From: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
To: Pablo Neira Ayuso <pablo@netfilter.org>,
Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>,
Florian Westphal <fw@strlen.de>,
"David S. Miller" <davem@davemloft.net>,
netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Lukasz Pawelczyk <havner@gmail.com>,
Lukasz Pawelczyk <l.pawelczyk@samsung.com>
Subject: [PATCH v3] netfilter: xt_owner: Add supplementary groups option
Date: Fri, 10 May 2019 13:46:22 +0200 [thread overview]
Message-ID: <20190510114622.831-1-l.pawelczyk@samsung.com> (raw)
In-Reply-To: CGME20190510114627eucas1p25476833d2d375b113353741c18aecd92@eucas1p2.samsung.com
The XT_OWNER_SUPPL_GROUPS flag causes GIDs specified with XT_OWNER_GID
to be also checked in the supplementary groups of a process.
f_cred->group_info cannot be modified during its lifetime and f_cred
holds a reference to it so it's safe to use.
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
---
Changes from v2:
- XT_SUPPL_GROUPS -> XT_OWNER_SUPPL_GROUPS
- clarified group_info usage in the commit log
Changes from v1:
- complementary -> supplementary
include/uapi/linux/netfilter/xt_owner.h | 7 ++++---
net/netfilter/xt_owner.c | 23 ++++++++++++++++++++---
2 files changed, 24 insertions(+), 6 deletions(-)
diff --git a/include/uapi/linux/netfilter/xt_owner.h b/include/uapi/linux/netfilter/xt_owner.h
index fa3ad84957d5..9e98c09eda32 100644
--- a/include/uapi/linux/netfilter/xt_owner.h
+++ b/include/uapi/linux/netfilter/xt_owner.h
@@ -5,9 +5,10 @@
#include <linux/types.h>
enum {
- XT_OWNER_UID = 1 << 0,
- XT_OWNER_GID = 1 << 1,
- XT_OWNER_SOCKET = 1 << 2,
+ XT_OWNER_UID = 1 << 0,
+ XT_OWNER_GID = 1 << 1,
+ XT_OWNER_SOCKET = 1 << 2,
+ XT_OWNER_SUPPL_GROUPS = 1 << 3,
};
struct xt_owner_match_info {
diff --git a/net/netfilter/xt_owner.c b/net/netfilter/xt_owner.c
index 46686fb73784..a8784502aca6 100644
--- a/net/netfilter/xt_owner.c
+++ b/net/netfilter/xt_owner.c
@@ -91,11 +91,28 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par)
}
if (info->match & XT_OWNER_GID) {
+ unsigned int i, match = false;
kgid_t gid_min = make_kgid(net->user_ns, info->gid_min);
kgid_t gid_max = make_kgid(net->user_ns, info->gid_max);
- if ((gid_gte(filp->f_cred->fsgid, gid_min) &&
- gid_lte(filp->f_cred->fsgid, gid_max)) ^
- !(info->invert & XT_OWNER_GID))
+ struct group_info *gi = filp->f_cred->group_info;
+
+ if (gid_gte(filp->f_cred->fsgid, gid_min) &&
+ gid_lte(filp->f_cred->fsgid, gid_max))
+ match = true;
+
+ if (!match && (info->match & XT_OWNER_SUPPL_GROUPS) && gi) {
+ for (i = 0; i < gi->ngroups; ++i) {
+ kgid_t group = gi->gid[i];
+
+ if (gid_gte(group, gid_min) &&
+ gid_lte(group, gid_max)) {
+ match = true;
+ break;
+ }
+ }
+ }
+
+ if (match ^ !(info->invert & XT_OWNER_GID))
return false;
}
--
2.20.1
next parent reply other threads:[~2019-05-10 11:46 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20190510114627eucas1p25476833d2d375b113353741c18aecd92@eucas1p2.samsung.com>
2019-05-10 11:46 ` Lukasz Pawelczyk [this message]
2019-05-31 15:54 ` [PATCH v3] netfilter: xt_owner: Add supplementary groups option Pablo Neira Ayuso
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