This avoids crashes in libc when cmsg is null and refrencing msg
structure when it is null
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The recvmsg handling is more complicated because it requires check the
returned kernel control message and make some convertions. For
!__ASSUME_TIME64_SYSCALLS it converts the first 32-bit time SO_TIMESTAMP
or SO_TIMESTAMPNS and appends it to the control buffer if has extra
space or returns MSG_CTRUNC otherwise. The 32-bit time field is kept
as-is.
Calls with __TIMESIZE=32 will see the converted 64-bit time control
messages as spurious control message of unknown type. Calls with
__TIMESIZE=64 running on pre-time64 kernels will see the original
message as a spurious control ones of unknown typ while running on
kernel with native 64-bit time support will only see the time64 version
of the control message.
Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15
kernel).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
