ipmi: check return of qemu_chr_fe_write() for errors

The continue_send() method in ipmi_bmc_extern.c directly
assigns the return value of qemu_chr_fe_write() to the
variable tracking the I/O buffer offset. This ignores the
possibility that the return value could be -1 and so will
cause I/O go backwards on EAGAIN. Fortunately 'outpos' is
unsigned, so can't go negative - it will become MAX_INT
which will cause the loop to stop, and avoid an accidental
out of bounds array access.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1473170165-540-2-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Daniel P. Berrange 2016-09-06 14:56:02 +01:00 committed by Paolo Bonzini
parent e270d00afa
commit b72981b910
1 changed files with 6 additions and 2 deletions

View File

@ -100,12 +100,16 @@ ipmb_checksum(const unsigned char *data, int size, unsigned char start)
static void continue_send(IPMIBmcExtern *ibe)
{
int ret;
if (ibe->outlen == 0) {
goto check_reset;
}
send:
ibe->outpos += qemu_chr_fe_write(ibe->chr, ibe->outbuf + ibe->outpos,
ibe->outlen - ibe->outpos);
ret = qemu_chr_fe_write(ibe->chr, ibe->outbuf + ibe->outpos,
ibe->outlen - ibe->outpos);
if (ret > 0) {
ibe->outpos += ret;
}
if (ibe->outpos < ibe->outlen) {
/* Not fully transmitted, try again in a 10ms */
timer_mod_ns(ibe->extern_timer,