[PATCH 06/18] backport: Extend netlink parsing with strict validation
Hauke Mehrtens <[email protected]>
| Newsgroups | org.kernel.vger.backports |
|---|---|
| Message-ID | <[email protected]> |
From: Johannes Berg <[email protected]> This extends the backported netlink handling with strict parsing. the struct gen_ops now supports the validate member and does the validation inside the backport layer. This is needed to use backports with kernel 5.2. [Hauke: Remove nla_validate_nested()] [Hauke: Support struct genl_ops on older kernel versions] Signed-off-by: Hauke Mehrtens <[email protected]> --- backport/backport-include/net/genetlink.h | 62 +++- backport/backport-include/net/netlink.h | 341 +++++++++++++----- backport/compat/Kconfig | 5 + backport/compat/Makefile | 4 +- .../{backport-4.20.c => backport-5.2.c} | 216 ++++++++--- backport/compat/backport-genetlink.c | 26 +- 6 files changed, 491 insertions(+), 163 deletions(-) rename backport/compat/{backport-4.20.c => backport-5.2.c} (58%) diff --git a/backport/backport-include/net/genetlink.h b/backport/backport-include/net/genetlink.h index 84011e72..772f10f0 100644 --- a/backport/backport-include/net/genetlink.h +++ b/backport/backport-include/net/genetlink.h @@ -91,12 +91,71 @@ void backport_genl_dump_check_consistent(struct netlink_callback *cb, #endif #endif /* LINUX_VERSION_IS_LESS(4,15,0) */ -#if LINUX_VERSION_IS_LESS(4,20,0) +#if LINUX_VERSION_IS_LESS(5,2,0) +enum genl_validate_flags { + GENL_DONT_VALIDATE_STRICT = BIT(0), + GENL_DONT_VALIDATE_DUMP = BIT(1), + GENL_DONT_VALIDATE_DUMP_STRICT = BIT(2), +}; + +#if LINUX_VERSION_IS_GEQ(3,13,0) +struct backport_genl_ops { + void *__dummy_was_policy_must_be_null; + int (*doit)(struct sk_buff *skb, + struct genl_info *info); +#if LINUX_VERSION_IS_GEQ(4,5,0) || \ + LINUX_VERSION_IN_RANGE(4,4,104, 4,5,0) || \ + LINUX_VERSION_IN_RANGE(4,1,48, 4,2,0) || \ + LINUX_VERSION_IN_RANGE(3,18,86, 3,19,0) + int (*start)(struct netlink_callback *cb); +#endif + int (*dumpit)(struct sk_buff *skb, + struct netlink_callback *cb); + int (*done)(struct netlink_callback *cb); + u8 cmd; + u8 internal_flags; + u8 flags; + u8 validate; +}; +#else +struct backport_genl_ops { + u8 cmd; + u8 internal_flags; + unsigned int flags; + void *__dummy_was_policy_must_be_null; + int (*doit)(struct sk_buff *skb, + struct genl_info *info); + int (*dumpit)(struct sk_buff *skb, + struct netlink_callback *cb); + int (*done)(struct netlink_callback *cb); + struct list_head ops_list; + u8 validate; +}; +#endif + static inline int __real_backport_genl_register_family(struct genl_family *family) { +#define OPS_VALIDATE(f) \ + BUILD_BUG_ON(offsetof(struct genl_ops, f) != \ + offsetof(struct backport_genl_ops, f)) + OPS_VALIDATE(doit); +#if LINUX_VERSION_IS_GEQ(4,5,0) || \ + LINUX_VERSION_IN_RANGE(4,4,104, 4,5,0) || \ + LINUX_VERSION_IN_RANGE(4,1,48, 4,2,0) || \ + LINUX_VERSION_IN_RANGE(3,18,86, 3,19,0) + OPS_VALIDATE(start); +#endif + OPS_VALIDATE(dumpit); + OPS_VALIDATE(done); + OPS_VALIDATE(cmd); + OPS_VALIDATE(internal_flags); + OPS_VALIDATE(flags); + return genl_register_family(family); } +#define genl_ops backport_genl_ops + static inline int __real_backport_genl_unregister_family(struct genl_family *family) { @@ -115,6 +174,7 @@ struct backport_genl_family { unsigned int maxattr; bool netnsok; bool parallel_ops; + const struct nla_policy *policy; int (*pre_doit)(__genl_const struct genl_ops *ops, struct sk_buff *skb, struct genl_info *info); diff --git a/backport/backport-include/net/netlink.h b/backport/backport-include/net/netlink.h index d8237f10..4d73c57f 100644 --- a/backport/backport-include/net/netlink.h +++ b/backport/backport-include/net/netlink.h @@ -4,20 +4,7 @@ #include <linux/version.h> #include <linux/in6.h> -#if LINUX_VERSION_IS_LESS(5,1,0) -#undef NLA_POLICY_NESTED -#undef NLA_POLICY_NESTED_ARRAY -#define _NLA_POLICY_NESTED(maxattr, policy) \ - { .type = NLA_NESTED, .validation_data = policy, .len = maxattr } -#define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ - { .type = NLA_NESTED_ARRAY, .validation_data = policy, .len = maxattr } -#define NLA_POLICY_NESTED(policy) \ - _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy) -#define NLA_POLICY_NESTED_ARRAY(policy) \ - _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy) -#endif /* < 5.1 */ - -#if LINUX_VERSION_IS_LESS(4,20,0) +#if LINUX_VERSION_IS_LESS(5,2,0) /* can't backport using the enum - need to override */ #define NLA_UNSPEC 0 #define NLA_U8 1 @@ -39,17 +26,10 @@ #define NLA_REJECT 17 #define NLA_EXACT_LEN 18 #define NLA_EXACT_LEN_WARN 19 -#define __NLA_TYPE_MAX 20 +#define NLA_MIN_LEN 20 +#define __NLA_TYPE_MAX 21 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) -enum nla_policy_validation { - NLA_VALIDATE_NONE, - NLA_VALIDATE_RANGE, - NLA_VALIDATE_MIN, - NLA_VALIDATE_MAX, - NLA_VALIDATE_FUNCTION, -}; - struct backport_nla_policy { u8 type; u8 validation_type; @@ -61,77 +41,169 @@ struct backport_nla_policy { }; int (*validate)(const struct nlattr *attr, struct netlink_ext_ack *extack); + u16 strict_start_type; }; }; #define nla_policy backport_nla_policy -#define NLA_POLICY_EXACT_LEN(_len) { .type = NLA_EXACT_LEN, .len = _len } -#define NLA_POLICY_EXACT_LEN_WARN(_len) { .type = NLA_EXACT_LEN_WARN, \ - .len = _len } +#define nla_nest_start_noflag LINUX_BACKPORT(nla_nest_start_noflag) +static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb, + int attrtype) +{ + struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); -#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN) -#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN) + if (nla_put(skb, attrtype, 0, NULL) < 0) + return NULL; -#define __NLA_ENSURE(condition) (sizeof(char[1 - 2*!(condition)]) - 1) -#define NLA_ENSURE_INT_TYPE(tp) \ - (__NLA_ENSURE(tp == NLA_S8 || tp == NLA_U8 || \ - tp == NLA_S16 || tp == NLA_U16 || \ - tp == NLA_S32 || tp == NLA_U32 || \ - tp == NLA_S64 || tp == NLA_U64) + tp) -#define NLA_ENSURE_NO_VALIDATION_PTR(tp) \ - (__NLA_ENSURE(tp != NLA_BITFIELD32 && \ - tp != NLA_REJECT && \ - tp != NLA_NESTED && \ - tp != NLA_NESTED_ARRAY) + tp) + return start; +} -#define NLA_POLICY_RANGE(tp, _min, _max) { \ - .type = NLA_ENSURE_INT_TYPE(tp), \ - .validation_type = NLA_VALIDATE_RANGE, \ - .min = _min, \ - .max = _max \ +#define nla_nest_start LINUX_BACKPORT(nla_nest_start) +static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) +{ + return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED); } -#define NLA_POLICY_MIN(tp, _min) { \ - .type = NLA_ENSURE_INT_TYPE(tp), \ - .validation_type = NLA_VALIDATE_MIN, \ - .min = _min, \ +enum netlink_validation { + NL_VALIDATE_LIBERAL = 0, + NL_VALIDATE_TRAILING = BIT(0), + NL_VALIDATE_MAXTYPE = BIT(1), + NL_VALIDATE_UNSPEC = BIT(2), + NL_VALIDATE_STRICT_ATTRS = BIT(3), + NL_VALIDATE_NESTED = BIT(4), +}; + +#define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\ + NL_VALIDATE_MAXTYPE) +#define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\ + NL_VALIDATE_MAXTYPE |\ + NL_VALIDATE_UNSPEC |\ + NL_VALIDATE_STRICT_ATTRS |\ + NL_VALIDATE_NESTED) + +#define __nla_validate LINUX_BACKPORT(__nla_validate) +int __nla_validate(const struct nlattr *head, int len, int maxtype, + const struct nla_policy *policy, unsigned int validate, + struct netlink_ext_ack *extack); +#define __nla_parse LINUX_BACKPORT(__nla_parse) +int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, + int len, const struct nla_policy *policy, unsigned int validate, + struct netlink_ext_ack *extack); + +#define nla_policy_len LINUX_BACKPORT(nla_policy_len) +int nla_policy_len(const struct nla_policy *, int); + +#define nla_parse LINUX_BACKPORT(nla_parse) +static inline int nla_parse(struct nlattr **tb, int maxtype, + const struct nlattr *head, int len, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + return __nla_parse(tb, maxtype, head, len, policy, + NL_VALIDATE_STRICT, extack); } -#define NLA_POLICY_MAX(tp, _max) { \ - .type = NLA_ENSURE_INT_TYPE(tp), \ - .validation_type = NLA_VALIDATE_MAX, \ - .max = _max, \ +#define nla_parse_deprecated LINUX_BACKPORT(nla_parse_deprecated) +static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype, + const struct nlattr *head, int len, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + return __nla_parse(tb, maxtype, head, len, policy, + NL_VALIDATE_LIBERAL, extack); } -#define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \ - .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \ - .validation_type = NLA_VALIDATE_FUNCTION, \ - .validate = fn, \ - .len = __VA_ARGS__ + 0, \ +#define nla_parse_deprecated_strict LINUX_BACKPORT(nla_parse_deprecated_strict) +static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype, + const struct nlattr *head, + int len, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + return __nla_parse(tb, maxtype, head, len, policy, + NL_VALIDATE_DEPRECATED_STRICT, extack); } -#define nla_validate LINUX_BACKPORT(nla_validate) -int nla_validate(const struct nlattr *head, int len, int maxtype, - const struct nla_policy *policy, - struct netlink_ext_ack *extack); -#define nla_parse LINUX_BACKPORT(nla_parse) -int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, - int len, const struct nla_policy *policy, - struct netlink_ext_ack *extack); -#define nla_policy_len LINUX_BACKPORT(nla_policy_len) -int nla_policy_len(const struct nla_policy *, int); +#define __nlmsg_parse LINUX_BACKPORT(__nlmsg_parse) +static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, + struct nlattr *tb[], int maxtype, + const struct nla_policy *policy, + unsigned int validate, + struct netlink_ext_ack *extack) +{ + if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) { + NL_SET_ERR_MSG(extack, "Invalid header length"); + return -EINVAL; + } + + return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), + nlmsg_attrlen(nlh, hdrlen), policy, validate, + extack); +} #define nlmsg_parse LINUX_BACKPORT(nlmsg_parse) static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, struct nlattr *tb[], int maxtype, const struct nla_policy *policy, struct netlink_ext_ack *extack) +{ + return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), + nlmsg_attrlen(nlh, hdrlen), policy, + NL_VALIDATE_STRICT, extack); +} + +#define nlmsg_parse_deprecated LINUX_BACKPORT(nlmsg_parse_deprecated) +static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen, + struct nlattr *tb[], int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, + NL_VALIDATE_LIBERAL, extack); +} + +#define nlmsg_parse_deprecated_strict LINUX_BACKPORT(nlmsg_parse_deprecated_strict) +static inline int +nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen, + struct nlattr *tb[], int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy, + NL_VALIDATE_DEPRECATED_STRICT, extack); +} + +#define nla_validate_deprecated LINUX_BACKPORT(nla_validate_deprecated) +static inline int nla_validate_deprecated(const struct nlattr *head, int len, + int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL, + extack); +} + +#define nla_validate LINUX_BACKPORT(nla_validate) +static inline int nla_validate(const struct nlattr *head, int len, int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT, + extack); +} + +#define nlmsg_validate_deprecated LINUX_BACKPORT(nlmsg_validate_deprecated) +static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh, + int hdrlen, int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) { if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) return -EINVAL; - return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), - nlmsg_attrlen(nlh, hdrlen), policy, extack); + return __nla_validate(nlmsg_attrdata(nlh, hdrlen), + nlmsg_attrlen(nlh, hdrlen), maxtype, + policy, NL_VALIDATE_LIBERAL, extack); } #define nlmsg_validate LINUX_BACKPORT(nlmsg_validate) @@ -143,9 +215,9 @@ static inline int nlmsg_validate(const struct nlmsghdr *nlh, if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) return -EINVAL; - return nla_validate(nlmsg_attrdata(nlh, hdrlen), - nlmsg_attrlen(nlh, hdrlen), maxtype, policy, - extack); + return __nla_validate(nlmsg_attrdata(nlh, hdrlen), + nlmsg_attrlen(nlh, hdrlen), maxtype, + policy, NL_VALIDATE_STRICT, extack); } #define nla_parse_nested LINUX_BACKPORT(nla_parse_nested) @@ -154,17 +226,111 @@ static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, const struct nla_policy *policy, struct netlink_ext_ack *extack) { - return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, - extack); + if (!(nla->nla_type & NLA_F_NESTED)) { + NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing"); + return -EINVAL; + } + + return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, + NL_VALIDATE_STRICT, extack); } -#define nla_validate_nested LINUX_BACKPORT(nla_validate_nested) -static inline int nla_validate_nested(const struct nlattr *start, int maxtype, - const struct nla_policy *policy, - struct netlink_ext_ack *extack) +#define nla_parse_nested_deprecated LINUX_BACKPORT(nla_parse_nested_deprecated) +static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype, + const struct nlattr *nla, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) { - return nla_validate(nla_data(start), nla_len(start), maxtype, policy, - extack); + return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy, + NL_VALIDATE_LIBERAL, extack); +} + +#define __nla_validate_nested LINUX_BACKPORT(__nla_validate_nested) +static inline int __nla_validate_nested(const struct nlattr *start, int maxtype, + const struct nla_policy *policy, + unsigned int validate, + struct netlink_ext_ack *extack) +{ + return __nla_validate(nla_data(start), nla_len(start), maxtype, policy, + validate, extack); +} + +#define nla_validate_nested_deprecated LINUX_BACKPORT(nla_validate_nested_deprecated) +static inline int +nla_validate_nested_deprecated(const struct nlattr *start, int maxtype, + const struct nla_policy *policy, + struct netlink_ext_ack *extack) +{ + return __nla_validate_nested(start, maxtype, policy, + NL_VALIDATE_LIBERAL, extack); +} +#endif /* < 5.2 */ + +#if LINUX_VERSION_IS_LESS(5,1,0) +#undef NLA_POLICY_NESTED +#undef NLA_POLICY_NESTED_ARRAY +#define _NLA_POLICY_NESTED(maxattr, policy) \ + { .type = NLA_NESTED, .validation_data = policy, .len = maxattr } +#define _NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ + { .type = NLA_NESTED_ARRAY, .validation_data = policy, .len = maxattr } +#define NLA_POLICY_NESTED(policy) \ + _NLA_POLICY_NESTED(ARRAY_SIZE(policy) - 1, policy) +#define NLA_POLICY_NESTED_ARRAY(policy) \ + _NLA_POLICY_NESTED_ARRAY(ARRAY_SIZE(policy) - 1, policy) +#endif /* < 5.1 */ + +#if LINUX_VERSION_IS_LESS(4,20,0) +enum nla_policy_validation { + NLA_VALIDATE_NONE, + NLA_VALIDATE_RANGE, + NLA_VALIDATE_MIN, + NLA_VALIDATE_MAX, + NLA_VALIDATE_FUNCTION, +}; + +#define NLA_POLICY_EXACT_LEN(_len) { .type = NLA_EXACT_LEN, .len = _len } +#define NLA_POLICY_EXACT_LEN_WARN(_len) { .type = NLA_EXACT_LEN_WARN, \ + .len = _len } + +#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN) +#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN) + +#define __NLA_ENSURE(condition) (sizeof(char[1 - 2*!