Re: [PATCH linux v2] net/ipv4: ping_group_range: allow GID from 2147483648 to 4294967294

[Akihiro Suda]

Thanks, submitted v3 with your suggestions
https://patchwork.kernel.org/project/netdevbpf/patch/20230601031305.55901-1-akihiro.suda.cz@xxxxxxxxxxxxx/

2023年6月1日(木) 10:27 Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>:
>
> From: ~akihirosuda <akihirosuda@xxxxxxxxx>
> Date: Wed, 31 May 2023 19:42:49 +0900
> > From: Akihiro Suda <akihiro.suda.cz@xxxxxxxxxxxxx>
> >
> > 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.
> >
> > v1->v2: Simplified the patch (Thanks to Kuniyuki Iwashima for suggestion)
>
> Changelog should be placed under '---'.
>
> Also could you use 'net' instead of 'linux' in Subject so that
> patchwork will be happy ?
>
> https://patchwork.kernel.org/project/netdevbpf/patch/168557950756.14226.6470993129419598644-0@xxxxxxxxx/
>
>
> >
> > Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind")
> > Signed-off-by: Akihiro Suda <akihiro.suda.cz@xxxxxxxxxxxxx>
> > ---
> >  Documentation/networking/ip-sysctl.rst | 4 ++--
> >  include/net/ping.h                     | 6 +-----
> >  net/ipv4/sysctl_net_ipv4.c             | 8 ++++----
> >  3 files changed, 7 insertions(+), 11 deletions(-)
> >
> > diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
> > index 6ec06a33688a..80b8f73a0244 100644
> > --- 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 9233ad3de0ad..bc7779262e60 100644
> > --- 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 40fe70fc2015..bb49d9407c45 100644
> > --- 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 long ip_ping_group_range_min[] = { 0, 0 };
> > +static long ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
>
> nit: s/long/unsigned long/
>
> Then, add
>
> Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
>
> Thanks!
>
>
> >  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]);
> > --
> > 2.38.4
>