================================================================== BUG: KCSAN: data-race in shmem_add_to_page_cache / shmem_getpage_gfp write to 0xffff88810a759bb8 of 8 bytes by task 10687 on cpu 1: shmem_add_to_page_cache+0x5a0/0x6b0 mm/shmem.c:718 shmem_getpage_gfp+0x829/0x1930 mm/shmem.c:1927 shmem_fault+0x16c/0x450 mm/shmem.c:2114 __do_fault mm/memory.c:3625 [inline] do_read_fault+0x3fb/0x720 mm/memory.c:4019 do_fault mm/memory.c:4147 [inline] handle_pte_fault mm/memory.c:4387 [inline] __handle_mm_fault mm/memory.c:4522 [inline] handle_mm_fault+0x100c/0x1810 mm/memory.c:4620 faultin_page mm/gup.c:851 [inline] __get_user_pages+0xa42/0x1000 mm/gup.c:1070 populate_vma_page_range mm/gup.c:1403 [inline] __mm_populate+0x24d/0x380 mm/gup.c:1451 mm_populate include/linux/mm.h:2591 [inline] vm_mmap_pgoff+0x14c/0x1d0 mm/util.c:524 ksys_mmap_pgoff+0xe1/0x380 mm/mmap.c:1634 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88810a759bb8 of 8 bytes by task 10684 on cpu 0: shmem_recalc_inode mm/shmem.c:367 [inline] shmem_getpage_gfp+0xb5c/0x1930 mm/shmem.c:1937 shmem_fault+0x16c/0x450 mm/shmem.c:2114 __do_fault mm/memory.c:3625 [inline] do_read_fault+0x3fb/0x720 mm/memory.c:4019 do_fault mm/memory.c:4147 [inline] handle_pte_fault mm/memory.c:4387 [inline] __handle_mm_fault mm/memory.c:4522 [inline] handle_mm_fault+0x100c/0x1810 mm/memory.c:4620 do_user_addr_fault+0x43e/0x830 arch/x86/mm/fault.c:1393 handle_page_fault arch/x86/mm/fault.c:1450 [inline] exc_page_fault+0x94/0x2a0 arch/x86/mm/fault.c:1506 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:580 __get_user_nocheck_1+0x6/0x10 arch/x86/lib/getuser.S:103 fault_in_pages_readable include/linux/pagemap.h:747 [inline] iov_iter_fault_in_readable+0x155/0x3a0 lib/iov_iter.c:438 generic_perform_write+0xd2/0x3a0 mm/filemap.c:3402 ext4_buffered_write_iter+0x2e5/0x3e0 fs/ext4/file.c:270 ext4_file_write_iter+0x47a/0x1060 fs/ext4/file.c:503 call_write_iter include/linux/fs.h:1901 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x6f0/0x7e0 fs/read_write.c:605 ksys_write+0xce/0x180 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write fs/read_write.c:667 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:667 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: 0 PID: 10684 Comm: syz-executor.2 Not tainted 5.11.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================