From 7d35812c3214afa5b37a675113555259cfd67b98 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 1 Apr 2016 14:17:23 +0200 Subject: netfilter: x_tables: add and use xt_check_entry_offsets Currently arp/ip and ip6tables each implement a short helper to check that the target offset is large enough to hold one xt_entry_target struct and that t->u.target_size fits within the current rule. Unfortunately these checks are not sufficient. To avoid adding new tests to all of ip/ip6/arptables move the current checks into a helper, then extend this helper in followup patches. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 80a305b85323..0de0862897a4 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -242,6 +242,10 @@ void xt_unregister_match(struct xt_match *target); int xt_register_matches(struct xt_match *match, unsigned int n); void xt_unregister_matches(struct xt_match *match, unsigned int n); +int xt_check_entry_offsets(const void *base, + unsigned int target_offset, + unsigned int next_offset); + int xt_check_match(struct xt_mtchk_param *, unsigned int size, u_int8_t proto, bool inv_proto); int xt_check_target(struct xt_tgchk_param *, unsigned int size, u_int8_t proto, -- cgit v1.2.3-71-gd317 From fc1221b3a163d1386d1052184202d5dc50d302d1 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 1 Apr 2016 14:17:26 +0200 Subject: netfilter: x_tables: add compat version of xt_check_entry_offsets 32bit rulesets have different layout and alignment requirements, so once more integrity checks get added to xt_check_entry_offsets it will reject well-formed 32bit rulesets. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 3 +++ net/ipv4/netfilter/arp_tables.c | 3 ++- net/ipv4/netfilter/ip_tables.c | 3 ++- net/ipv6/netfilter/ip6_tables.c | 3 ++- net/netfilter/x_tables.c | 22 ++++++++++++++++++++++ 5 files changed, 31 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 0de0862897a4..08de48bbe92e 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -494,6 +494,9 @@ void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr, unsigned int *size); int xt_compat_target_to_user(const struct xt_entry_target *t, void __user **dstptr, unsigned int *size); +int xt_compat_check_entry_offsets(const void *base, + unsigned int target_offset, + unsigned int next_offset); #endif /* CONFIG_COMPAT */ #endif /* _X_TABLES_H */ diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 24ad92a60b7a..ab8952a49bfa 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -1254,7 +1254,8 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e, if (!arp_checkentry(&e->arp)) return -EINVAL; - ret = xt_check_entry_offsets(e, e->target_offset, e->next_offset); + ret = xt_compat_check_entry_offsets(e, e->target_offset, + e->next_offset); if (ret) return ret; diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index cdf18502a047..7d24c872723f 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1513,7 +1513,8 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e, if (!ip_checkentry(&e->ip)) return -EINVAL; - ret = xt_check_entry_offsets(e, e->target_offset, e->next_offset); + ret = xt_compat_check_entry_offsets(e, + e->target_offset, e->next_offset); if (ret) return ret; diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index e3783116ed48..73eee7b5fd60 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1525,7 +1525,8 @@ check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e, if (!ip6_checkentry(&e->ipv6)) return -EINVAL; - ret = xt_check_entry_offsets(e, e->target_offset, e->next_offset); + ret = xt_compat_check_entry_offsets(e, + e->target_offset, e->next_offset); if (ret) return ret; diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index ec1b7183fff9..fa206ceb269f 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -539,6 +539,27 @@ int xt_compat_match_to_user(const struct xt_entry_match *m, return 0; } EXPORT_SYMBOL_GPL(xt_compat_match_to_user); + +int xt_compat_check_entry_offsets(const void *base, + unsigned int target_offset, + unsigned int next_offset) +{ + const struct compat_xt_entry_target *t; + const char *e = base; + + if (target_offset + sizeof(*t) > next_offset) + return -EINVAL; + + t = (void *)(e + target_offset); + if (t->u.target_size < sizeof(*t)) + return -EINVAL; + + if (target_offset + t->u.target_size > next_offset) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL(xt_compat_check_entry_offsets); #endif /* CONFIG_COMPAT */ /** @@ -549,6 +570,7 @@ EXPORT_SYMBOL_GPL(xt_compat_match_to_user); * @next_offset: the arp/ip/ip6_t->next_offset * * validates that target_offset and next_offset are sane. + * Also see xt_compat_check_entry_offsets for CONFIG_COMPAT version. * * The arp/ip/ip6t_entry structure @base must have passed following tests: * - it must point to a valid memory location -- cgit v1.2.3-71-gd317 From ce683e5f9d045e5d67d1312a42b359cb2ab2a13c Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 1 Apr 2016 14:17:28 +0200 Subject: netfilter: x_tables: check for bogus target offset We're currently asserting that targetoff + targetsize <= nextoff. Extend it to also check that targetoff is >= sizeof(xt_entry). Since this is generic code, add an argument pointing to the start of the match/target, we can then derive the base structure size from the delta. We also need the e->elems pointer in a followup change to validate matches. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 4 ++-- net/ipv4/netfilter/arp_tables.c | 5 +++-- net/ipv4/netfilter/ip_tables.c | 5 +++-- net/ipv6/netfilter/ip6_tables.c | 5 +++-- net/netfilter/x_tables.c | 17 +++++++++++++++-- 5 files changed, 26 insertions(+), 10 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 08de48bbe92e..30cfb1e943fb 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -242,7 +242,7 @@ void xt_unregister_match(struct xt_match *target); int xt_register_matches(struct xt_match *match, unsigned int n); void xt_unregister_matches(struct xt_match *match, unsigned int n); -int xt_check_entry_offsets(const void *base, +int xt_check_entry_offsets(const void *base, const char *elems, unsigned int target_offset, unsigned int next_offset); @@ -494,7 +494,7 @@ void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr, unsigned int *size); int xt_compat_target_to_user(const struct xt_entry_target *t, void __user **dstptr, unsigned int *size); -int xt_compat_check_entry_offsets(const void *base, +int xt_compat_check_entry_offsets(const void *base, const char *elems, unsigned int target_offset, unsigned int next_offset); diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index ab8952a49bfa..95ed4e454c60 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -592,7 +592,8 @@ static inline int check_entry_size_and_hooks(struct arpt_entry *e, if (!arp_checkentry(&e->arp)) return -EINVAL; - err = xt_check_entry_offsets(e, e->target_offset, e->next_offset); + err = xt_check_entry_offsets(e, e->elems, e->target_offset, + e->next_offset); if (err) return err; @@ -1254,7 +1255,7 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e, if (!arp_checkentry(&e->arp)) return -EINVAL; - ret = xt_compat_check_entry_offsets(e, e->target_offset, + ret = xt_compat_check_entry_offsets(e, e->elems, e->target_offset, e->next_offset); if (ret) return ret; diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 7d24c872723f..baab033d74e0 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -754,7 +754,8 @@ check_entry_size_and_hooks(struct ipt_entry *e, if (!ip_checkentry(&e->ip)) return -EINVAL; - err = xt_check_entry_offsets(e, e->target_offset, e->next_offset); + err = xt_check_entry_offsets(e, e->elems, e->target_offset, + e->next_offset); if (err) return err; @@ -1513,7 +1514,7 