From b49d3c1e1c948d76d64790abe9acffa9fa747d19 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 25 Nov 2012 09:44:29 +0000 Subject: [PATCH] net: ipmr: limit MRT_TABLE identifiers Name of pimreg devices are built from following format : char name[IFNAMSIZ]; // IFNAMSIZ == 16 sprintf(name, "pimreg%u", mrt->id); We must therefore limit mrt->id to 9 decimal digits or risk a buffer overflow and a crash. Restrict table identifiers in [0 ... 999999999] interval. Reported-by: Chen Gang Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/ipmr.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 6168c4d..3eab2b2 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -1318,6 +1318,10 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsi if (get_user(v, (u32 __user *)optval)) return -EFAULT; + /* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */ + if (v != RT_TABLE_DEFAULT && v >= 1000000000) + return -EINVAL; + rtnl_lock(); ret = 0; if (sk == rtnl_dereference(mrt->mroute_sk)) { -- 2.7.4