(condition)]) - 1) +#define NLA_ENSURE_INT_TYPE(tp) \ + (__NLA_ENSURE(tp == NLA_S8 || tp == NLA_U8 || \ + tp == NLA_S16 || tp == NLA_U16 || \ + tp == NLA_S32 || tp == NLA_U32 || \ + tp == NLA_S64 || tp == NLA_U64) + tp) +#define NLA_ENSURE_NO_VALIDATION_PTR(tp) \ + (__NLA_ENSURE(tp != NLA_BITFIELD32 && \ + tp != NLA_REJECT && \ + tp != NLA_NESTED && \ + tp != NLA_NESTED_ARRAY) + tp) + +#define NLA_POLICY_RANGE(tp, _min, _max) { \ + .type = NLA_ENSURE_INT_TYPE(tp), \ + .validation_type = NLA_VALIDATE_RANGE, \ + .min = _min, \ + .max = _max \ +} + +#define NLA_POLICY_MIN(tp, _min) { \ + .type = NLA_ENSURE_INT_TYPE(tp), \ + .validation_type = NLA_VALIDATE_MIN, \ + .min = _min, \ +} + +#define NLA_POLICY_MAX(tp, _max) { \ + .type = NLA_ENSURE_INT_TYPE(tp), \ + .validation_type = NLA_VALIDATE_MAX, \ + .max = _max, \ +} + +#define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \ + .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \ + .validation_type = NLA_VALIDATE_FUNCTION, \ + .validate = fn, \ + .len = __VA_ARGS__ + 0, \ } #endif /* < 4.20 */ @@ -255,21 +421,6 @@ static inline int _nla_parse_nested4(struct nlattr *tb[], int maxtype, #undef nla_parse_nested #define nla_parse_nested(...) \ macro_dispatcher(_nla_parse_nested, __VA_ARGS__)(__VA_ARGS__) - -static inline int _nla_validate_nested4(const struct nlattr *start, int maxtype, - const struct nla_policy *policy, - struct netlink_ext_ack *extack) -{ - return nla_validate_nested(start, maxtype, policy, extack); -} -static inline int _nla_validate_nested3(const struct nlattr *start, int maxtype, - const struct nla_policy *policy) -{ - return nla_validate_nested(start, maxtype, policy, NULL); -} -#undef nla_validate_nested -#define nla_validate_nested(...) \ - macro_dispatcher(_nla_validate_nested, __VA_ARGS__)(__VA_ARGS__) #endif /* LINUX_VERSION_IS_LESS(4,12,0) */ #if LINUX_VERSION_IS_LESS(3,7,0) diff --git a/backport/compat/Kconfig b/backport/compat/Kconfig index 20f34f1a..1d85a5da 100644 --- a/backport/compat/Kconfig +++ b/backport/compat/Kconfig @@ -62,6 +62,11 @@ config BP_MODULES This symbol is necessary for the newer kconf tool, it looks for the "option modules" to control the 'm' state. +config BPAUTO_BUILD_NLATTR + def_bool y + depends on KERNEL_5_2 + #c-file lib/nlattr.c + config BPAUTO_BUILD_CORDIC tristate depends on !CORDIC diff --git a/backport/compat/Makefile b/backport/compat/Makefile index 99b52faa..e92e3120 100644 --- a/backport/compat/Makefile +++ b/backport/compat/Makefile @@ -37,9 +37,7 @@ compat-$(CPTCFG_KERNEL_4_7) += backport-4.7.o compat-$(CPTCFG_KERNEL_4_8) += backport-4.8.o compat-$(CPTCFG_KERNEL_4_10) += backport-4.10.o compat-$(CPTCFG_KERNEL_4_18) += backport-4.18.o -compat-$(CPTCFG_KERNEL_4_20) += backport-4.20.o - -compat-$(CPTCFG_KERNEL_4_20) += backport-genetlink.o +compat-$(CPTCFG_KERNEL_5_2) += backport-5.2.o backport-genetlink.o compat-$(CPTCFG_BPAUTO_BUILD_SYSTEM_DATA_VERIFICATION) += verification/verify.o compat-$(CPTCFG_BPAUTO_BUILD_SYSTEM_DATA_VERIFICATION) += verification/pkcs7.asn1.o diff --git a/backport/compat/backport-4.20.c b/backport/compat/backport-5.2.c similarity index 58% rename from backport/compat/backport-4.20.c rename to backport/compat/backport-5.2.c index e26f3b52..5624d5fa 100644 --- a/backport/compat/backport-4.20.c +++ b/backport/compat/backport-5.2.c @@ -1,19 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0 /* - * Copyright (C) 2018 Intel Corporation + * NETLINK Netlink attributes * - * Backport functionality introduced in Linux 4.20. - * This is basically upstream lib/nlattr.c. