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| author | Florian Westphal <fw@strlen.de> | 2023-07-20 00:29:58 +0200 |
|---|---|---|
| committer | Florian Westphal <fw@strlen.de> | 2023-07-20 11:56:50 +0200 |
| commit | ddbd8be68941985f166f5107109a90ce13147c44 (patch) | |
| tree | d040cbc705cc1ab134dfc75e3e83ea87ec328fe7 /net/netfilter | |
| parent | ac528649f7c63bc233cc0d33cff11f767cc666e3 (diff) | |
| download | linux-ddbd8be68941985f166f5107109a90ce13147c44.tar.gz linux-ddbd8be68941985f166f5107109a90ce13147c44.tar.bz2 linux-ddbd8be68941985f166f5107109a90ce13147c44.zip | |
netfilter: nf_tables: fix spurious set element insertion failure
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>
Diffstat (limited to 'net/netfilter')
| -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 237f739da3ca..79c7eee33dcd 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -10517,6 +10517,9 @@ 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) { |