diff options
| -rw-r--r-- | include/linux/netfilter/x_tables.h | 2 | ||||
| -rw-r--r-- | net/netfilter/x_tables.c | 30 | ||||
| -rw-r--r-- | net/netfilter/xt_hashlimit.c | 5 | ||||
| -rw-r--r-- | net/netfilter/xt_recent.c | 6 |
4 files changed, 38 insertions, 5 deletions
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 547a5846e..ee7b41359 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -248,6 +248,8 @@ extern int xt_check_match(struct xt_mtchk_param *, extern int xt_check_target(struct xt_tgchk_param *, unsigned int size, u_int8_t proto, bool inv_proto); +int xt_check_proc_name(const char *name, unsigned int size); + void *xt_copy_counters_from_user(const void __user *user, unsigned int len, struct xt_counters_info *info, bool compat); diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 1fd07fc69..121240b59 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -363,6 +363,36 @@ textify_hooks(char *buf, size_t size, unsigned int mask, uint8_t nfproto) return buf; } +/** + * xt_check_proc_name - check that name is suitable for /proc file creation + * + * @name: file name candidate + * @size: length of buffer + * + * some x_tables modules wish to create a file in /proc. + * This function makes sure that the name is suitable for this + * purpose, it checks that name is NUL terminated and isn't a 'special' + * name, like "..". + * + * returns negative number on error or 0 if name is useable. + */ +int xt_check_proc_name(const char *name, unsigned int size) +{ + if (name[0] == '\0') + return -EINVAL; + + if (strnlen(name, size) == size) + return -ENAMETOOLONG; + + if (strcmp(name, ".") == 0 || + strcmp(name, "..") == 0 || + strchr(name, '/')) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL(xt_check_proc_name); + int xt_check_match(struct xt_mtchk_param *par, unsigned int size, u_int8_t proto, bool inv_proto) { diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c index 9ff035c71..559ec7f90 100644 --- a/net/netfilter/xt_hashlimit.c +++ b/net/netfilter/xt_hashlimit.c @@ -664,8 +664,9 @@ static int hashlimit_mt_check(const struct xt_mtchk_param *par) if (info->cfg.gc_interval == 0 || info->cfg.expire == 0) return -EINVAL; - if (info->name[sizeof(info->name)-1] != '\0') - return -EINVAL; + ret = xt_check_proc_name(info->name, sizeof(info->name)); + if (ret) + return ret; if (par->family == NFPROTO_IPV4) { if (info->cfg.srcmask > 32 || info->cfg.dstmask > 32) return -EINVAL; diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c index 1e657cf71..db76207bc 100644 --- a/net/netfilter/xt_recent.c +++ b/net/netfilter/xt_recent.c @@ -358,9 +358,9 @@ static int recent_mt_check(const struct xt_mtchk_param *par, info->hit_count, ip_pkt_list_tot); return -EINVAL; } - if (info->name[0] == '\0' || - strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN) - return -EINVAL; + ret = xt_check_proc_name(info->name, sizeof(info->name)); + if (ret) + return ret; mutex_lock(&recent_mutex); t = recent_table_lookup(recent_net, info->name); |