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. + * Authors: Thomas Graf <[email protected]> + * Alexey Kuznetsov <[email protected]> */ -#include <linux/kernel.h> + #include <linux/export.h> +#include <linux/kernel.h> #include <linux/errno.h> +#include <linux/jiffies.h> +#include <linux/skbuff.h> +#include <linux/string.h> #include <linux/types.h> #include <net/netlink.h> +/* For these data types, attribute length should be exactly the given + * size. However, to maintain compatibility with broken commands, if the + * attribute length does not match the expected size a warning is emitted + * to the user that the command is sending invalid data and needs to be fixed. + */ static const u8 nla_attr_len[NLA_TYPE_MAX+1] = { [NLA_U8] = sizeof(u8), [NLA_U16] = sizeof(u16), @@ -63,7 +69,8 @@ static int validate_nla_bitfield32(const struct nlattr *nla, static int nla_validate_array(const struct nlattr *head, int len, int maxtype, const struct nla_policy *policy, - struct netlink_ext_ack *extack) + struct netlink_ext_ack *extack, + unsigned int validate) { const struct nlattr *entry; int rem; @@ -80,8 +87,8 @@ static int nla_validate_array(const struct nlattr *head, int len, int maxtype, return -ERANGE; } - ret = nla_validate(nla_data(entry), nla_len(entry), - maxtype, policy, extack); + ret = __nla_validate(nla_data(entry), nla_len(entry), + maxtype, policy, validate, extack); if (ret < 0) return ret; } @@ -148,13 +155,17 @@ static int nla_validate_int_range(const struct nla_policy *pt, } static int validate_nla(const struct nlattr *nla, int maxtype, - const struct nla_policy *policy, + const struct nla_policy *policy, unsigned int validate, struct netlink_ext_ack *extack) { + u16 strict_start_type = policy[0].strict_start_type; const struct nla_policy *pt; int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla); int err = -ERANGE; + if (strict_start_type && type >= strict_start_type) + validate |= NL_VALIDATE_STRICT; + if (type <= 0 || type > maxtype) return 0; @@ -166,6 +177,26 @@ static int validate_nla(const struct nlattr *nla, int maxtype, (pt->type == NLA_EXACT_LEN_WARN && attrlen != pt->len)) { pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n", current->comm, type); + if (validate & NL_VALIDATE_STRICT_ATTRS) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "invalid attribute length"); + return -EINVAL; + } + } + + if (validate & NL_VALIDATE_NESTED) { + if ((pt->type == NLA_NESTED || pt->type == NLA_NESTED_ARRAY) && + !(nla->nla_type & NLA_F_NESTED)) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "NLA_F_NESTED is missing"); + return -EINVAL; + } + if (pt->type != NLA_NESTED && pt->type != NLA_NESTED_ARRAY && + pt->type != NLA_UNSPEC && (nla->nla_type & NLA_F_NESTED)) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "NLA_F_NESTED not expected"); + return -EINVAL; + } } switch (pt->type) { @@ -238,8 +269,9 @@ static int validate_nla(const struct nlattr *nla, int maxtype, if (attrlen < NLA_HDRLEN) goto out_err; if (pt->validation_data) { - err = nla_validate(nla_data(nla), nla_len(nla), pt->len, - pt->validation_data, extack); + err = __nla_validate(nla_data(nla), nla_len(nla), pt->len, + pt->validation_data, validate, + extack); if (err < 0) { /* * return directly to