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| author | Qi Tang <tpluszz77@gmail.com> | 2026-03-31 09:17:12 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-04-11 15:24:34 +0300 |
| commit | fd002ff2ea030cbfb0188a11b3c60ce7f84485f4 (patch) | |
| tree | 914cd86be1ece27af8af002f8bbd754f2ab624ba /net | |
| parent | 2c16e4d64dd91227742dfe196a3e7b0568bef65a (diff) | |
| download | linux-fd002ff2ea030cbfb0188a11b3c60ce7f84485f4.tar.xz | |
netfilter: ctnetlink: zero expect NAT fields when CTA_EXPECT_NAT absent
[ Upstream commit 35177c6877134a21315f37d57a5577846225623e ]
ctnetlink_alloc_expect() allocates expectations from a non-zeroing
slab cache via nf_ct_expect_alloc(). When CTA_EXPECT_NAT is not
present in the netlink message, saved_addr and saved_proto are
never initialized. Stale data from a previous slab occupant can
then be dumped to userspace by ctnetlink_exp_dump_expect(), which
checks these fields to decide whether to emit CTA_EXPECT_NAT.
The safe sibling nf_ct_expect_init(), used by the packet path,
explicitly zeroes these fields.
Zero saved_addr, saved_proto and dir in the else branch, guarded
by IS_ENABLED(CONFIG_NF_NAT) since these fields only exist when
NAT is enabled.
Confirmed by priming the expect slab with NAT-bearing expectations,
freeing them, creating a new expectation without CTA_EXPECT_NAT,
and observing that the ctnetlink dump emits a spurious
CTA_EXPECT_NAT containing stale data from the prior allocation.
Fixes: 076a0ca02644 ("netfilter: ctnetlink: add NAT support for expectations")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Qi Tang <tpluszz77@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nf_conntrack_netlink.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 3fe37bdd625e..1fd4371ff636 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -3571,6 +3571,12 @@ ctnetlink_alloc_expect(const struct nlattr * const cda[], struct nf_conn *ct, exp, nf_ct_l3num(ct)); if (err < 0) goto err_out; +#if IS_ENABLED(CONFIG_NF_NAT) + } else { + memset(&exp->saved_addr, 0, sizeof(exp->saved_addr)); + memset(&exp->saved_proto, 0, sizeof(exp->saved_proto)); + exp->dir = 0; +#endif } return exp; err_out: |