================================================================== BUG: KCSAN: data-race in ondemand_readahead / read_pages read to 0xffff8881033094a4 of 4 bytes by task 4022 on cpu 0: ondemand_readahead+0x195/0x6c0 mm/readahead.c:594 page_cache_sync_ra+0x284/0x2a0 mm/readahead.c:709 page_cache_sync_readahead include/linux/pagemap.h:1211 [inline] filemap_get_pages+0x257/0xea0 mm/filemap.c:2601 filemap_read+0x223/0x680 mm/filemap.c:2696 generic_file_read_iter+0x76/0x320 mm/filemap.c:2843 ext4_file_read_iter+0x1cc/0x290 call_read_iter include/linux/fs.h:1862 [inline] generic_file_splice_read+0xe3/0x290 fs/splice.c:419 do_splice_to fs/splice.c:902 [inline] splice_direct_to_actor+0x25a/0x5f0 fs/splice.c:973 do_splice_direct+0x104/0x180 fs/splice.c:1082 do_sendfile+0x3b8/0x950 fs/read_write.c:1254 __do_sys_sendfile64 fs/read_write.c:1322 [inline] __se_sys_sendfile64 fs/read_write.c:1308 [inline] __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd write to 0xffff8881033094a4 of 4 bytes by task 4028 on cpu 1: read_pages+0x291/0x560 mm/readahead.c:173 page_cache_ra_unbounded+0x223/0x2e0 do_page_cache_ra mm/readahead.c:300 [inline] page_cache_ra_order+0xd5/0xf0 mm/readahead.c:560 do_sync_mmap_readahead+0x36a/0x3b0 mm/filemap.c:3193 filemap_fault+0x3d6/0xb70 mm/filemap.c:3285 __do_fault mm/memory.c:4176 [inline] do_read_fault mm/memory.c:4530 [inline] do_fault mm/memory.c:4659 [inline] do_pte_missing mm/memory.c:3647 [inline] handle_pte_fault mm/memory.c:4947 [inline] __handle_mm_fault mm/memory.c:5089 [inline] handle_mm_fault+0x12f4/0x2c60 mm/memory.c:5243 faultin_page mm/gup.c:925 [inline] __get_user_pages+0x363/0xc30 mm/gup.c:1147 populate_vma_page_range mm/gup.c:1543 [inline] __mm_populate+0x23d/0x370 mm/gup.c:1652 mm_populate include/linux/mm.h:3153 [inline] vm_mmap_pgoff+0x1a3/0x240 mm/util.c:548 ksys_mmap_pgoff+0x2ac/0x320 mm/mmap.c:1440 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00000003 -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 4028 Comm: syz-executor.4 Not tainted 6.4.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 ==================================================================