From d91fc59cd77c719f33eda65c194ad8f95a055190 Mon Sep 17 00:00:00 2001 From: Liping Zhang Date: Sun, 7 May 2017 22:01:55 +0800 Subject: netfilter: introduce nf_conntrack_helper_put helper function And convert module_put invocation to nf_conntrack_helper_put, this is prepared for the followup patch, which will add a refcnt for cthelper, so we can reject the deleting request when cthelper is in use. Signed-off-by: Liping Zhang Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_helper.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h index e04fa7691e5d..c1c12411103a 100644 --- a/include/net/netfilter/nf_conntrack_helper.h +++ b/include/net/netfilter/nf_conntrack_helper.h @@ -79,6 +79,8 @@ struct nf_conntrack_helper *__nf_conntrack_helper_find(const char *name, struct nf_conntrack_helper *nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum); +void nf_conntrack_helper_put(struct nf_conntrack_helper *helper); + void nf_ct_helper_init(struct nf_conntrack_helper *helper, u16 l3num, u16 protonum, const char *name, u16 default_port, u16 spec_port, u32 id, -- cgit 1.4.1 From 9338d7b4418e9996a7642867d8f6b482a6040ed6 Mon Sep 17 00:00:00 2001 From: Liping Zhang Date: Sun, 7 May 2017 22:01:56 +0800 Subject: netfilter: nfnl_cthelper: reject del request if helper obj is in use We can still delete the ct helper even if it is in use, this will cause a use-after-free error. In more detail, I mean: # nfct helper add ssdp inet udp # iptables -t raw -A OUTPUT -p udp -j CT --helper ssdp # nfct helper delete ssdp //--> oops, succeed! BUG: unable to handle kernel paging request at 000026ca IP: 0x26ca [...] Call Trace: ? ipv4_helper+0x62/0x80 [nf_conntrack_ipv4] nf_hook_slow+0x21/0xb0 ip_output+0xe9/0x100 ? ip_fragment.constprop.54+0xc0/0xc0 ip_local_out+0x33/0x40 ip_send_skb+0x16/0x80 udp_send_skb+0x84/0x240 udp_sendmsg+0x35d/0xa50 So add reference count to fix this issue, if ct helper is used by others, reject the delete request. Apply this patch: # nfct helper delete ssdp nfct v1.4.3: netlink error: Device or resource busy Signed-off-by: Liping Zhang Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_helper.h | 2 ++ net/netfilter/nf_conntrack_helper.c | 6 ++++++ net/netfilter/nfnetlink_cthelper.c | 17 +++++++++++------ 3 files changed, 19 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h index c1c12411103a..c519bb5b5bb8 100644 --- a/include/net/netfilter/nf_conntrack_helper.h +++ b/include/net/netfilter/nf_conntrack_helper.h @@ -9,6 +9,7 @@ #ifndef _NF_CONNTRACK_HELPER_H #define _NF_CONNTRACK_HELPER_H +#include #include #include #include @@ -26,6 +27,7 @@ struct nf_conntrack_helper { struct hlist_node hnode; /* Internal use. */ char name[NF_CT_HELPER_NAME_LEN]; /* name of the module */ + refcount_t refcnt; struct module *me; /* pointer to self */ const struct nf_conntrack_expect_policy *expect_policy; diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index e17006b6e434..7f6100ca63be 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -174,6 +174,10 @@ nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum) #endif if (h != NULL && !try_module_get(h->me)) h = NULL; + if (h != NULL && !refcount_inc_not_zero(&h->refcnt)) { + module_put(h->me); + h = NULL; + } rcu_read_unlock(); @@ -183,6 +187,7 @@ EXPORT_SYMBOL_GPL(nf_conntrack_helper_try_module_get); void nf_conntrack_helper_put(struct nf_conntrack_helper *helper) { + refcount_dec(&helper->refcnt); module_put(helper->me); } EXPORT_SYMBOL_GPL(nf_conntrack_helper_put); @@ -423,6 +428,7 @@ int nf_conntrack_helper_register(struct nf_conntrack_helper *me) } } } + refcount_set(&me->refcnt, 1); hlist_add_head_rcu(&me->hnode, &nf_ct_helper_hash[h]); nf_ct_helper_count++; out: diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c index 950bf6eadc65..be678a323598 100644 --- a/net/netfilter/nfnetlink_cthelper.c +++ b/net/netfilter/nfnetlink_cthelper.c @@ -686,6 +686,7 @@ static int nfnl_cthelper_del(struct net *net, struct sock *nfnl, tuple_set = true; } + ret = -ENOENT; list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) { cur = &nlcth->helper; j++; @@ -699,16 +700,20 @@ static int nfnl_cthelper_del(struct net *net, struct sock *nfnl, tuple.dst.protonum != cur->tuple.dst.protonum)) continue; - found = true; - nf_conntrack_helper_unregister(cur); - kfree(cur->expect_policy); + if (refcount_dec_if_one(&cur->refcnt)) { + found = true; + nf_conntrack_helper_unregister(cur); + kfree(cur->expect_policy); - list_del(&nlcth->list); - kfree(nlcth); + list_del(&nlcth->list); + kfree(nlcth); + } else { + ret = -EBUSY; + } } /* Make sure we return success if we flush and there is no helpers */ - return (found || j == 0) ? 