================================================================== BUG: KCSAN: data-race in mm_update_next_owner / page_cache_ra_unbounded write to 0xffff8881385da02c of 4 bytes by task 14910 on cpu 1: memalloc_nofs_restore include/linux/sched/mm.h:259 [inline] page_cache_ra_unbounded+0x3e3/0x410 mm/readahead.c:239 do_page_cache_ra mm/readahead.c:267 [inline] force_page_cache_ra+0x246/0x280 mm/readahead.c:299 page_cache_sync_ra+0xcc/0xe0 mm/readahead.c:573 page_cache_sync_readahead include/linux/pagemap.h:864 [inline] filemap_get_pages mm/filemap.c:2442 [inline] filemap_read+0x388/0x1230 mm/filemap.c:2525 generic_file_read_iter+0x84/0x3e0 mm/filemap.c:2676 blkdev_read_iter+0xb3/0xc0 fs/block_dev.c:1720 call_read_iter include/linux/fs.h:2110 [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+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff8881385da02c of 4 bytes by task 20819 on cpu 0: mm_update_next_owner+0x1d9/0x520 kernel/exit.c:389 exit_mm+0x358/0x450 kernel/exit.c:501 do_exit+0x3ff/0x1560 kernel/exit.c:813 do_group_exit+0x19b/0x1a0 kernel/exit.c:923 __do_sys_exit_group+0xb/0x10 kernel/exit.c:934 __se_sys_exit_group+0x5/0x10 kernel/exit.c:932 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:932 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 20819 Comm: syz-executor.3 Not tainted 5.12.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================