diff options
Diffstat (limited to 'lib/nlattr.c')
| -rw-r--r-- | lib/nlattr.c | 74 |
1 files changed, 71 insertions, 3 deletions
diff --git a/lib/nlattr.c b/lib/nlattr.c index fb52435be42d..8bf78b4b78f0 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * NETLINK Netlink attributes * @@ -14,19 +15,47 @@ #include <linux/types.h> #include <net/netlink.h> -static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = { +/* for these data types attribute length must be exactly given size */ +static const u8 nla_attr_len[NLA_TYPE_MAX+1] = { [NLA_U8] = sizeof(u8), [NLA_U16] = sizeof(u16), [NLA_U32] = sizeof(u32), [NLA_U64] = sizeof(u64), - [NLA_MSECS] = sizeof(u64), - [NLA_NESTED] = NLA_HDRLEN, [NLA_S8] = sizeof(s8), [NLA_S16] = sizeof(s16), [NLA_S32] = sizeof(s32), [NLA_S64] = sizeof(s64), }; +static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = { + [NLA_MSECS] = sizeof(u64), + [NLA_NESTED] = NLA_HDRLEN, +}; + +static int validate_nla_bitfield32(const struct nlattr *nla, + u32 *valid_flags_allowed) +{ + const struct nla_bitfield32 *bf = nla_data(nla); + u32 *valid_flags_mask = valid_flags_allowed; + + if (!valid_flags_allowed) + return -EINVAL; + + /*disallow invalid bit selector */ + if (bf->selector & ~*valid_flags_mask) + return -EINVAL; + + /*disallow invalid bit values */ + if (bf->value & ~*valid_flags_mask) + return -EINVAL; + + /*disallow valid bit values that are not selected*/ + if (bf->value & ~bf->selector) + return -EINVAL; + + return 0; +} + static int validate_nla(const struct nlattr *nla, int maxtype, const struct nla_policy *policy) { @@ -40,12 +69,25 @@ static int validate_nla(const struct nlattr *nla, int maxtype, BUG_ON(pt->type > NLA_TYPE_MAX); + /* for data types NLA_U* and NLA_S* require exact length */ + if (nla_attr_len[pt->type]) { + if (attrlen != nla_attr_len[pt->type]) + return -ERANGE; + return 0; + } + switch (pt->type) { case NLA_FLAG: if (attrlen > 0) return -ERANGE; break; + case NLA_BITFIELD32: + if (attrlen != sizeof(struct nla_bitfield32)) + return -ERANGE; + + return validate_nla_bitfield32(nla, pt->validation_data); + case NLA_NUL_STRING: if (pt->len) minlen = min_t(int, attrlen, pt->len + 1); @@ -160,6 +202,8 @@ nla_policy_len(const struct nla_policy *p, int n) for (i = 0; i < n; i++, p++) { if (p->len) len += nla_total_size(p->len); + else if (nla_attr_len[p->type]) + len += nla_total_size(nla_attr_len[p->type]); else if (nla_attr_minlen[p->type]) len += nla_total_size(nla_attr_minlen[p->type]); } @@ -272,6 +316,30 @@ size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize) EXPORT_SYMBOL(nla_strlcpy); /** + * nla_strdup - Copy string attribute payload into a newly allocated buffer + * @nla: attribute to copy the string from + * @flags: the type of memory to allocate (see kmalloc). + * + * Returns a pointer to the allocated buffer or NULL on error. + */ +char *nla_strdup(const struct nlattr *nla, gfp_t flags) +{ + size_t srclen = nla_len(nla); + char *src = nla_data(nla), *dst; + + if (srclen > 0 && src[srclen - 1] == '\0') + srclen--; + + dst = kmalloc(srclen + 1, flags); + if (dst != NULL) { + memcpy(dst, src, srclen); + dst[srclen] = '\0'; + } + return dst; +} +EXPORT_SYMBOL(nla_strdup); + +/** * nla_memcpy - Copy a netlink attribute into another memory area * @dest: where to copy to memcpy * @src: netlink attribute to copy from |