0 : -ENOENT; + return (found || j == 0) ? 0 : ret; } static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = { -- cgit 1.4.1 From 324318f0248c31be8a08984146e7e4dd7cdd091d Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Tue, 9 May 2017 16:17:37 -0400 Subject: netfilter: xtables: zero padding in data_to_user When looking up an iptables rule, the iptables binary compares the aligned match and target data (XT_ALIGN). In some cases this can exceed the actual data size to include padding bytes. Before commit f77bc5b23fb1 ("iptables: use match, target and data copy_to_user helpers") the malloc()ed bytes were overwritten by the kernel with kzalloced contents, zeroing the padding and making the comparison succeed. After this patch, the kernel copies and clears only data, leaving the padding bytes undefined. Extend the clear operation from data size to aligned data size to include the padding bytes, if any. Padding bytes can be observed in both match and target, and the bug triggered, by issuing a rule with match icmp and target ACCEPT: iptables -t mangle -A INPUT -i lo -p icmp --icmp-type 1 -j ACCEPT iptables -t mangle -D INPUT -i lo -p icmp --icmp-type 1 -j ACCEPT Fixes: f77bc5b23fb1 ("iptables: use match, target and data copy_to_user helpers") Reported-by: Paul Moore Reported-by: Richard Guy Briggs Signed-off-by: Willem de Bruijn Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 2 +- net/bridge/netfilter/ebtables.c | 9 ++++++--- net/netfilter/x_tables.c | 9 ++++++--- 3 files changed, 13 insertions(+), 7 deletions(-) (limited to 'include') diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index be378cf47fcc..b3044c2c62cb 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -294,7 +294,7 @@ int xt_match_to_user(const struct xt_entry_match *m, int xt_target_to_user(const struct xt_entry_target *t, struct xt_entry_target __user *u); int xt_data_to_user(void __user *dst, const void *src, - int usersize, int size); + int usersize, int size, int aligned_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/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 9ec0c9f908fa..9c6e619f452b 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -1373,7 +1373,8 @@ static inline int ebt_obj_to_user(char __user *um, const char *_name, strlcpy(name, _name, sizeof(name)); if (copy_to_user(um, name, EBT_FUNCTION_MAXNAMELEN) || put_user(datasize, (int __user *)(um + EBT_FUNCTION_MAXNAMELEN)) || - xt_data_to_user(um + entrysize, data, usersize, datasize)) + xt_data_to_user(um + entrysize, data, usersize, datasize, + XT_ALIGN(datasize))) return -EFAULT; return 0; @@ -1658,7 +1659,8 @@ static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr, if (match->compat_to_user(cm->data, m->data)) return -EFAULT; } else { - if (xt_data_to_user(cm->data, m->data, match->usersize, msize)) + if (xt_data_to_user(cm->data, m->data, match->usersize, msize, + COMPAT_XT_ALIGN(msize))) return -EFAULT; } @@ -1687,7 +1689,8 @@ static int compat_target_to_user(struct ebt_entry_target *t, if (target->compat_to_user(cm->data, t->data)) return -EFAULT; } else { - if (xt_data_to_user(cm->data, t->data, target->usersize, tsize)) + if (xt_data_to_user(cm->data, t->data, target->usersize, tsize, + COMPAT_XT_ALIGN(tsize))) return -EFAULT; } diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 8876b7da6884..d17769599c10 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -283,12 +283,13 @@ static int xt_obj_to_user(u16 __user *psize, u16 size, &U->u.user.revision, K->u.kernel.TYPE->revision) int xt_data_to_user(void __user *dst, const void *src, - int usersize, int size) + int usersize, int size, int