_cache_ra+0x236/0x270 mm/readahead.c:298 page_cache_sync_ra+0xb5/0xd0 mm/readahead.c:572 page_cache_sync_readahead include/linux/pagemap.h:840 [inline] filemap_get_pages mm/filemap.c:2375 [inline] filemap_read+0x380/0x1210 mm/filemap.c:2458 generic_file_read_iter+0x84/0x3e0 mm/filemap.c:2609 blkdev_read_iter+0xb3/0xc0 fs/block_dev.c:1727 call_read_iter include/linux/fs.h:1971 [inline] new_sync_read fs/read_write.c:415 [inline] vfs_read+0x565/0x5d0 fs/read_write.c:496 ksys_read+0xce/0x180 fs/read_write.c:634 __do_sys_read fs/read_write.c:644 [inline] __se_sys_read fs/read_write.c:642 [inline] __x64_sys_read+0x3e/0x50 fs/read_write.c:642 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88810552b0ac of 4 bytes by task 27844 on cpu 1: mm_update_next_owner+0x1d9/0x520 kernel/exit.c:388 exit_mm+0x358/0x450 kernel/exit.c:500 do_exit+0x3ff/0x1560 kernel/exit.c:812 do_group_exit+0x19b/0x1a0 kernel/exit.c:922 __do_sys_exit_group+0xb/0x10 kernel/exit.c:933 __se_sys_exit_group+0x5/0x10 kernel/exit.c:931 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:931 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 27844 Comm: syz-executor.0 Not tainted 5.12.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================