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| author | Florian Westphal <fw@strlen.de> | 2023-07-20 01:29:58 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-07-27 09:44:41 +0300 |
| commit | 533193a23914558127190e7bf7cb505ab6389acd (patch) | |
| tree | 3b9c0a1192db409f7c843a2778255d9b49abc2f2 | |
| parent | a6f1988780a7c9e5f54a1d6d363db99e850106fc (diff) | |
| download | linux-533193a23914558127190e7bf7cb505ab6389acd.tar.xz | |
netfilter: nf_tables: fix spurious set element insertion failure
[ Upstream commit ddbd8be68941985f166f5107109a90ce13147c44 ]
On some platforms there is a padding hole in the nft_verdict
structure, between the verdict code and the chain pointer.
On element insertion, if the new element clashes with an existing one and
NLM_F_EXCL flag isn't set, we want to ignore the -EEXIST error as long as
the data associated with duplicated element is the same as the existing
one. The data equality check uses memcmp.
For normal data (NFT_DATA_VALUE) this works fine, but for NFT_DATA_VERDICT
padding area leads to spurious failure even if the verdict data is the
same.
This then makes the insertion fail with 'already exists' error, even
though the new "key : data" matches an existing entry and userspace
told the kernel that it doesn't want to receive an error indication.
Fixes: c016c7e45ddf ("netfilter: nf_tables: honor NLM_F_EXCL flag in set element insertion")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/netfilter/nf_tables_api.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index d56f5d7fa545..9c3a9e3f1ede 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -8914,6 +8914,9 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data, if (!tb[NFTA_VERDICT_CODE]) return -EINVAL; + + /* zero padding hole for memcmp */ + memset(data, 0, sizeof(*data)); data->verdict.code = ntohl(nla_get_be32(tb[NFTA_VERDICT_CODE])); switch (data->verdict.code) { |