@@ -290,10 +290,15 @@ static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *
facilities->source_ndigis = 0;
facilities->dest_ndigis = 0;
for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
- if (pt[6] & AX25_HBIT)
+ if (pt[6] & AX25_HBIT) {
+ if (facilities->dest_ndigis >= ROSE_MAX_DIGIS)
+ return -1;
memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
- else
+ } else {
+ if (facilities->source_ndigis >= ROSE_MAX_DIGIS)
+ return -1;
memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
+ }
}
}
p += l + 2;
@@ -333,6 +338,11 @@ static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *fac
case 0xC0:
l = p[1];
+
+ /* Prevent overflows*/
+ if (l < 10 || l > 20)
+ return -1;
+
if (*p == FAC_CCITT_DEST_NSAP) {
memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
memcpy(callsign, p + 12, l - 10);
@@ -373,12 +383,16 @@ int rose_parse_facilities(unsigned char *p,
switch (*p) {
case FAC_NATIONAL: /* National */
len = rose_parse_national(p + 1, facilities, facilities_len - 1);
+ if (len < 0)
+ return 0;
facilities_len -= len + 1;
p += len + 1;
break;
case FAC_CCITT: /* CCITT */
len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
+ if (len < 0)
+ return 0;
facilities_len -= len + 1;
p += len + 1;
break;
When parsing the FAC_NATIONAL_DIGIS facilities field, it's possible for a remote host to provide more digipeaters than expected, resulting in heap corruption. Check against ROSE_MAX_DIGIS to prevent overflows, and abort facilities parsing on failure. Additionally, when parsing the FAC_CCITT_DEST_NSAP and FAC_CCITT_SRC_NSAP facilities fields, a remote host can provide a length of less than 10, resulting in an underflow in a memcpy size, causing a kernel panic due to massive heap corruption. A length of greater than 20 results in a stack overflow of the callsign array. Abort facilities parsing on these invalid length values. Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> Cc: stable@kernel.org --- net/rose/rose_subr.c | 18 ++++++++++++++++-- 1 files changed, 16 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html