[PATCH net-next v4 13/17] net: pktgen: fix access outside of user given buffer in pktgen_if_write()

Honour the user given buffer size for the hex32_arg(), num_arg(), strn_len(), get_imix_entries() and get_labels() calls (otherwise they will access memory outside of the user given buffer).

Signed-off-by: Peter Seiderer ps.report@gmx.net --- Changes v3 -> v4: - replace C99 comment (suggested by Paolo Abeni) - drop available characters check in strn_len() (suggested by Paolo Abeni) - factored out patch 'net: pktgen: align some variable declarations to the most common pattern' (suggested by Paolo Abeni) - factored out patch 'net: pktgen: remove extra tmp variable (re-use len instead)' (suggested by Paolo Abeni) - factored out patch 'net: pktgen: remove some superfluous variable initializing' (suggested by Paolo Abeni) - factored out patch 'net: pktgen: fix mpls maximum labels list parsing' (suggested by Paolo Abeni) - factored out 'net: pktgen: hex32_arg/num_arg error out in case no characters are available' (suggested by Paolo Abeni) - factored out 'net: pktgen: num_arg error out in case no valid character is parsed' (suggested by Paolo Abeni)

Changes v2 -> v3: - no changes

Changes v1 -> v2: - additional fix get_imix_entries() and get_labels() --- net/core/pktgen.c | 176 ++++++++++++++++++++++++++++++---------------- 1 file changed, 117 insertions(+), 59 deletions(-)

diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 0fd15f21119b..3c42ecf17ba2 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -851,10 +851,11 @@ static int strn_len(const char __user * user_buffer, unsigned int maxlen) * "size1,weight_1 size2,weight_2 ... size_n,weight_n" for example. */ static int get_imix_entries(const char __user *buffer, + unsigned int maxlen, struct pktgen_dev *pkt_dev) { char c; - int i = 0, len; + int i = 0, max, len;

pkt_dev->n_imix_entries = 0;

@@ -865,10 +866,13 @@ static int get_imix_entries(const char __user *buffer, if (pkt_dev->n_imix_entries >= MAX_IMIX_ENTRIES) return -E2BIG;

- len = num_arg(&buffer[i], DEC_10_DIGITS, &size); + max = min(DEC_10_DIGITS, maxlen - i); + len = num_arg(&buffer[i], max, &size); if (len < 0) return len; i += len; + if (i >= maxlen) + return -EINVAL; if (get_user(c, &buffer[i])) return -EFAULT; /* Check for comma between size_i and weight_i */ @@ -879,7 +883,8 @@ static int get_imix_entries(const char __user *buffer, if (size < 14 + 20 + 8) size = 14 + 20 + 8;

- len = num_arg(&buffer[i], DEC_10_DIGITS, &weight); + max = min(DEC_10_DIGITS, maxlen - i); + len = num_arg(&buffer[i], max, &weight); if (len < 0) return len; if (weight <= 0) @@ -889,21 +894,23 @@ static int get_imix_entries(const char __user *buffer, pkt_dev->imix_entries[pkt_dev->n_imix_entries].weight = weight;

i += len; + pkt_dev->n_imix_entries++; + + if (i >= maxlen) + break; if (get_user(c, &buffer[i])) return -EFAULT; - i++; - pkt_dev->n_imix_entries++; } while (c == ' ');

return i; }

-static int get_labels(const char __user *buffer, struct pktgen_dev *pkt_dev) +static int get_labels(const char __user *buffer, int maxlen, struct pktgen_dev *pkt_dev) { char c; - int i = 0, len; unsigned int n = 0; + int i = 0, max, len;

pkt_dev->nr_labels = 0; do { @@ -912,17 +919,20 @@ static int get_labels(const char __user *buffer, struct pktgen_dev *pkt_dev) if (n >= MAX_MPLS_LABELS) return -E2BIG;

