This fixes a potential vulnerability where data is written to spkt.buf
and rpkt.buf without a check on the array index. To fix this, we
check the array index (pkt->cnt) before storing the byte or
incrementing the count. This also means we no longer have a potential
signed integer overflow on the increment of pkt->cnt.
Fortunately, pppdump is not used in the normal process of setting up a
PPP connection, is not installed setuid-root, and is not invoked
automatically in any scenario that I am aware of.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
printf("%s aborted packet:\n ", dir);
q = " ";
}
+ if (pkt->cnt >= sizeof(pkt->buf)) {
+ printf("%s over-long packet truncated:\n ", dir);
+ q = " ";
+ }
nb = pkt->cnt;
p = pkt->buf;
pkt->cnt = 0;
c ^= 0x20;
pkt->esc = 0;
}
- pkt->buf[pkt->cnt++] = c;
+ if (pkt->cnt < sizeof(pkt->buf))
+ pkt->buf[pkt->cnt++] = c;
break;
}
}