preserve the inner @@ -262,7 +294,7 @@ static int validate_nla(const struct nlattr *nla, int maxtype, err = nla_validate_array(nla_data(nla), nla_len(nla), pt->len, pt->validation_data, - extack); + extack, validate); if (err < 0) { /* * return directly to preserve the inner @@ -272,10 +304,23 @@ static int validate_nla(const struct nlattr *nla, int maxtype, } } break; + + case NLA_UNSPEC: + if (validate & NL_VALIDATE_UNSPEC) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "Unsupported attribute"); + return -EINVAL; + } + /* fall through */ + case NLA_MIN_LEN: + if (attrlen < pt->len) + goto out_err; + break; + default: if (pt->len) minlen = pt->len; - else if (pt->type != NLA_UNSPEC) + else minlen = nla_attr_minlen[pt->type]; if (attrlen < minlen) @@ -309,25 +354,90 @@ out_err: return err; } -int backport_nla_validate(const struct nlattr *head, int len, int maxtype, - const struct nla_policy *policy, - struct netlink_ext_ack *extack) +static int __nla_validate_parse(const struct nlattr *head, int len, int maxtype, + const struct nla_policy *policy, + unsigned int validate, + struct netlink_ext_ack *extack, + struct nlattr **tb) { const struct nlattr *nla; int rem; + if (tb) + memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); + nla_for_each_attr(nla, head, len, rem) { - int err = validate_nla(nla, maxtype, policy, extack); + u16 type = nla_type(nla); - if (err < 0) - return err; + if (type == 0 || type > maxtype) { + if (validate & NL_VALIDATE_MAXTYPE) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "Unknown attribute type"); + return -EINVAL; + } + continue; + } + if (policy) { + int err = validate_nla(nla, maxtype, policy, + validate, extack); + + if (err < 0) + return err; + } + + if (tb) + tb[type] = (struct nlattr *)nla; + } + + if (unlikely(rem > 0)) { + pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n", + rem, current->comm); + NL_SET_ERR_MSG(extack, "bytes leftover after parsing attributes"); + if (validate & NL_VALIDATE_TRAILING) + return -EINVAL; } return 0; } -EXPORT_SYMBOL_GPL(backport_nla_validate); -int backport_nla_policy_len(const struct nla_policy *p, int n) +/** + * __nla_validate - Validate a stream of attributes + * @head: head of attribute stream + * @len: length of attribute stream + * @maxtype: maximum attribute type to be expected + * @policy: validation policy + * @validate: validation strictness + * @extack: extended ACK report struct + * + * Validates all attributes in the specified attribute stream against the + * specified policy. Validation depends on the validate flags passed, see + * &enum netlink_validation for more details on that. + * See documenation of struct nla_policy for more details. + * + * Returns 0 on success or a negative error code. + */ +int __nla_validate(const struct nlattr *head, int len, int maxtype, + const struct nla_policy *policy, unsigned int validate, + struct netlink_ext_ack *extack) +{ + return __nla_validate_parse(head, len, maxtype, policy, validate, + extack, NULL); +} +EXPORT_SYMBOL(__nla_validate); + +/** + * nla_policy_len - Determin the max. length of a policy + * @policy: policy to use + * @n: number of policies + * + * Determines the max. length of the policy. It is currently used + * to allocated Netlink buffers roughly the size of the actual + * message. + * + * Returns 0 on success or a negative error code. + */ +int +nla_policy_len(const struct nla_policy *p, int n) { int i, len = 0; @@ -342,38 +452,30 @@ int backport_nla_policy_len(const struct nla_policy *p, int n) return len; } -EXPORT_SYMBOL_GPL(backport_nla_policy_len); - -int backport_nla_parse(struct nlattr **tb, int maxtype, - const