From: Tyler Hicks Date: Thu, 5 Jul 2018 18:49:23 +0000 (+0000) Subject: ipv4: Return EINVAL when ping_group_range sysctl doesn't map to user ns X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=70ba5b6db96ff7324b8cfc87e0d0383cf59c9677;p=linux.git ipv4: Return EINVAL when ping_group_range sysctl doesn't map to user ns The low and high values of the net.ipv4.ping_group_range sysctl were being silently forced to the default disabled state when a write to the sysctl contained GIDs that didn't map to the associated user namespace. Confusingly, the sysctl's write operation would return success and then a subsequent read of the sysctl would indicate that the low and high values are the overflowgid. This patch changes the behavior by clearly returning an error when the sysctl write operation receives a GID range that doesn't map to the associated user namespace. In such a situation, the previous value of the sysctl is preserved and that range will be returned in a subsequent read of the sysctl. Signed-off-by: Tyler Hicks Signed-off-by: David S. Miller --- diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index af0a857d8352f..5fa335fd38525 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -189,8 +189,9 @@ static int ipv4_ping_group_range(struct ctl_table *table, int write, if (write && ret == 0) { low = make_kgid(user_ns, urange[0]); high = make_kgid(user_ns, urange[1]); - if (!gid_valid(low) || !gid_valid(high) || - (urange[1] < urange[0]) || gid_lt(high, low)) { + if (!gid_valid(low) || !gid_valid(high)) + return -EINVAL; + if (urange[1] < urange[0] || gid_lt(high, low)) { low = make_kgid(&init_user_ns, 1); high = make_kgid(&init_user_ns, 0); }