Date: Tue, 9 May 2023 15:00:11 GMT From: "Alexander V. Chernikov" <melifaro@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: ba9c815d3076 - main - netlink: use consistent variable lifetime in the default snl(3) parsers. Message-ID: <202305091500.349F0BY5070665@gitrepo.freebsd.org>
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The branch main has been updated by melifaro: URL: https://cgit.FreeBSD.org/src/commit/?id=ba9c815d3076f5a13ab6f9ec3f6d534e7774e83b commit ba9c815d3076f5a13ab6f9ec3f6d534e7774e83b Author: Alexander V. Chernikov <melifaro@FreeBSD.org> AuthorDate: 2023-05-09 14:45:57 +0000 Commit: Alexander V. Chernikov <melifaro@FreeBSD.org> CommitDate: 2023-05-09 14:45:57 +0000 netlink: use consistent variable lifetime in the default snl(3) parsers. Currently, parsers use original strings/nla pointers instead of duplicating them. These pointers refer to the temporary packet buffer, which can be silently rewritten when the next message is read. Instead, duplicate all string/nla attributes using snl_allocz(3) to give control over variable lifetime to the user. MFC after: 2 weeks --- sys/netlink/netlink_snl.h | 45 +++++++++++++++++++++++++++++++++ sys/netlink/netlink_snl_route_parsers.h | 16 ++++++------ 2 files changed, 53 insertions(+), 8 deletions(-) diff --git a/sys/netlink/netlink_snl.h b/sys/netlink/netlink_snl.h index 822cec9b4dc4..83892c156273 100644 --- a/sys/netlink/netlink_snl.h +++ b/sys/netlink/netlink_snl.h @@ -606,6 +606,23 @@ snl_attr_copy_string(struct snl_state *ss, struct nlattr *nla, return (false); } +static inline bool +snl_attr_dup_string(struct snl_state *ss __unused, struct nlattr *nla, + const void *arg __unused, void *target) +{ + size_t maxlen = NLA_DATA_LEN(nla); + + if (strnlen((char *)NLA_DATA(nla), maxlen) < maxlen) { + char *buf = snl_allocz(ss, maxlen); + if (buf == NULL) + return (false); + memcpy(buf, NLA_DATA(nla), maxlen); + *((char **)target) = buf; + return (true); + } + return (false); +} + static inline bool snl_attr_get_nested(struct snl_state *ss, struct nlattr *nla, const void *arg, void *target) { @@ -623,6 +640,20 @@ snl_attr_get_nla(struct snl_state *ss __unused, struct nlattr *nla, return (true); } +static inline bool +snl_attr_dup_nla(struct snl_state *ss __unused, struct nlattr *nla, + const void *arg __unused, void *target) +{ + void *ptr = snl_allocz(ss, nla->nla_len); + + if (ptr != NULL) { + memcpy(ptr, nla, nla->nla_len); + *((void **)target) = ptr; + return (true); + } + return (false); +} + static inline bool snl_attr_copy_struct(struct snl_state *ss, struct nlattr *nla, const void *arg __unused, void *target) @@ -637,6 +668,20 @@ snl_attr_copy_struct(struct snl_state *ss, struct nlattr *nla, return (false); } +static inline bool +snl_attr_dup_struct(struct snl_state *ss, struct nlattr *nla, + const void *arg __unused, void *target) +{ + void *ptr = snl_allocz(ss, NLA_DATA_LEN(nla)); + + if (ptr != NULL) { + memcpy(ptr, NLA_DATA(nla), NLA_DATA_LEN(nla)); + *((void **)target) = ptr; + return (true); + } + return (false); +} + static inline void snl_field_get_uint8(struct snl_state *ss __unused, void *src, void *target) { diff --git a/sys/netlink/netlink_snl_route_parsers.h