struct nlattr *head, - int len, const struct nla_policy *policy, - struct netlink_ext_ack *extack) +EXPORT_SYMBOL(nla_policy_len); + +/** + * __nla_parse - Parse a stream of attributes into a tb buffer + * @tb: destination array with maxtype+1 elements + * @maxtype: maximum attribute type to be expected + * @head: head of attribute stream + * @len: length of attribute stream + * @policy: validation policy + * @validate: validation strictness + * @extack: extended ACK pointer + * + * Parses a stream of attributes and stores a pointer to each attribute in + * the tb array accessible via the attribute type. + * Validation is controlled by the @validate parameter. + * + * Returns 0 on success or a negative error code. + */ +int __nla_parse(struct nlattr **tb, int maxtype, + const struct nlattr *head, int len, + const struct nla_policy *policy, unsigned int validate, + struct netlink_ext_ack *extack) { - const struct nlattr *nla; - int rem; - - memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); - - nla_for_each_attr(nla, head, len, rem) { - u16 type = nla_type(nla); - - if (type > 0 && type <= maxtype) { - if (policy) { - int err = validate_nla(nla, maxtype, policy, - extack); - - if (err < 0) - return err; - } - - tb[type] = (struct nlattr *)nla; - } - } - - if (unlikely(rem > 0)) - pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n", - rem, current->comm); - - return 0; + return __nla_validate_parse(head, len, maxtype, policy, validate, + extack, tb); } -EXPORT_SYMBOL(backport_nla_parse); +EXPORT_SYMBOL(__nla_parse); diff --git a/backport/compat/backport-genetlink.c b/backport/compat/backport-genetlink.c index 16971ec3..47078589 100644 --- a/backport/compat/backport-genetlink.c +++ b/backport/compat/backport-genetlink.c @@ -167,8 +167,15 @@ static int backport_pre_doit(__genl_const struct genl_ops *ops, struct netlink_ext_ack *extack = info->extack; #endif - err = nlmsg_validate(info->nlhdr, GENL_HDRLEN + family->hdrsize, - family->maxattr, ops->policy, extack); + if (ops->validate & GENL_DONT_VALIDATE_STRICT) + err = nlmsg_validate_deprecated(info->nlhdr, + GENL_HDRLEN + family->hdrsize, + family->maxattr, family->policy, + extack); + else + err = nlmsg_validate(info->nlhdr, GENL_HDRLEN + family->hdrsize, + family->maxattr, family->policy, extack); + if (!err && family->pre_doit) err = family->pre_doit(ops, skb, info); @@ -230,11 +237,15 @@ int backport_genl_register_family(struct genl_family *family) * memory layout isn't compatible with the old version */ for (i = 0; i < family->n_ops; i++) { - ops[i].policy = NULL; #if LINUX_VERSION_IS_LESS(4,12,0) if (ops[i].doit) ops[i].doit = extack_doit; #endif +/* + * TODO: add dumpit redirect (like extack_doit) that will + * make this code honor !GENL_DONT_VALIDATE_DUMP and + * actually validate in this case ... + */ } /* keep doit/dumpit NULL - that's invalid */ ops[family->n_ops].done = (void *)family; @@ -248,12 +259,13 @@ int backport_genl_register_family(struct genl_family *family) #if LINUX_VERSION_IS_GEQ(3,10,0) COPY(parallel_ops); #endif - family->family.pre_doit = backport_pre_doit; - family->family.post_doit = backport_post_doit; + /* The casts are OK - we checked everything is the same offset in genl_ops */ + family->family.pre_doit = (void *)backport_pre_doit; + family->family.post_doit = (void *)backport_post_doit; /* attrbuf is output only */ - family->copy_ops = ops; + family->copy_ops = (void *)ops; #if LINUX_VERSION_IS_GEQ(3,13,0) - family->family.ops = ops; + family->family.ops = (void *)ops; COPY(mcgrps); COPY(n_ops); COPY(n_mcgrps); -- 2.20.1 -- To unsubscribe from this list: send the line "unsubscribe backports" in