[PATCH net-next v8 5/8] 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 Reviewed-by: Simon Horman horms@kernel.org --- Changes v7 -> v8 - rebased on actual net-next/main - no changes

Changes v6 -> v7 - rebased on actual net-next/main - no changes

Changes v5 -> v6 - adjust to dropped patch 'net: pktgen: use defines for the various dec/hex number parsing digits lengths'

Changes v4 -> v5 - split up patchset into part i/ii (suggested by Simon Horman) - add rev-by Simon Horman

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 | 178 ++++++++++++++++++++++++++++++---------------- 1 file changed, 118 insertions(+), 60 deletions(-)

diff --git a/net/core/pktgen.c b/net/core/pktgen.c index def35a734d9d..f4f9c9d83694 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -840,10 +840,10 @@ static ssize_t strn_len(const char __user *user_buffer, size_t maxlen) * "size1,weight_1 size2,weight_2 ... size_n,weight_n" for example. */ static ssize_t get_imix_entries(const char __user *buffer, + size_t maxlen, struct pktgen_dev *pkt_dev) { - const size_t max_digits = 10; - size_t i = 0; + size_t i = 0, max; ssize_t len; char c;

@@ -856,10 +856,13 @@ 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 */ @@ -870,7 +873,8 @@ 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) @@ -880,20 +884,23 @@ 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, + size_t maxlen, struct pktgen_dev *pkt_dev) { unsigned int n = 0; - size_t i = 0; + size_t i = 0, max; ssize_t len; char c;

@@ -904,17 +911,20 @@ static ssize_t get_labels(const char __user *buffer, struct pktgen_dev *pkt_dev) if (n >= MAX_MPLS_LABELS) return -E2BIG;

- len = hex32_arg(&buffer[i], 8, &tmp); + 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++; } while (c == ',');

pkt_dev->nr_labels = n; @@ -979,8 +989,8 @@ 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;

@@ -1008,7 +1018,8 @@ 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 +1036,8 @@ 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 +1056,8 @@ 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 +1077,8 @@ 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 +1089,8 @@ 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 +1101,8 @@ 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 +1112,8 @@ 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 +1128,8 @@ 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 +1144,8 @@ 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 +1160,8 @@ 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 +1174,8 @@ 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 +1188,8 @@ 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 +1202,8 @@ 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 +1216,8 @@ 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 +1238,8 @@ 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 +1250,8 @@ 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 +1265,8 @@ 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 +1280,8 @@ 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 +1300,8 @@ 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 +1322,12 @@ 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 +1363,12 @@ 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 +1413,8 @@ 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 +1434,8 @@ 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 +1455,8 @@ 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 +1479,8 @@ 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 +1502,8 @@ 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 +1524,8 @@ 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 +1548,8 @@ 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 +1569,8 @@ 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 +1590,8 @@ 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 +1608,8 @@ 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 +1633,8 @@ 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 +1648,8 @@ 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 +1660,8 @@ 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 +1672,8 @@ 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 +1684,8 @@ 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 +1698,8 @@ 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 +1720,8 @@ 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 +1748,8 @@ 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 +1764,8 @@ 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 +1780,8 @@ 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 +1808,8 @@ 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 +1824,8 @@ 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;

@@ -1788,7 +1841,9 @@ static ssize_t pktgen_if_write(struct file *file,

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

@@ -1804,7 +1859,9 @@ static ssize_t pktgen_if_write(struct file *file,

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

@@ -1819,7 +1876,8 @@ 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;