================================================================== BUG: KCSAN: data-race in filemap_map_pages / shmem_write_end write to 0xffff888000175a88 of 8 bytes by task 19021 on cpu 0: i_size_write include/linux/fs.h:888 [inline] shmem_write_end+0x83/0x4f0 mm/shmem.c:2493 generic_perform_write+0x1d3/0x320 mm/filemap.c:3316 __generic_file_write_iter+0x251/0x380 mm/filemap.c:3434 generic_file_write_iter+0x28c/0x390 mm/filemap.c:3466 call_write_iter include/linux/fs.h:1895 [inline] do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693 do_iter_write fs/read_write.c:970 [inline] do_iter_write+0x13b/0x3c0 fs/read_write.c:951 vfs_iter_write+0x5c/0x80 fs/read_write.c:983 iter_file_splice_write+0x4c0/0x7f0 fs/splice.c:746 do_splice_from fs/splice.c:848 [inline] direct_splice_actor+0xa0/0xc0 fs/splice.c:1020 splice_direct_to_actor+0x215/0x510 fs/splice.c:975 do_splice_direct+0x161/0x1e0 fs/splice.c:1063 do_sendfile+0x384/0x7f0 fs/read_write.c:1464 __do_sys_sendfile64 fs/read_write.c:1519 [inline] __se_sys_sendfile64 fs/read_write.c:1511 [inline] __x64_sys_sendfile64+0xbe/0x140 fs/read_write.c:1511 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff888000175a88 of 8 bytes by task 19029 on cpu 1: filemap_map_pages+0x812/0x990 mm/filemap.c:2664 do_fault_around mm/memory.c:3450 [inline] do_read_fault mm/memory.c:3484 [inline] do_fault mm/memory.c:3618 [inline] handle_pte_fault mm/memory.c:3849 [inline] __handle_mm_fault+0x2544/0x2c70 mm/memory.c:3973 handle_mm_fault+0x21b/0x530 mm/memory.c:4010 do_user_addr_fault arch/x86/mm/fault.c:1441 [inline] __do_page_fault+0x456/0x8d0 arch/x86/mm/fault.c:1506 do_page_fault+0x38/0x194 arch/x86/mm/fault.c:1530 page_fault+0x34/0x40 arch/x86/entry/entry_64.S:1202 copy_user_generic_unrolled+0x86/0xc0 arch/x86/lib/copy_user_64.S:89 copy_from_user include/linux/uaccess.h:144 [inline] __get_filter+0x100/0x1c0 net/core/filter.c:1476 sk_attach_filter+0x27/0xa0 net/core/filter.c:1507 sock_setsockopt+0x16d1/0x1850 net/core/sock.c:1001 __sys_setsockopt+0x34b/0x370 net/socket.c:2080 __do_sys_setsockopt net/socket.c:2100 [inline] __se_sys_setsockopt net/socket.c:2097 [inline] __x64_sys_setsockopt+0x70/0x90 net/socket.c:2097 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 19029 Comm: syz-executor.5 Not tainted 5.4.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================