net/ipv4: ping_group_range: allow GID from 2147483648 to 4294967294

With this commit, all the GIDs ("0 4294967294") can be written to the
"net.ipv4.ping_group_range" sysctl.

Note that 4294967295 (0xffffffff) is an invalid GID (see gid_valid() in
include/linux/uidgid.h), and an attempt to register this number will cause
-EINVAL.

Prior to this commit, only up to GID 2147483647 could be covered.
Documentation/networking/ip-sysctl.rst had "0 4294967295" as an example
value, but this example was wrong and causing -EINVAL.

Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind")
Co-developed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index 6ec06a33688a68c40dd882efedcdbe4480a1c5ec..80b8f73a0244f4682967e74bb2edec010bf0c27a 100644 (file)
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -1352,8 +1352,8 @@ ping_group_range - 2 INTEGERS
        Restrict ICMP_PROTO datagram sockets to users in the group range.
        The default is "1 0", meaning, that nobody (not even root) may
        create ping sockets.  Setting it to "100 100" would grant permissions
-       to the single group. "0 4294967295" would enable it for the world, "100
-       4294967295" would enable it for the users, but not daemons.
+       to the single group. "0 4294967294" would enable it for the world, "100
+       4294967294" would enable it for the users, but not daemons.
 
 tcp_early_demux - BOOLEAN
        Enable early demux for established TCP sockets.

diff --git a/include/net/ping.h b/include/net/ping.h
index 9233ad3de0ade20a0d884723f43109cea2b24896..bc7779262e60350e2748c74731a5d6d71f1b9455 100644 (file)
--- a/include/net/ping.h
+++ b/include/net/ping.h
@@ -16,11 +16,7 @@
 #define PING_HTABLE_SIZE       64
 #define PING_HTABLE_MASK       (PING_HTABLE_SIZE-1)
 
-/*
- * gid_t is either uint or ushort.  We want to pass it to
- * proc_dointvec_minmax(), so it must not be larger than MAX_INT
- */
-#define GID_T_MAX (((gid_t)~0U) >> 1)
+#define GID_T_MAX (((gid_t)~0U) - 1)
 
 /* Compatibility glue so we can support IPv6 when it's compiled as a module */
 struct pingv6_ops {

diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 40fe70fc2015d5ce0a8d2791a714f1324ecb231e..88dfe51e68f3cc1f2e0cc21ccd4ad4d1bd526e02 100644 (file)
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -34,8 +34,8 @@ static int ip_ttl_min = 1;
 static int ip_ttl_max = 255;
 static int tcp_syn_retries_min = 1;
 static int tcp_syn_retries_max = MAX_TCP_SYNCNT;
-static int ip_ping_group_range_min[] = { 0, 0 };
-static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
+static unsigned long ip_ping_group_range_min[] = { 0, 0 };
+static unsigned long ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
 static u32 u32_max_div_HZ = UINT_MAX / HZ;
 static int one_day_secs = 24 * 3600;
 static u32 fib_multipath_hash_fields_all_mask __maybe_unused =
@@ -165,7 +165,7 @@ static int ipv4_ping_group_range(struct ctl_table *table, int write,
 {
        struct user_namespace *user_ns = current_user_ns();
        int ret;
-       gid_t urange[2];
+       unsigned long urange[2];
        kgid_t low, high;
        struct ctl_table tmp = {
                .data = &urange,
@@ -178,7 +178,7 @@ static int ipv4_ping_group_range(struct ctl_table *table, int write,
        inet_get_ping_group_range_table(table, &low, &high);
        urange[0] = from_kgid_munged(user_ns, low);
        urange[1] = from_kgid_munged(user_ns, high);
-       ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
+       ret = proc_doulongvec_minmax(&tmp, write, buffer, lenp, ppos);
 
        if (write && ret == 0) {
                low = make_kgid(user_ns, urange[0]);