diff options
| author | Philip Whineray <phil@firehol.org> | 2015-11-22 11:35:07 +0000 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2015-11-25 13:54:09 +0100 |
| commit | f13f2aeed154da8e48f90b85e720f8ba39b1e881 (patch) | |
| tree | 3e7035ef8a97bcc475381fb7c5227e087e45a70a /net/netfilter/x_tables.c | |
| parent | daaa7d647f81f3f1494d9a9029d611b666d63181 (diff) | |
| download | linux-f13f2aeed154da8e48f90b85e720f8ba39b1e881.tar.gz | |
netfilter: Set /proc/net entries owner to root in namespace
Various files are owned by root with 0440 permission. Reading them is
impossible in an unprivileged user namespace, interfering with firewall
tools. For instance, iptables-save relies on /proc/net/ip_tables_names
contents to dump only loaded tables.
This patch assigned ownership of the following files to root in the
current namespace:
- /proc/net/*_tables_names
- /proc/net/*_tables_matches
- /proc/net/*_tables_targets
- /proc/net/nf_conntrack
- /proc/net/nf_conntrack_expect
- /proc/net/netfilter/nfnetlink_log
A mapping for root must be available, so this order should be followed:
unshare(CLONE_NEWUSER);
/* Setup the mapping */
unshare(CLONE_NEWNET);
Signed-off-by: Philip Whineray <phil@firehol.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/x_tables.c')
| -rw-r--r-- | net/netfilter/x_tables.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index d4aaad747ea99..c8a0b7da5ff46 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -26,6 +26,7 @@ #include <linux/mm.h> #include <linux/slab.h> #include <linux/audit.h> +#include <linux/user_namespace.h> #include <net/net_namespace.h> #include <linux/netfilter/x_tables.h> @@ -1226,6 +1227,8 @@ int xt_proto_init(struct net *net, u_int8_t af) #ifdef CONFIG_PROC_FS char buf[XT_FUNCTION_MAXNAMELEN]; struct proc_dir_entry *proc; + kuid_t root_uid; + kgid_t root_gid; #endif if (af >= ARRAY_SIZE(xt_prefix)) @@ -1233,12 +1236,17 @@ int xt_proto_init(struct net *net, u_int8_t af) #ifdef CONFIG_PROC_FS + root_uid = make_kuid(net->user_ns, 0); + root_gid = make_kgid(net->user_ns, 0); + strlcpy(buf, xt_prefix[af], sizeof(buf)); strlcat(buf, FORMAT_TABLES, sizeof(buf)); proc = proc_create_data(buf, 0440, net->proc_net, &xt_table_ops, (void *)(unsigned long)af); if (!proc) goto out; + if (uid_valid(root_uid) && gid_valid(root_gid)) + proc_set_user(proc, root_uid, root_gid); strlcpy(buf, xt_prefix[af], sizeof(buf)); strlcat(buf, FORMAT_MATCHES, sizeof(buf)); @@ -1246,6 +1254,8 @@ int xt_proto_init(struct net *net, u_int8_t af) (void *)(unsigned long)af); if (!proc) goto out_remove_tables; + if (uid_valid(root_uid) && gid_valid(root_gid)) + proc_set_user(proc, root_uid, root_gid); strlcpy(buf, xt_prefix[af], sizeof(buf)); strlcat(buf, FORMAT_TARGETS, sizeof(buf)); @@ -1253,6 +1263,8 @@ int xt_proto_init(struct net *net, u_int8_t af) (void *)(unsigned long)af); if (!proc) goto out_remove_matches; + if (uid_valid(root_uid) && gid_valid(root_gid)) + proc_set_user(proc, root_uid, root_gid); #endif return 0; |