- len = hex32_arg(&buffer[i], HEX_8_DIGITS, &tmp); + max = min(HEX_8_DIGITS, maxlen - i); + len = hex32_arg(&buffer[i], max, &tmp); if (len <= 0) return len; pkt_dev->labels[n] = htonl(tmp); if (pkt_dev->labels[n] & MPLS_STACK_BOTTOM) pkt_dev->flags |= F_MPLS_RND; i += len; + n++; + if (i >= maxlen) + break; if (get_user(c, &buffer[i])) return -EFAULT; i++; - n++; } while (c == ',');

pkt_dev->nr_labels = n; @@ -986,8 +996,8 @@ static ssize_t pktgen_if_write(struct file *file, i = len;

/* Read variable name */ - - len = strn_len(&user_buffer[i], sizeof(name) - 1); + max = min(sizeof(name) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

@@ -1015,7 +1025,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "min_pkt_size")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1032,7 +1043,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "max_pkt_size")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1051,7 +1063,8 @@ static ssize_t pktgen_if_write(struct file *file, /* Shortcut for min = max */

if (!strcmp(name, "pkt_size")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1071,7 +1084,8 @@ static ssize_t pktgen_if_write(struct file *file, if (pkt_dev->clone_skb > 0) return -EINVAL;

- len = get_imix_entries(&user_buffer[i], pkt_dev); + max = count - i; + len = get_imix_entries(&user_buffer[i], max, pkt_dev); if (len < 0) return len;

@@ -1082,7 +1096,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "debug")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1093,7 +1108,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "frags")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1103,7 +1119,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "delay")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1118,7 +1135,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "rate")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1133,7 +1151,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "ratep")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1148,7 +1167,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "udp_src_min")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1161,7 +1181,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "udp_dst_min")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1174,7 +1195,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "udp_src_max")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1187,7 +1209,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "udp_dst_max")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1200,7 +1223,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "clone_skb")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len; /* clone_skb is not supported for netif_receive xmit_mode and @@ -1221,7 +1245,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "count")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1232,7 +1257,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "src_mac_count")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1246,7 +1272,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "dst_mac_count")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1260,7 +1287,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "burst")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1279,7 +1307,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "node")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1300,11 +1329,12 @@ static ssize_t pktgen_if_write(struct file *file, if (!strcmp(name, "xmit_mode")) { char f[32];

- memset(f, 0, 32); - len = strn_len(&user_buffer[i], sizeof(f) - 1); + max = min(sizeof(f) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

+ memset(f, 0, sizeof(f)); if (copy_from_user(f, &user_buffer[i], len)) return -EFAULT; i += len; @@ -1340,11 +1370,12 @@ static ssize_t pktgen_if_write(struct file *file, char f[32]; char *end;

- memset(f, 0, 32); - len = strn_len(&user_buffer[i], sizeof(f) - 1); + max = min(sizeof(f) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

+ memset(f, 0, 32); if (copy_from_user(f, &user_buffer[i], len)) return -EFAULT; i += len; @@ -1389,7 +1420,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "dst_min") || !strcmp(name, "dst")) { - len = strn_len(&user_buffer[i], sizeof(pkt_dev->dst_min) - 1); + max = min(sizeof(pkt_dev->dst_min) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

@@ -1409,7 +1441,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "dst_max")) { - len = strn_len(&user_buffer[i], sizeof(pkt_dev->dst_max) - 1); + max = min(sizeof(pkt_dev->dst_max) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

@@ -1429,7 +1462,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "dst6")) { - len = strn_len(&user_buffer[i], sizeof(buf) - 1); + max = min(sizeof(buf) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

@@ -1452,7 +1486,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "dst6_min")) { - len = strn_len(&user_buffer[i], sizeof(buf) - 1); + max = min(sizeof(buf) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

@@ -1474,7 +1509,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "dst6_max")) { - len = strn_len(&user_buffer[i], sizeof(buf) - 1); + max = min(sizeof(buf) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

@@ -1495,7 +1531,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "src6")) { - len = strn_len(&user_buffer[i], sizeof(buf) - 1); + max = min(sizeof(buf) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