b/sys/netlink/netlink_snl_route_parsers.h index 94dc20861c3f..1afbe3feeeb9 100644 --- a/sys/netlink/netlink_snl_route_parsers.h +++ b/sys/netlink/netlink_snl_route_parsers.h @@ -177,13 +177,13 @@ struct snl_parsed_link { #define _IN(_field) offsetof(struct ifinfomsg, _field) #define _OUT(_field) offsetof(struct snl_parsed_link, _field) static const struct snl_attr_parser _nla_p_link[] = { - { .type = IFLA_ADDRESS, .off = _OUT(ifla_address), .cb = snl_attr_get_nla }, - { .type = IFLA_BROADCAST, .off = _OUT(ifla_broadcast), .cb = snl_attr_get_nla }, - { .type = IFLA_IFNAME, .off = _OUT(ifla_ifname), .cb = snl_attr_get_string }, + { .type = IFLA_ADDRESS, .off = _OUT(ifla_address), .cb = snl_attr_dup_nla }, + { .type = IFLA_BROADCAST, .off = _OUT(ifla_broadcast), .cb = snl_attr_dup_nla }, + { .type = IFLA_IFNAME, .off = _OUT(ifla_ifname), .cb = snl_attr_dup_string }, { .type = IFLA_MTU, .off = _OUT(ifla_mtu), .cb = snl_attr_get_uint32 }, { .type = IFLA_OPERSTATE, .off = _OUT(ifla_operstate), .cb = snl_attr_get_uint8 }, - { .type = IFLA_IFALIAS, .off = _OUT(ifla_ifalias), .cb = snl_attr_get_string }, - { .type = IFLA_STATS64, .off = _OUT(ifla_stats64), .cb = snl_attr_copy_struct }, + { .type = IFLA_IFALIAS, .off = _OUT(ifla_ifalias), .cb = snl_attr_dup_string }, + { .type = IFLA_STATS64, .off = _OUT(ifla_stats64), .cb = snl_attr_dup_struct }, { .type = IFLA_PROMISCUITY, .off = _OUT(ifla_promiscuity), .cb = snl_attr_get_uint32 }, { .type = IFLA_CARRIER, .off = _OUT(ifla_carrier), .cb = snl_attr_get_uint8 }, }; @@ -208,7 +208,7 @@ struct snl_parsed_link_simple { #define _IN(_field) offsetof(struct ifinfomsg, _field) #define _OUT(_field) offsetof(struct snl_parsed_link_simple, _field) static struct snl_attr_parser _nla_p_link_s[] = { - { .type = IFLA_IFNAME, .off = _OUT(ifla_ifname), .cb = snl_attr_get_string }, + { .type = IFLA_IFNAME, .off = _OUT(ifla_ifname), .cb = snl_attr_dup_string }, { .type = IFLA_MTU, .off = _OUT(ifla_mtu), .cb = snl_attr_get_uint32 }, }; static struct snl_field_parser _fp_p_link_s[] = { @@ -240,7 +240,7 @@ SNL_DECLARE_ATTR_PARSER(_neigh_fbsd_parser, _nla_p_neigh_fbsd); static struct snl_attr_parser _nla_p_neigh_s[] = { { .type = NDA_DST, .off = _OUT(nda_dst), .cb = snl_attr_get_ip }, - { .type = NDA_LLADDR , .off = _OUT(nda_lladdr), .cb = snl_attr_get_nla }, + { .type = NDA_LLADDR , .off = _OUT(nda_lladdr), .cb = snl_attr_dup_nla }, { .type = NDA_PROBES, .off = _OUT(nda_probes), .cb = snl_attr_get_uint32 }, { .type = NDA_IFINDEX, .off = _OUT(nda_ifindex), .cb = snl_attr_get_uint32 }, { .type = NDA_FREEBSD, .arg = &_neigh_fbsd_parser, .cb = snl_attr_get_nested }, @@ -270,7 +270,7 @@ struct snl_parsed_addr { static struct snl_attr_parser _nla_p_addr_s[] = { { .type = IFA_ADDRESS, .off = _OUT(ifa_address), .cb = snl_attr_get_ip }, { .type = IFA_LOCAL, .off = _OUT(ifa_local), .cb = snl_attr_get_ip }, - { .type = IFA_LABEL, .off = _OUT(ifa_label), .cb = snl_attr_get_string }, + { .type = IFA_LABEL, .off = _OUT(ifa_label), .cb = snl_attr_dup_string }, { .type = IFA_BROADCAST, .off = _OUT(ifa_broadcast), .cb = snl_attr_get_ip }, }; static struct snl_field_parser _fp_p_addr_s[] = {
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