[Bug 46826] New: wineboot shows uninitialized memory use

https://bugs.winehq.org/show_bug.cgi?id=46826

Bug ID: 46826
           Summary: wineboot shows uninitialized memory use
           Product: Wine
           Version: 4.3
          Hardware: x86
                OS: Linux
            Status: NEW
          Keywords: download, source, valgrind
          Severity: normal
          Priority: P2
         Component: rpc
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 63855
  --> https://bugs.winehq.org/attachment.cgi?id=63855
valgrind log

==2430== Thread 5:
==2430== Syscall param writev(vector[...]) points to uninitialised byte(s)
==2430==    at 0x435D813: writev (writev.c:26)
==2430==    by 0x7BC7994F: send_request (server.c:228)
==2430==    by 0x7BC7A650: server_call_unlocked (server.c:288)
==2430==    by 0x7BC7A6A5: wine_server_call (server.c:321)
==2430==    by 0x7BC45DC7: server_write_file (file.c:621)
==2430==    by 0x7BC48439: NtWriteFile (file.c:1233)
==2430==    by 0x7B440C36: WriteFile (file.c:571)
==2430==    by 0x4C03821: process_send_command (rpc.c:1133)
==2430==    by 0x4C04F57: process_send_control (rpc.c:1203)
==2430==    by 0x4C078CC: process_send_start_message (services.c:1047)
==2430==    by 0x4C09589: service_start (services.c:1064)
==2430==    by 0x4C092BC: service_start_process (services.c:887)
==2430==    by 0x4C09545: service_start (services.c:1061)
==2430==    by 0x4C050E0: svcctl_StartServiceW (rpc.c:1227)
==2430==    by 0x4C0F65B: svcctl_svcctl_StartServiceW (svcctl_s.c:2583)
==2430==    by 0x4D74962: process_request_packet (rpc_server.c:439)
==2430==    by 0x4D75965: RPCRT4_process_packet (rpc_server.c:517)
==2430==    by 0x4D759F6: RPCRT4_worker_thread (rpc_server.c:539)
==2430==    by 0x7BC89783: process_rtl_work_item (threadpool.c:349)
==2430==    by 0x7BC8ACE7: threadpool_worker_proc (threadpool.c:2126)
==2430==  Address 0x555f514 is on thread 1's stack
==2430==  Uninitialised value was created by a stack allocation
==2430==    at 0x4C037E9: process_send_command (rpc.c:1127)
==2430==

==2430== Syscall param write(buf) points to uninitialised byte(s)
==2430==    at 0x4255CC3: write (write.c:27)
==2430==    by 0x7BC7990B: send_request (server.c:213)
==2430==    by 0x7BC7A650: server_call_unlocked (server.c:288)
==2430==    by 0x7BC95C2C: virtual_locked_server_call (virtual.c:2083)
==2430==    by 0x7BC45A00: server_read_file (file.c:578)
==2430==    by 0x7BC47C7A: NtReadFile (file.c:852)
==2430==    by 0x7B440796: ReadFile (file.c:448)
==2430==    by 0x4C03937: process_send_command (rpc.c:1151)
==2430==    by 0x4C04F57: process_send_control (rpc.c:1203)
==2430==    by 0x4C078CC: process_send_start_message (services.c:1047)
==2430==    by 0x4C09589: service_start (services.c:1064)
==2430==    by 0x4C092BC: service_start_process (services.c:887)
==2430==    by 0x4C09545: service_start (services.c:1061)
==2430==    by 0x4C050E0: svcctl_StartServiceW (rpc.c:1227)
==2430==    by 0x4C0F65B: svcctl_svcctl_StartServiceW (svcctl_s.c:2583)
==2430==    by 0x4D74962: process_request_packet (rpc_server.c:439)
==2430==    by 0x4D75965: RPCRT4_process_packet (rpc_server.c:517)
==2430==    by 0x4D759F6: RPCRT4_worker_thread (rpc_server.c:539)
==2430==    by 0x7BC89783: process_rtl_work_item (threadpool.c:349)
==2430==    by 0x7BC8ACE7: threadpool_worker_proc (threadpool.c:2126)
==2430==  Address 0x555f614 is on thread 1's stack
==2430==  Uninitialised value was created by a stack allocation
==2430==    at 0x4C037E9: process_send_command (rpc.c:1127)
==2430==

After that, several invalid reads in glibc (in a different thread), I'll attach
the full log