aligned_size) { usersize = usersize ? : size; if (copy_to_user(dst, src, usersize)) return -EFAULT; - if (usersize != size && clear_user(dst + usersize, size - usersize)) + if (usersize != aligned_size && + clear_user(dst + usersize, aligned_size - usersize)) return -EFAULT; return 0; @@ -298,7 +299,9 @@ EXPORT_SYMBOL_GPL(xt_data_to_user); #define XT_DATA_TO_USER(U, K, TYPE, C_SIZE) \ xt_data_to_user(U->data, K->data, \ K->u.kernel.TYPE->usersize, \ - C_SIZE ? : K->u.kernel.TYPE->TYPE##size) + C_SIZE ? : K->u.kernel.TYPE->TYPE##size, \ + C_SIZE ? COMPAT_XT_ALIGN(C_SIZE) : \ + XT_ALIGN(K->u.kernel.TYPE->TYPE##size)) int xt_match_to_user(const struct xt_entry_match *m, struct xt_entry_match __user *u) -- cgit 1.4.1 From 591054469b3eef34bc097c30fae8ededddf8d796 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 15 May 2017 11:17:34 +0100 Subject: netfilter: nf_tables: revisit chain/object refcounting from elements Andreas reports that the following incremental update using our commit protocol doesn't work. # nft -f incremental-update.nft delete element ip filter client_to_any { 10.180.86.22 : goto CIn_1 } delete chain ip filter CIn_1 ... Error: Could not process rule: Device or resource busy The existing code is not well-integrated into the commit phase protocol, since element deletions do not result in refcount decrement from the preparation phase. This results in bogus EBUSY errors like the one above. Two new functions come with this patch: * nft_set_elem_activate() function is used from the abort path, to restore the set element refcounting on objects that occurred from the preparation phase. * nft_set_elem_deactivate() that is called from nft_del_setelem() to decrement set element refcounting on objects from the preparation phase in the commit protocol. The nft_data_uninit() has been renamed to nft_data_release() since this function does not uninitialize any data store in the data register, instead just releases the references to objects. Moreover, a new function nft_data_hold() has been introduced to be used from nft_set_elem_activate(). Reported-by: Andreas Schultz Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 2 +- net/netfilter/nf_tables_api.c | 82 ++++++++++++++++++++++++++++++++++----- net/netfilter/nft_bitwise.c | 4 +- net/netfilter/nft_cmp.c | 2 +- net/netfilter/nft_immediate.c | 5 ++- net/netfilter/nft_range.c | 4 +- 6 files changed, 81 insertions(+), 18 deletions(-) (limited to 'include') diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 028faec8fc27..8a8bab8d7b15 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -176,7 +176,7 @@ struct nft_data_desc { int nft_data_init(const struct nft_ctx *ctx, struct nft_data *data, unsigned int size, struct nft_data_desc *desc, const struct nlattr *nla); -void nft_data_uninit(const struct nft_data *data, enum nft_data_types type); +void nft_data_release(const struct nft_data *data, enum nft_data_types type); int nft_data_dump(struct sk_buff *skb, int attr, const struct nft_data *data, enum nft_data_types type, unsigned int len); diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 5f4a4d48b871..da314be0c048 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3627,9 +3627,9 @@ void nft_set_elem_destroy(const struct nft_set *set, void *elem, { struct nft_set_ext *ext = nft_set_elem_ext(set, elem); - nft_data_uninit(nft_set_ext_key(ext), NFT_DATA_VALUE); + nft_data_release(nft_set_ext_key(ext), NFT_DATA_VALUE); if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA)) - nft_data_uninit(nft_set_ext_data(ext), set->dtype); + nft_data_release(nft_set_ext_data(ext), set->dtype); if (destroy_expr && nft_set_ext_exists(ext, NFT_SET_EXT_EXPR)) nf_tables_expr_destroy(NULL, nft_set_ext_expr(ext)); if (nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF)) @@ -3638,6 +3638,18 @@ void nft_set_elem_destroy(const struct nft_set *set, void *elem, } EXPORT_SYMBOL_GPL(nft_set_elem_destroy); +/* Only called from commit path, nft_set_elem_deactivate() already deals with + * the refcounting from the preparation phase. + */ +static void nf_tables_set_elem_destroy(const struct nft_set *set, void *elem) +{ + struct