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| author | Liping Zhang <liping.zhang@spreadtrum.com> | 2016-09-12 22:21:36 +0800 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-09-12 20:00:23 +0200 |
| commit | 2e917d602acd9e3e8c6e4c43b213c8929d986503 (patch) | |
| tree | 1d7ffcad09e03541892e6eb11fb150f30208a323 | |
| parent | 8e8118f893138d4cc3d4dbf4163d7497fca54a9d (diff) | |
| download | linux-2e917d602acd9e3e8c6e4c43b213c8929d986503.tar.gz linux-2e917d602acd9e3e8c6e4c43b213c8929d986503.tar.bz2 linux-2e917d602acd9e3e8c6e4c43b213c8929d986503.zip | |
netfilter: nft_numgen: fix race between num generate and store it
After we generate a new number, we still use the priv->counter and
store it to the dreg. This is not correct, another cpu may already
change it to a new number. So we must use the generated number, not
the priv->counter itself.
Fixes: 91dbc6be0a62 ("netfilter: nf_tables: add number generator expression")
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| -rw-r--r-- | net/netfilter/nft_numgen.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/netfilter/nft_numgen.c b/net/netfilter/nft_numgen.c index f51a3ede3932..f173ebec30a7 100644 --- a/net/netfilter/nft_numgen.c +++ b/net/netfilter/nft_numgen.c @@ -37,7 +37,7 @@ static void nft_ng_inc_eval(const struct nft_expr *expr, nval = (oval + 1 < priv->modulus) ? oval + 1 : 0; } while (atomic_cmpxchg(&priv->counter, oval, nval) != oval); - memcpy(®s->data[priv->dreg], &priv->counter, sizeof(u32)); + regs->data[priv->dreg] = nval; } static const struct nla_policy nft_ng_policy[NFTA_NG_MAX + 1] = { |