[PATCH net-next v3 08/10] 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).

In hex32_arg(), num_arg(), strn_len() error out in case no characters are available (maxlen = 0), in num_arg() additional error out in case no valid character is parsed.

In get_labels() additional enable parsing labels up to MAX_IMIX_ENTRIES instead of (MAX_IMIX_ENTRIES - 1).

Additional remove some superfluous variable initializing and align some variable declarations to the most common pattern.

Signed-off-by: Peter Seiderer ps.report@gmx.net --- Changes v2 -> v3: - no changes

Changes v1 -> v2: - additional fix get_imix_entries() and get_labels() --- net/core/pktgen.c | 211 ++++++++++++++++++++++++++++++---------------- 1 file changed, 139 insertions(+), 72 deletions(-)

diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 55064713223e..6675375c052c 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -752,6 +752,9 @@ static int hex32_arg(const char __user *user_buffer, unsigned long maxlen, int i = 0; *num = 0;

+ if (!maxlen) + return -EINVAL; + for (; i < maxlen; i++) { int value; char c; @@ -799,6 +802,9 @@ static long num_arg(const char __user *user_buffer, unsigned long maxlen, int i; *num = 0;

+ if (!maxlen) + return -EINVAL; + for (i = 0; i < maxlen; i++) { char c; if (get_user(c, &user_buffer[i])) @@ -806,6 +812,9 @@ static long num_arg(const char __user *user_buffer, unsigned long maxlen, if ((c >= '0') && (c <= '9')) { *num *= 10; *num += c - '0'; + } else if (i == 0) { + // no valid character parsed, error out + return -EINVAL; } else break; } @@ -816,6 +825,9 @@ static int strn_len(const char __user * user_buffer, unsigned int maxlen) { int i;

+ if (!maxlen) + return -EINVAL; + for (i = 0; i < maxlen; i++) { char c; if (get_user(c, &user_buffer[i])) @@ -842,11 +854,10 @@ 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 ssize_t get_imix_entries(const char __user *buffer, + unsigned int maxlen, struct pktgen_dev *pkt_dev) { - const int max_digits = 10; - int i = 0; - long len; + int i = 0, max, len; char c;

pkt_dev->n_imix_entries = 0; @@ -858,10 +869,13 @@ static ssize_t get_imix_entries(const char __user *buffer, if (pkt_dev->n_imix_entries >= MAX_IMIX_ENTRIES) return -E2BIG;

- len = num_arg(&buffer[i], max_digits, &size); + max = min(10, 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 */ @@ -872,7 +886,8 @@ static ssize_t get_imix_entries(const char __user *buffer, if (size < 14 + 20 + 8) size = 14 + 20 + 8;

- len = num_arg(&buffer[i], max_digits, &weight); + max = min(10, maxlen - i); + len = num_arg(&buffer[i], max, &weight); if (len < 0) return len; if (weight <= 0) @@ -882,39 +897,45 @@ static ssize_t 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 ssize_t get_labels(const char __user *buffer, struct pktgen_dev *pkt_dev) +static ssize_t get_labels(const char __user *buffer, int maxlen, struct pktgen_dev *pkt_dev) { unsigned int n = 0; char c; - ssize_t i = 0; - int len; + int i = 0, max, len;

pkt_dev->nr_labels = 0; do { __u32 tmp; - len = hex32_arg(&buffer[i], 8, &tmp); + + if (n >= MAX_MPLS_LABELS) + return -E2BIG; + + max = min(8, 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++; - if (n >= MAX_MPLS_LABELS) - return -E2BIG; } while (c == ',');

pkt_dev->nr_labels = n; @@ -960,7 +981,6 @@ static ssize_t pktgen_if_write(struct file *file, char name[16], valstr[32]; unsigned long value = 0; char *pg_result = NULL; - int tmp = 0; char buf[128];

pg_result = &(pkt_dev->result[0]); @@ -970,17 +990,16 @@ static ssize_t pktgen_if_write(struct file *file, return -EINVAL; }

- max = count; - tmp = count_trail_chars(user_buffer, max); - if (tmp < 0) { + len = count_trail_chars(user_buffer, count); + if (len < 0) { pr_warn("illegal format\n"); - return tmp; + return len; } - i = tmp; + 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;