nft_set_ext *ext = nft_set_elem_ext(set, elem); + + if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR)) + nf_tables_expr_destroy(NULL, nft_set_ext_expr(ext)); + kfree(elem); +} + static int nft_setelem_parse_flags(const struct nft_set *set, const struct nlattr *attr, u32 *flags) { @@ -3849,9 +3861,9 @@ err4: kfree(elem.priv); err3: if (nla[NFTA_SET_ELEM_DATA] != NULL) - nft_data_uninit(&data, d2.type); + nft_data_release(&data, d2.type); err2: - nft_data_uninit(&elem.key.val, d1.type); + nft_data_release(&elem.key.val, d1.type); err1: return err; } @@ -3896,6 +3908,53 @@ static int nf_tables_newsetelem(struct net *net, struct sock *nlsk, return err; } +/** + * nft_data_hold - hold a nft_data item + * + * @data: struct nft_data to release + * @type: type of data + * + * Hold a nft_data item. NFT_DATA_VALUE types can be silently discarded, + * NFT_DATA_VERDICT bumps the reference to chains in case of NFT_JUMP and + * NFT_GOTO verdicts. This function must be called on active data objects + * from the second phase of the commit protocol. + */ +static void nft_data_hold(const struct nft_data *data, enum nft_data_types type) +{ + if (type == NFT_DATA_VERDICT) { + switch (data->verdict.code) { + case NFT_JUMP: + case NFT_GOTO: + data->verdict.chain->use++; + break; + } + } +} + +static void nft_set_elem_activate(const struct net *net, + const struct nft_set *set, + struct nft_set_elem *elem) +{ + const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv); + + if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA)) + nft_data_hold(nft_set_ext_data(ext), set->dtype); + if (nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF)) + (*nft_set_ext_obj(ext))->use++; +} + +static void nft_set_elem_deactivate(const struct net *net, + const struct nft_set *set, + struct nft_set_elem *elem) +{ + const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv); + + if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA)) + nft_data_release(nft_set_ext_data(ext), set->dtype); + if (nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF)) + (*nft_set_ext_obj(ext))->use--; +} + static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set, const struct nlattr *attr) { @@ -3961,6 +4020,8 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set, kfree(elem.priv); elem.priv = priv; + nft_set_elem_deactivate(ctx->net, set, &elem); + nft_trans_elem(trans) = elem; list_add_tail(&trans->list, &ctx->net->nft.commit_list); return 0; @@ -3970,7 +4031,7 @@ err4: err3: kfree(elem.priv); err2: - nft_data_uninit(&elem.key.val, desc.type); + nft_data_release(&elem.key.val, desc.type); err1: return err; } @@ -4777,8 +4838,8 @@ static void nf_tables_commit_release(struct nft_trans *trans) nft_set_destroy(nft_trans_set(trans)); break; case NFT_MSG_DELSETELEM: - nft_set_elem_destroy(nft_trans_elem_set(trans), - nft_trans_elem(trans).priv, true); + nf_tables_set_elem_destroy(nft_trans_elem_set(trans), + nft_trans_elem(trans).priv); break; case NFT_MSG_DELOBJ: nft_obj_destroy(nft_trans_obj(trans)); @@ -5013,6 +5074,7 @@ static int nf_tables_abort(struct net *net, struct sk_buff *skb) case NFT_MSG_DELSETELEM: te = (struct nft_trans_elem *)trans->data; + nft_set_elem_activate(net, te->set, &te->elem); te->set->ops->activate(net, te->set, &te->elem); te->set->ndeact--; @@ -5498,7 +5560,7 @@ int nft_data_init(const struct nft_ctx *ctx, EXPORT_SYMBOL_GPL(nft_data_init); /** - * nft_data_uninit - release a nft_data item + * nft_data_release - release a nft_data item * * @data: struct nft_data to release * @type: type of data @@ -5506,7 +5568,7 @@ EXPORT_SYMBOL_GPL(nft_data_init); * Release a nft_data item. NFT_DATA_VALUE types can be silently discarded, * all others need to be released by calling this function. */ -void nft_data_uninit(const struct nft_data *data, enum nft_data_types type) +void nft_data_release(const struct nft_data *data, enum nft_data_types type) { if (type < NFT_DATA_VERDICT) return; @@ -5517,7 +5579,7 @@ void nft_data_uninit(const struct nft_data *data, enum nft_data_types type) WARN_ON(1); } } -EXPORT_SYMBOL_GPL(nft_data_uninit); +EXPORT_SYMBOL_GPL(nft_data_release); int