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e, if (!ip_checkentry(&e->ip)) return -EINVAL; - ret = xt_compat_check_entry_offsets(e, + ret = xt_compat_check_entry_offsets(e, e->elems, e->target_offset, e->next_offset); if (ret) return ret; diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index 73eee7b5fd60..6957627c7931 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -766,7 +766,8 @@ check_entry_size_and_hooks(struct ip6t_entry *e, if (!ip6_checkentry(&e->ipv6)) return -EINVAL; - err = xt_check_entry_offsets(e, e->target_offset, e->next_offset); + err = xt_check_entry_offsets(e, e->elems, e->target_offset, + e->next_offset); if (err) return err; @@ -1525,7 +1526,7 @@ check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e, if (!ip6_checkentry(&e->ipv6)) return -EINVAL; - ret = xt_compat_check_entry_offsets(e, + ret = xt_compat_check_entry_offsets(e, e->elems, e->target_offset, e->next_offset); if (ret) return ret; diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 1cb7a271c024..e2a6f2a9051b 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -546,14 +546,17 @@ struct compat_xt_standard_target { compat_uint_t verdict; }; -/* see xt_check_entry_offsets */ -int xt_compat_check_entry_offsets(const void *base, +int xt_compat_check_entry_offsets(const void *base, const char *elems, unsigned int target_offset, unsigned int next_offset) { + long size_of_base_struct = elems - (const char *)base; const struct compat_xt_entry_target *t; const char *e = base; + if (target_offset < size_of_base_struct) + return -EINVAL; + if (target_offset + sizeof(*t) > next_offset) return -EINVAL; @@ -577,12 +580,16 @@ EXPORT_SYMBOL(xt_compat_check_entry_offsets); * xt_check_entry_offsets - validate arp/ip/ip6t_entry * * @base: pointer to arp/ip/ip6t_entry + * @elems: pointer to first xt_entry_match, i.e. ip(6)t_entry->elems * @target_offset: the arp/ip/ip6_t->target_offset * @next_offset: the arp/ip/ip6_t->next_offset * * validates that target_offset and next_offset are sane. * Also see xt_compat_check_entry_offsets for CONFIG_COMPAT version. * + * This function does not validate the targets or matches themselves, it + * only tests that all the offsets and sizes are correct. + * * The arp/ip/ip6t_entry structure @base must have passed following tests: * - it must point to a valid memory location * - base to base + next_offset must be accessible, i.e. not exceed allocated @@ -591,12 +598,18 @@ EXPORT_SYMBOL(xt_compat_check_entry_offsets); * Return: 0 on success, negative errno on failure. */ int xt_check_entry_offsets(const void *base, + const char *elems, unsigned int target_offset, unsigned int next_offset) { + long size_of_base_struct = elems - (const char *)base; const struct xt_entry_target *t; const char *e = base; + /* target start is within the ip/ip6/arpt_entry struct */ + if (target_offset < size_of_base_struct) + return -EINVAL; + if (target_offset + sizeof(*t) > next_offset) return -EINVAL; -- cgit v1.2.3-71-gd317 From 0188346f21e6546498c2a0f84888797ad4063fc5 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 1 Apr 2016 14:17:33 +0200 Subject: netfilter: x_tables: xt_compat_match_from_user doesn't need a retval Always returned 0. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 2 +- net/ipv4/netfilter/arp_tables.c | 17 +++++------------ net/ipv4/netfilter/ip_tables.c | 26 +++++++++----------------- net/ipv6/netfilter/ip6_tables.c | 27 +++++++++------------------ net/netfilter/x_tables.c | 5 ++--- 5 files changed, 26 insertions(+), 51 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 30cfb1e943fb..e2da9b90f1b8 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -484,7 +484,7 @@ void xt_compat_init_offsets(u_int8_t af, unsigned int number); int xt_compat_calc_jump(u_int8_t af, unsigned int offset); int xt_compat_match_offset(const struct xt_match *match); -int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr, +void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr, unsigned int *size); int xt_compat_match_to_user(const struct xt_entry_match *m, void __user **dstptr, unsigned int *size); diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 1d1386dc159b..be514c676fad 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -1310,7 +1310,7 @@ out: return ret; } -static int +static void compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr, unsigned int *size, struct xt_table_info *newinfo, unsigned char *base) @@ -1319,9 +1319,8 @@ compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr, struct xt_target *target; struct arpt_entry *de; unsigned int origsize; - int ret, h; + int h; - ret = 0; origsize = *size; de = (struct arpt_entry *)*dstptr; memcpy(de, e, sizeof(struct arpt_entry)); @@ -1342,7 +1341,6 @@ compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr, if ((unsigned char *)de - base < newinfo->underflow[h]) newinfo->underflow[h] -= origsize - *size; } - return ret; } static int translate_compat_table(struct xt_table_info **pinfo, @@ -1421,16 +1419,11 @@ static int translate_compat_table(struct xt_table_info **pinfo, entry1 = newinfo->entries; pos = entry1; size = compatr->size; - xt_entry_foreach(iter0, entry0, compatr->size) { - ret = compat_copy_entry_from_user(iter0, &pos, &size, - newinfo, entry1); - if (ret != 0) - break; - } + xt_entry_foreach(iter0, entry0, compatr->size) + compat_copy_entry_from_user(iter0, &pos, &size, + newinfo, entry1); xt_compat_flush_offsets(NFPROTO_ARP); xt_compat_unlock(NFPROTO_ARP); - if (ret) - goto free_newinfo; ret = -ELOOP; if (!mark_source_chains(newinfo, compatr->valid_hooks, entry1)) diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index d70418604503..5c20eef980c1 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1568,7 +1568,7 @@ release_matches: return ret; } -static int +static void compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr, unsigned int *size, struct xt_table_info *newinfo, unsigned char *base) @@ -1577,10 +1577,9 @@ compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr, struct xt_target *target; struct ipt_entry *de; unsigned int origsize; - int ret, h; + int h; struct xt_entry_match *ematch; - ret = 0; origsize = *size; de = (struct ipt_entry *)*dstptr; memcpy(de, e, sizeof(struct ipt_entry)); @@ -1589,11 +1588,9 @@ compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr, *dstptr += sizeof(struct ipt_entry); *size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); - xt_ematch_foreach(ematch, e) { - ret = xt_compat_match_from_user(ematch, dstptr, size); - if (ret != 0) - return ret; - } + xt_ematch_foreach(ematch, e) + xt_compat_match_from_user(ematch, dstptr, size); + de->target_offset = e->target_offset - (origsize - *size); t = compat_ipt_get_target(e); target = t->u.kernel.target; @@ -1606,7 +1603,6 @@ compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr, if ((unsigned char *)de - base < newinfo->underflow[h]) newinfo->underflow[h] -= origsize - *size; } - return ret; } static int @@ -1729,16 +1725,12 @@ translate_compat_table(struct net *net, entry1 = newinfo->entries; pos = entry1; size = compatr->size; - xt_entry_foreach(iter0, entry0, compatr->size) { - ret = compat_copy_entry_from_user(iter0, &pos, &size, - newinfo, entry1); - if (ret != 0) - break; - } + xt_entry_foreach(iter0, entry0, compatr->size) + compat_copy_entry_from_user(iter0, &pos, &size, + newinfo, entry1); + xt_compat_flush_offsets(AF_INET); xt_compat_unlock(AF_INET); - if (ret) - goto free_newinfo; ret = -ELOOP; if (!mark_source_chains(newinfo, compatr->valid_hooks, entry1)) diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index 8d082c557771..620d54c1c119 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1580,7 +1580,7 @@ release_matches: return ret; } -static int +static void compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr, unsigned int *size, struct xt_table_info *newinfo, unsigned char *base) @@ -1588,10 +1588,9 @@ compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr, struct xt_entry_target *t; struct ip6t_entry *de; unsigned int origsize; - int ret, h; + int h; struct xt_entry_match *ematch; - ret = 0; origsize = *size; de = (struct ip6t_entry *)*dstptr; memcpy(de, e, sizeof(struct ip6t_entry)); @@ -1600,11 +1599,9 @@ compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr, *dstptr += sizeof(struct ip6t_entry); *size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); - xt_ematch_foreach(ematch, e) { - ret = xt_compat_match_from_user(ematch, dstptr, size); - if (ret != 0) - return ret; - } + xt_ematch_foreach(ematch, e) + xt_compat_match_from_user(ematch, dstptr, size); + de->target_offset = e->target_offset - (origsize - *size); t = compat_ip6t_get_target(e); xt_compat_target_from_user(t, dstptr, size); @@ -1616,7 +1613,6 @@ compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr, if ((unsigned char *)de - base < newinfo->underflow[h]) newinfo->underflow[h] -= origsize - *size; } - return ret; } static int compat_check_entry(struct ip6t_entry *e, struct net *net, @@ -1737,17 +1733,12 @@ translate_compat_table(struct net *net, } entry1 = newinfo->entries; pos = entry1; - size = compatr->size; - xt_entry_foreach(iter0, entry0, compatr->size) { - ret = compat_copy_entry_from_user(iter0, &pos, &size, - newinfo, entry1); - if (ret != 0) - break; - } + xt_entry_foreach(iter0, entry0, compatr->size) + compat_copy_entry_from_user(iter0, &pos, &size, + newinfo, entry1); + xt_compat_flush_offsets(AF_INET6); xt_compat_unlock(AF_INET6); - if (ret) - goto free_newinfo; ret = -ELOOP; if (!mark_source_chains(newinfo, compatr->valid_hooks, entry1)) diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index f9aa9715c32e..7e7173b68344 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -526,8 +526,8 @@ int xt_compat_match_offset(const struct xt_match *match) } EXPORT_SYMBOL_GPL(xt_compat_match_offset); -int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr, - unsigned int *size) +void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr, + unsigned int *size) { const struct xt_match *match = m->u.kernel.match; struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m; @@ -549,7 +549,6 @@ int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr, *size += off; *dstptr += msize; - return 0; } EXPORT_SYMBOL_GPL(xt_compat_match_from_user); -- cgit v1.2.3-71-gd317 From d7591f0c41ce3e67600a982bab6989ef0f07b3ce Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 1 Apr 2016 15:37:59 +0200 Subject: netfilter: x_tables: introduce and use xt_copy_counters_from_user The three variants use same copy&pasted code, condense this into a helper and use that. Make sure info.name is 0-terminated. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 3 ++ net/ipv4/netfilter/arp_tables.c | 48 +++---------------------- net/ipv4/netfilter/ip_tables.c | 48 +++---------------------- net/ipv6/netfilter/ip6_tables.c | 49 +++---------------------- net/netfilter/x_tables.c | 74 ++++++++++++++++++++++++++++++++++++++ 5 files changed, 92 insertions(+), 130 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index e2da9b90f1b8..4dd9306c9d56 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -251,6 +251,9 @@ int xt_check_match(struct xt_mtchk_param *, unsigned int size, u_int8_t proto, int xt_check_target(struct xt_tgchk_param *, unsigned int size, u_int8_t proto, bool inv_proto); +void *xt_copy_counters_from_user(const void __user *user, unsigned int len, + struct xt_counters_info *info, bool compat); + struct xt_table *xt_register_table(struct net *net, const struct xt_table *table, struct xt_table_info *bootstrap, diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 8cefb7a2606b..60f5161abcb4 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -1123,55 +1123,17 @@ static int do_add_counters(struct net *net, const void __user *user, unsigned int i; struct xt_counters_info tmp; struct xt_counters *paddc; - unsigned int num_counters; - const char *name; - int size; - void *ptmp; struct xt_table *t; const struct xt_table_info *private; int ret = 0; struct arpt_entry *iter; unsigned int addend; -#ifdef CONFIG_COMPAT - struct compat_xt_counters_info compat_tmp; - - if (compat) { - ptmp = &compat_tmp; - size = sizeof(struct compat_xt_counters_info); - } else -#endif - { - ptmp = &tmp; - size = sizeof(struct xt_counters_info); - } - if (copy_from_user(ptmp, user, size) != 0) - return -EFAULT; - -#ifdef CONFIG_COMPAT - if (compat) { - num_counters = compat_tmp.num_counters; - name = compat_tmp.name; - } else -#endif - { - num_counters = tmp.num_counters; - name = tmp.name; - } - - if (len != size + num_counters * sizeof(struct xt_counters)) - return -EINVAL; - - paddc = vmalloc(len - size); - if (!paddc) - return -ENOMEM; - - if (copy_from_user(paddc, user + size, len - size) != 0) { - ret = -EFAULT; - goto free; - } + paddc = xt_copy_counters_from_user(user, len, &tmp, compat); + if (IS_ERR(paddc)) + return PTR_ERR(paddc); - t = xt_find_table_lock(net, NFPROTO_ARP, name); + t = xt_find_table_lock(net, NFPROTO_ARP, tmp.name); if (IS_ERR_OR_NULL(t)) { ret = t ? PTR_ERR(t) : -ENOENT; goto free; @@ -1179,7 +1141,7 @@ static int do_add_counters(struct net *net, const void __user *user, local_bh_disable(); private = t->private; - if (private->number != num_counters) { + if (private->number != tmp.num_counters) { ret = -EINVAL; goto unlock_up_free; } diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 9340ce0a7549..735d1ee8c1ab 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1307,55 +1307,17 @@ do_add_counters(struct net *net, const void __user *user, unsigned int i; struct xt_counters_info tmp; struct xt_counters *paddc; - unsigned int num_counters; - const char *name; - int size; - void *ptmp; struct xt_table *t; const struct xt_table_info *private; int ret = 0; struct ipt_entry *iter; unsigned int addend; -#ifdef CONFIG_COMPAT - struct compat_xt_counters_info compat_tmp; - - if (compat) { - ptmp = &compat_tmp; - size = sizeof(struct compat_xt_counters_info); - } else -#endif - { - ptmp = &tmp; - size = sizeof(struct xt_counters_info); - } - if (copy_from_user(ptmp, user, size) != 0) - return -EFAULT; - -#ifdef CONFIG_COMPAT - if (compat) { - num_counters = compat_tmp.num_counters; - name = compat_tmp.name; - } else -#endif - { - num_counters = tmp.num_counters; - name = tmp.name; - } - - if (len != size + num_counters * sizeof(struct xt_counters)) - return -EINVAL; - - paddc = vmalloc(len - size); - if (!paddc) - return -ENOMEM; - - if (copy_from_user(paddc, user + size, len - size) != 0) { - ret = -EFAULT; - goto free; - } + paddc = xt_copy_counters_from_user(user, len, &tmp, compat); + if (IS_ERR(paddc)) + return PTR_ERR(paddc); - t = xt_find_table_lock(net, AF_INET, name); + t = xt_find_table_lock(net, AF_INET, tmp.name); if (IS_ERR_OR_NULL(t)) { ret = t ? PTR_ERR(t) : -ENOENT; goto free; @@ -1363,7 +1325,7 @@ do_add_counters(struct net *net, const void __user *user, local_bh_disable(); private = t->private; - if (private->number != num_counters) { + if (private->number != tmp.num_counters) { ret = -EINVAL; goto unlock_up_free; } diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index aa010856a255..73e606c719ef 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1319,55 +1319,16 @@ do_add_counters(struct net *net, const void __user *user, unsigned int len, unsigned int i; struct xt_counters_info tmp; struct xt_counters *paddc; - unsigned int num_counters; - char *name; - int size; - void *ptmp; struct xt_table *t; const struct xt_table_info *private; int ret = 0; struct ip6t_entry *iter; unsigned int addend; -#ifdef CONFIG_COMPAT - struct compat_xt_counters_info compat_tmp; - - if (compat) { - ptmp = &compat_tmp; - size = sizeof(struct compat_xt_counters_info); - } else -#endif - { - ptmp = &tmp; - size = sizeof(struct xt_counters_info); - } - - if (copy_from_user(ptmp, user, size) != 0) - return -EFAULT; - -#ifdef CONFIG_COMPAT - if (compat) { - num_counters = compat_tmp.num_counters; - name = compat_tmp.name; - } else -#endif - { - num_counters = tmp.num_counters; - name = tmp.name; - } - - if (len != size + num_counters * sizeof(struct xt_counters)) - return -EINVAL; - - paddc = vmalloc(len - size); - if (!paddc) - return -ENOMEM; - - if (copy_from_user(paddc, user + size, len - size) != 0) { - ret = -EFAULT; - goto free; - } - t = xt_find_table_lock(net, AF_INET6, name); + paddc = xt_copy_counters_from_user(user, len, &tmp, compat); + if (IS_ERR(paddc)) + return PTR_ERR(paddc); + t = xt_find_table_lock(net, AF_INET6, tmp.name); if (IS_ERR_OR_NULL(t)) { ret = t ? PTR_ERR(t) : -ENOENT; goto free; @@ -1375,7 +1336,7 @@ do_add_counters(struct net *net, const void __user *user, unsigned int len, local_bh_disable(); private = t->private; - if (private->number != num_counters) { + if (private->number != tmp.num_counters) { ret = -EINVAL; goto unlock_up_free; } diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 9ec23ffa43b4..c69c892231d7 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -752,6 +752,80 @@ int xt_check_target(struct xt_tgchk_param *par, } EXPORT_SYMBOL_GPL(xt_check_target); +/** + * xt_copy_counters_from_user - copy counters and metadata from userspace + * + * @user: src pointer to userspace memory + * @len: alleged size of userspace memory + * @info: where to store the xt_counters_info metadata + * @compat: true if we setsockopt call is done by 32bit task on 64bit kernel + * + * Copies counter meta data from @user and stores it in @info. + * + * vmallocs memory to hold the counters, then copies the counter data + * from @user to the new memory and returns a pointer to it. + * + * If @compat is true, @info gets converted automatically to the 64bit + * representation. + * + * The metadata associated with the counters is stored in @info. + * + * Return: returns pointer that caller has to test via IS_ERR(). + * If IS_ERR is false, caller has to vfree the pointer. + */ +void *xt_copy_counters_from_user(const void __user *user, unsigned int len, + struct xt_counters_info *info, bool compat) +{ + void *mem; + u64 size; + +#ifdef CONFIG_COMPAT + if (compat) { + /* structures only differ in size due to alignment */ + struct compat_xt_counters_info compat_tmp; + + if (len <= sizeof(compat_tmp)) + return ERR_PTR(-EINVAL); + + len -= sizeof(compat_tmp); + if (copy_from_user(&compat_tmp, user, sizeof(compat_tmp)) != 0) + return ERR_PTR(-EFAULT); + + strlcpy(info->name, compat_tmp.name, sizeof(info->name)); + info->num_counters = compat_tmp.num_counters; + user += sizeof(compat_tmp); + } else +#endif + { + if (len <= sizeof(*info)) + return ERR_PTR(-EINVAL); + + len -= sizeof(*info); + if (copy_from_user(info, user, sizeof(*info)) != 0) + return ERR_PTR(-EFAULT); + + info->name[sizeof(info->name) - 1] = '\0'; + user += sizeof(*info); + } + + size = sizeof(struct xt_counters); + size *= info->num_counters; + + if (size != (u64)len) + return ERR_PTR(-EINVAL); + + mem = vmalloc(len); + if (!mem) + return ERR_PTR(-ENOMEM); + + if (copy_from_user(mem, user, len) == 0) + return mem; + + vfree(mem); + return ERR_PTR(-EFAULT); +} +EXPORT_SYMBOL_GPL(xt_copy_counters_from_user); + #ifdef CONFIG_COMPAT int xt_compat_target_offset(const struct xt_target *target) { -- cgit v1.2.3-71-gd317