11:03 p.m.
Hi Arjun,
url:
https://github.com/0day-ci/linux/commits/Arjun-Roy/tcp-Sanitize-CMSG-flag...
base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git
e4b62cf7559f2ef9a022de235e5a09a8d7ded520
config: x86_64-randconfig-m001-20210209 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp(a)intel.com>
Reported-by: Dan Carpenter <dan.carpenter(a)oracle.com>
smatch warnings:
net/ipv4/tcp.c:4158 do_tcp_getsockopt() warn: check for integer overflow 'len'
vim +/len +4158 net/ipv4/tcp.c
3fdadf7d27e3fb Dmitry Mishin 2006-03-20 3896 static int
do_tcp_getsockopt(struct sock *sk, int level,
3fdadf7d27e3fb Dmitry Mishin 2006-03-20 3897 int optname, char __user
*optval, int __user *optlen)
^1da177e4c3f41 Linus Torvalds 2005-04-16 3898 {
295f7324ff8d9e Arnaldo Carvalho de Melo 2005-08-09 3899 struct inet_connection_sock
*icsk = inet_csk(sk);
^1da177e4c3f41 Linus Torvalds 2005-04-16 3900 struct tcp_sock *tp =
tcp_sk(sk);
6fa251663069e0 Nikolay Borisov 2016-02-03 3901 struct net *net =
sock_net(sk);
^1da177e4c3f41 Linus Torvalds 2005-04-16 3902 int val, len;
"len" is int.
[ snip ]
05255b823a6173 Eric Dumazet 2018-04-27 4146 #ifdef CONFIG_MMU
05255b823a6173 Eric Dumazet 2018-04-27 4147 case TCP_ZEROCOPY_RECEIVE: {
7eeba1706eba6d Arjun Roy 2021-01-20 4148 struct
scm_timestamping_internal tss;
e0fecb289ad3fd Arjun Roy 2020-12-10 4149 struct tcp_zerocopy_receive zc
= {};
05255b823a6173 Eric Dumazet 2018-04-27 4150 int err;
05255b823a6173 Eric Dumazet 2018-04-27 4151
05255b823a6173 Eric Dumazet 2018-04-27 4152 if (get_user(len, optlen))
05255b823a6173 Eric Dumazet 2018-04-27 4153 return -EFAULT;
c8856c05145490 Arjun Roy 2020-02-14 4154 if (len <
offsetofend(struct tcp_zerocopy_receive, length))
05255b823a6173 Eric Dumazet 2018-04-27 4155 return -EINVAL;
The problem is that negative values of "len" are type promoted to high
positive values. So the fix is to write this as:
if (len < 0 || len < offsetofend(struct tcp_zerocopy_receive, length))
return -EINVAL;
110912bdf28392 Arjun Roy 2021-02-11 4156 if (unlikely(len >
sizeof(zc))) {
110912bdf28392 Arjun Roy 2021-02-11 4157 err =
check_zeroed_user(optval + sizeof(zc),
110912bdf28392 Arjun Roy 2021-02-11 @4158 len - sizeof(zc));
^^^^^^^^^^^^^^^^
Potentially "len - a negative value".
110912bdf28392 Arjun Roy 2021-02-11 4159 if (err < 1)
110912bdf28392 Arjun Roy 2021-02-11 4160 return err == 0 ? -EINVAL :
err;
c8856c05145490 Arjun Roy 2020-02-14 4161 len = sizeof(zc);
0b7f41f68710cc Arjun Roy 2020-02-25 4162 if (put_user(len, optlen))
0b7f41f68710cc Arjun Roy 2020-02-25 4163 return -EFAULT;
0b7f41f68710cc Arjun Roy 2020-02-25 4164 }
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0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org