nft_data_dump(struct sk_buff *skb, int attr, const struct nft_data *data, enum nft_data_types type, unsigned int len) diff --git a/net/netfilter/nft_bitwise.c b/net/netfilter/nft_bitwise.c index 96bd4f325b0f..fff8073e2a56 100644 --- a/net/netfilter/nft_bitwise.c +++ b/net/netfilter/nft_bitwise.c @@ -99,9 +99,9 @@ static int nft_bitwise_init(const struct nft_ctx *ctx, return 0; err2: - nft_data_uninit(&priv->xor, d2.type); + nft_data_release(&priv->xor, d2.type); err1: - nft_data_uninit(&priv->mask, d1.type); + nft_data_release(&priv->mask, d1.type); return err; } diff --git a/net/netfilter/nft_cmp.c b/net/netfilter/nft_cmp.c index 8c9d0fb19118..c2945eb3397c 100644 --- a/net/netfilter/nft_cmp.c +++ b/net/netfilter/nft_cmp.c @@ -211,7 +211,7 @@ nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]) return &nft_cmp_ops; err1: - nft_data_uninit(&data, desc.type); + nft_data_release(&data, desc.type); return ERR_PTR(-EINVAL); } diff --git a/net/netfilter/nft_immediate.c b/net/netfilter/nft_immediate.c index 728baf88295a..4717d7796927 100644 --- a/net/netfilter/nft_immediate.c +++ b/net/netfilter/nft_immediate.c @@ -65,7 +65,7 @@ static int nft_immediate_init(const struct nft_ctx *ctx, return 0; err1: - nft_data_uninit(&priv->data, desc.type); + nft_data_release(&priv->data, desc.type); return err; } @@ -73,7 +73,8 @@ static void nft_immediate_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) { const struct nft_immediate_expr *priv = nft_expr_priv(expr); - return nft_data_uninit(&priv->data, nft_dreg_to_type(priv->dreg)); + + return nft_data_release(&priv->data, nft_dreg_to_type(priv->dreg)); } static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr) diff --git a/net/netfilter/nft_range.c b/net/netfilter/nft_range.c index 9edc74eedc10..cedb96c3619f 100644 --- a/net/netfilter/nft_range.c +++ b/net/netfilter/nft_range.c @@ -102,9 +102,9 @@ static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr priv->len = desc_from.len; return 0; err2: - nft_data_uninit(&priv->data_to, desc_to.type); + nft_data_release(&priv->data_to, desc_to.type); err1: - nft_data_uninit(&priv->data_from, desc_from.type); + nft_data_release(&priv->data_from, desc_from.type); return err; } -- cgit 1.4.1 From c953d63548207a085abcb12a15fefc8a11ffdf0a Mon Sep 17 00:00:00 2001 From: Gao Feng Date: Tue, 16 May 2017 09:30:18 +0800 Subject: ebtables: arpreply: Add the standard target sanity check The info->target comes from userspace and it would be used directly. So we need to add the sanity check to make sure it is a valid standard target, although the ebtables tool has already checked it. Kernel needs to validate anything coming from userspace. If the target is set as an evil value, it would break the ebtables and cause a panic. Because the non-standard target is treated as one offset. Now add one helper function ebt_invalid_target, and we would replace the macro INVALID_TARGET later. Signed-off-by: Gao Feng Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter_bridge/ebtables.h | 5 +++++ net/bridge/netfilter/ebt_arpreply.c | 3 +++ 2 files changed, 8 insertions(+) (limited to 'include') diff --git a/include/linux/netfilter_bridge/ebtables.h b/include/linux/netfilter_bridge/ebtables.h index a30efb437e6d..e0cbf17af780 100644 --- a/include/linux/netfilter_bridge/ebtables.h +++ b/include/linux/netfilter_bridge/ebtables.h @@ -125,4 +125,9 @@ extern unsigned int ebt_do_table(struct sk_buff *skb, /* True if the target is not a standard target */ #define INVALID_TARGET (info->target < -NUM_STANDARD_TARGETS || info->target >= 0) +static inline bool ebt_invalid_target(int target) +{ + return (target < -NUM_STANDARD_TARGETS || target >= 0); +} + #endif diff --git a/net/bridge/netfilter/ebt_arpreply.c b/net/bridge/netfilter/ebt_arpreply.c index 5929309beaa1..db85230e49c3 100644 --- a/net/bridge/netfilter/ebt_arpreply.c +++ b/net/bridge/netfilter/ebt_arpreply.c @@ -68,6 +68,9 @@ static int ebt_arpreply_tg_check(const struct xt_tgchk_param *par) if (e->ethproto != htons(ETH_P_ARP) || e->invflags & EBT_IPROTO) return -EINVAL; + if (ebt_invalid_target(info->target)) + return -EINVAL; + return 0; } -- cgit 1.4.1