@@ -1008,7 +1027,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "min_pkt_size")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1025,7 +1045,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "max_pkt_size")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1044,7 +1065,8 @@ static ssize_t pktgen_if_write(struct file *file, /* Shortcut for min = max */

if (!strcmp(name, "pkt_size")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1064,7 +1086,8 @@ 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;

@@ -1075,7 +1098,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "debug")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1086,7 +1110,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "frags")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1096,7 +1121,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "delay")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1111,7 +1137,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "rate")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1126,7 +1153,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "ratep")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1141,7 +1169,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "udp_src_min")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1154,7 +1183,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "udp_dst_min")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1167,7 +1197,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "udp_src_max")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1180,7 +1211,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "udp_dst_max")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1193,7 +1225,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "clone_skb")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, 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 @@ -1214,7 +1247,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "count")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1225,7 +1259,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "src_mac_count")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1239,7 +1274,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "dst_mac_count")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1253,7 +1289,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "burst")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1272,7 +1309,8 @@ static ssize_t pktgen_if_write(struct file *file, return count; } if (!strcmp(name, "node")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1293,11 +1331,12 @@ 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; @@ -1333,11 +1372,12 @@ 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; @@ -1382,7 +1422,8 @@ 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;

@@ -1402,7 +1443,8 @@ 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;

@@ -1422,7 +1464,8 @@ 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;

@@ -1445,7 +1488,8 @@ 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;

@@ -1467,7 +1511,8 @@ 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;

@@ -1488,7 +1533,8 @@ 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;

@@ -1511,7 +1557,8 @@ 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;

@@ -1531,7 +1578,8 @@ 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;

@@ -1551,7 +1599,8 @@ 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;

@@ -1568,7 +1617,8 @@ 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;

@@ -1592,7 +1642,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "flows")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1606,7 +1657,8 @@ static ssize_t pktgen_if_write(struct file *file, } #ifdef CONFIG_XFRM if (!strcmp(name, "spi")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1617,7 +1669,8 @@ static ssize_t pktgen_if_write(struct file *file, } #endif if (!strcmp(name, "flowlen")) { - len = num_arg(&user_buffer[i], 10, &value); + max = min(10, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1628,7 +1681,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "queue_map_min")) { - len = num_arg(&user_buffer[i], 5, &value); + max = min(5, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1639,7 +1693,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "queue_map_max")) { - len = num_arg(&user_buffer[i], 5, &value); + max = min(5, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1652,7 +1707,8 @@ 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; @@ -1673,7 +1729,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "vlan_id")) { - len = num_arg(&user_buffer[i], 4, &value); + max = min(4, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1700,7 +1757,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "vlan_p")) { - len = num_arg(&user_buffer[i], 1, &value); + max = min(1, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1715,7 +1773,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "vlan_cfi")) { - len = num_arg(&user_buffer[i], 1, &value); + max = min(1, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1730,7 +1789,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "svlan_id")) { - len = num_arg(&user_buffer[i], 4, &value); + max = min(4, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1757,7 +1817,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "svlan_p")) { - len = num_arg(&user_buffer[i], 1, &value); + max = min(1, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1772,7 +1833,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "svlan_cfi")) { - len = num_arg(&user_buffer[i], 1, &value); + max = min(1, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;

@@ -1787,8 +1849,10 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "tos")) { - __u32 tmp_value = 0; - len = hex32_arg(&user_buffer[i], 2, &tmp_value); + __u32 tmp_value; + + max = min(2, count - i); + len = hex32_arg(&user_buffer[i], max, &tmp_value); if (len < 0) return len;

@@ -1803,8 +1867,10 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "traffic_class")) { - __u32 tmp_value = 0; - len = hex32_arg(&user_buffer[i], 2, &tmp_value); + __u32 tmp_value; + + max = min(2, count - i); + len = hex32_arg(&user_buffer[i], max, &tmp_value); if (len < 0) return len;

@@ -1819,7 +1885,8 @@ static ssize_t pktgen_if_write(struct file *file, }

if (!strcmp(name, "skb_priority")) { - len = num_arg(&user_buffer[i], 9, &value); + max = min(9, count - i); + len = num_arg(&user_buffer[i], max, &value); if (len < 0) return len;