@@ -1518,7 +1555,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "src_min")) { - len = strn_len(&user_buffer[i], sizeof(pkt_dev->src_min) - 1); + max = min(sizeof(pkt_dev->src_min) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

@@ -1538,7 +1576,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "src_max")) { - len = strn_len(&user_buffer[i], sizeof(pkt_dev->src_max) - 1); + max = min(sizeof(pkt_dev->src_max) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

@@ -1558,7 +1597,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "dst_mac")) { - len = strn_len(&user_buffer[i], sizeof(valstr) - 1); + max = min(sizeof(valstr) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

@@ -1575,7 +1615,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "src_mac")) { - len = strn_len(&user_buffer[i], sizeof(valstr) - 1); + max = min(sizeof(valstr) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;

@@ -1599,7 +1640,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "flows")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1613,7 +1655,8 @@ static ssize_t pktgen_if_write(struct file *file, } #ifdef CONFIG_XFRM if (!strcmp(name, "spi")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1624,7 +1667,8 @@ static ssize_t pktgen_if_write(struct file *file, } #endif if (!strcmp(name, "flowlen")) { - len = num_arg(&user_buffer[i], DEC_10_DIGITS, &value); + max = min(DEC_10_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1635,7 +1679,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "queue_map_min")) { - len = num_arg(&user_buffer[i], DEC_5_DIGITS, &value); + max = min(DEC_5_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1646,7 +1691,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "queue_map_max")) { - len = num_arg(&user_buffer[i], DEC_5_DIGITS, &value); + max = min(DEC_5_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1659,7 +1705,8 @@ static ssize_t pktgen_if_write(struct file *file, if (!strcmp(name, "mpls")) { unsigned int n, cnt;

- len = get_labels(&user_buffer[i], pkt_dev); + max = count - i; + len = get_labels(&user_buffer[i], max, pkt_dev); if (len < 0) return len; i += len; @@ -1680,7 +1727,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "vlan_id")) { - len = num_arg(&user_buffer[i], DEC_4_DIGITS, &value); + max = min(DEC_4_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1707,7 +1755,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "vlan_p")) { - len = num_arg(&user_buffer[i], DEC_1_DIGITS, &value); + max = min(DEC_1_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1722,7 +1771,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "vlan_cfi")) { - len = num_arg(&user_buffer[i], DEC_1_DIGITS, &value); + max = min(DEC_1_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1737,7 +1787,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "svlan_id")) { - len = num_arg(&user_buffer[i], DEC_4_DIGITS, &value); + max = min(DEC_4_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1764,7 +1815,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "svlan_p")) { - len = num_arg(&user_buffer[i], DEC_1_DIGITS, &value); + max = min(DEC_1_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1779,7 +1831,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "svlan_cfi")) { - len = num_arg(&user_buffer[i], DEC_1_DIGITS, &value); + max = min(DEC_1_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1795,7 +1848,9 @@ static ssize_t pktgen_if_write(struct file *file,

if (!strcmp(name, "tos")) { __u32 tmp_value; - len = hex32_arg(&user_buffer[i], HEX_2_DIGITS, &tmp_value); + + max = min(HEX_2_DIGITS, count - i); + len = hex32_arg(&user_buffer[i], max, &tmp_value); if (len < 0) return len;

@@ -1811,7 +1866,9 @@ static ssize_t pktgen_if_write(struct file *file,

if (!strcmp(name, "traffic_class")) { __u32 tmp_value; - len = hex32_arg(&user_buffer[i], HEX_2_DIGITS, &tmp_value); + + max = min(HEX_2_DIGITS, count - i); + len = hex32_arg(&user_buffer[i], max, &tmp_value); if (len < 0) return len;

@@ -1826,7 +1883,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "skb_priority")) { - len = num_arg(&user_buffer[i], DEC_9_DIGITS, &value); + max = min(DEC_9_DIGITS, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;