[PATCH nf-next 1/2] netfilter: nft_compat: put back match/target module if init fail

[Liping Zhang]

From: Liping Zhang <liping.zh...@spreadtrum.com>

If the user specify the invalid NFTA_MATCH_INFO/NFTA_TARGET_INFO attr
or memory alloc fail, we should call module_put to the related match
or target. Otherwise, we cannot remove the module even nobody use it.

Signed-off-by: Liping Zhang <liping.zh...@spreadtrum.com>
---
 net/netfilter/nft_compat.c | 34 ++++++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/net/netfilter/nft_compat.c b/net/netfilter/nft_compat.c
index 6228c42..d74adf4 100644
--- a/net/netfilter/nft_compat.c
+++ b/net/netfilter/nft_compat.c
@@ -634,6 +634,7 @@ nft_match_select_ops(const struct nft_ctx *ctx,
        struct xt_match *match;
        char *mt_name;
        u32 rev, family;
+       int err;
 
        if (tb[NFTA_MATCH_NAME] == NULL ||
            tb[NFTA_MATCH_REV] == NULL ||
@@ -660,13 +661,17 @@ nft_match_select_ops(const struct nft_ctx *ctx,
        if (IS_ERR(match))
                return ERR_PTR(-ENOENT);
 
-       if (match->matchsize > nla_len(tb[NFTA_MATCH_INFO]))
-               return ERR_PTR(-EINVAL);
+       if (match->matchsize > nla_len(tb[NFTA_MATCH_INFO])) {
+               err = -EINVAL;
+               goto err;
+       }
 
        /* This is the first time we use this match, allocate operations */
        nft_match = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
-       if (nft_match == NULL)
-               return ERR_PTR(-ENOMEM);
+       if (nft_match == NULL) {
+               err = -ENOMEM;
+               goto err;
+       }
 
        nft_match->ops.type = &nft_match_type;
        nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
@@ -680,6 +685,10 @@ nft_match_select_ops(const struct nft_ctx *ctx,
        list_add(&nft_match->head, &nft_match_list);
 
        return &nft_match->ops;
+
+err:
+       module_put(match->me);
+       return ERR_PTR(err);
 }
 
 static void nft_match_release(void)
@@ -717,6 +726,7 @@ nft_target_select_ops(const struct nft_ctx *ctx,
        struct xt_target *target;
        char *tg_name;
        u32 rev, family;
+       int err;
 
        if (tb[NFTA_TARGET_NAME] == NULL ||
            tb[NFTA_TARGET_REV] == NULL ||
@@ -743,13 +753,17 @@ nft_target_select_ops(const struct nft_ctx *ctx,
        if (IS_ERR(target))
                return ERR_PTR(-ENOENT);
 
-       if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO]))
-               return ERR_PTR(-EINVAL);
+       if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO])) {
+               err = -EINVAL;
+               goto err;
+       }
 
        /* This is the first time we use this target, allocate operations */
        nft_target = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
-       if (nft_target == NULL)
-               return ERR_PTR(-ENOMEM);
+       if (nft_target == NULL) {
+               err = -ENOMEM;
+               goto err;
+       }
 
        nft_target->ops.type = &nft_target_type;
        nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize));
@@ -767,6 +781,10 @@ nft_target_select_ops(const struct nft_ctx *ctx,
        list_add(&nft_target->head, &nft_target_list);
 
        return &nft_target->ops;
+
+err:
+       module_put(target->me);
+       return ERR_PTR(err);
 }
 
 static void nft_target_release(void)
-- 
2.5.5


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