[PATCH 5.4 178/191] gtp: avoid zero size hashtable

Greg Kroah-Hartman
2020-01-02T22:55:59Z

From: Taehee Yoo <ap420073@gmail.com>

[ Upstream commit 6a902c0f31993ab02e1b6ea7085002b9c9083b6a ]

GTP default hashtable size is 1024 and userspace could set specific
hashtable size with IFLA_GTP_PDP_HASHSIZE. If hashtable size is set to 0
from userspace, hashtable will not work and panic will occur.

Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/gtp.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -660,10 +660,13 @@ static int gtp_newlink(struct net *src_n
if (err < 0)
return err;

- if (!data[IFLA_GTP_PDP_HASHSIZE])
+ if (!data[IFLA_GTP_PDP_HASHSIZE]) {
hashsize = 1024;
- else
+ } else {
hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
+ if (!hashsize)
+ hashsize = 1024;
+ }

err = gtp_hashtable_new(gtp, hashsize);
if (err < 0)