Subject: Re: [PATCH bpf 1/3] bpf, sockmap: Check for any of tcp_bpf_prots when cloning a listener

From: Dan Carpenter <[email-masked]>
Date: Sat, 14 Jan 2023 11:04:30 +0300

Hi Jakub,

url:    https://github.com/intel-lab-lkp/linux/commits/Jakub-Sitnicki/bpf-sockmap-Check-for-any-of-tcp_bpf_prots-when-cloning-a-listener/20230113-230728
base:   e7895f017b79410bf4591396a733b876dc1e0e9d
patch link:    https://lore.kernel.org/r/20230113-sockmap-fix-v1-1-d3cad092ee10%40cloudflare.com
patch subject: [PATCH bpf 1/3] bpf, sockmap: Check for any of tcp_bpf_prots when cloning a listener
config: i386-randconfig-m021
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <[email-masked]>
| Reported-by: Dan Carpenter <[email-masked]>

smatch warnings:
net/ipv4/tcp_bpf.c:644 tcp_bpf_clone() error: buffer overflow 'tcp_bpf_prots' 2 <= 2

vim +/tcp_bpf_prots +644 net/ipv4/tcp_bpf.c

604326b41a6fb9 Daniel Borkmann 2018-10-13  634  
e80251555f0bef Jakub Sitnicki  2020-02-18  635  /* If a child got cloned from a listening socket that had tcp_bpf
e80251555f0bef Jakub Sitnicki  2020-02-18  636   * protocol callbacks installed, we need to restore the callbacks to
e80251555f0bef Jakub Sitnicki  2020-02-18  637   * the default ones because the child does not inherit the psock state
e80251555f0bef Jakub Sitnicki  2020-02-18  638   * that tcp_bpf callbacks expect.
e80251555f0bef Jakub Sitnicki  2020-02-18  639   */
e80251555f0bef Jakub Sitnicki  2020-02-18  640  void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)
e80251555f0bef Jakub Sitnicki  2020-02-18  641  {
e80251555f0bef Jakub Sitnicki  2020-02-18  642  	struct proto *prot = newsk->sk_prot;
e80251555f0bef Jakub Sitnicki  2020-02-18  643  
c2e74657613125 Jakub Sitnicki  2023-01-13 @644  	if (tcp_bpf_prots[0] <= prot && prot < tcp_bpf_prots[ARRAY_SIZE(tcp_bpf_prots)])
                                                                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
What?  Also I suspect this might cause a compile error for Clang builds.

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests