Re: [PATCH] net: ipv6: fix slab-out-of-bounda Read in xfrm6_tunnel_alloc_spi

[kernel test robot]

Hi K,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on ipsec/master]
[also build test WARNING on ipsec-next/master sparc-next/master net-next/master 
net/master v5.8-rc6 next-20200724]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    
https://github.com/0day-ci/linux/commits/B-K-Karthik/net-ipv6-fix-slab-out-of-bounda-Read-in-xfrm6_tunnel_alloc_spi/20200725-204631
base:   https://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec.git 
master
config: x86_64-randconfig-r032-20200726 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 
8bf4c1f4fb257774f66c8cda07adc6c5e8668326)
reproduce (this is a W=1 build):
        wget 
https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O 
~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <l...@intel.com>

All warnings (new ones prefixed by >>):

>> net/ipv6/xfrm6_tunnel.c:126:13: warning: address of array 
>> 'xfrm6_tn->spi_byspi' will always evaluate to 'true' 
>> [-Wpointer-bool-conversion]
                   xfrm6_tn->spi_byspi)
                   ~~~~~~~~~~^~~~~~~~~
   1 warning generated.

vim +126 net/ipv6/xfrm6_tunnel.c

   116  
   117  static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t 
*saddr)
   118  {
   119          struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
   120          u32 spi;
   121          struct xfrm6_tunnel_spi *x6spi;
   122          int index;
   123  
   124          if ((xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN ||
   125              xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX) &&
 > 126                  xfrm6_tn->spi_byspi)
   127                  xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN;
   128          else
   129                  xfrm6_tn->spi++;
   130  
   131          for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
   132                  index = __xfrm6_tunnel_spi_check(net, spi);
   133                  if (index >= 0)
   134                          goto alloc_spi;
   135  
   136                  if (spi == XFRM6_TUNNEL_SPI_MAX)
   137                          break;
   138          }
   139          for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) {
   140                  index = __xfrm6_tunnel_spi_check(net, spi);
   141                  if (index >= 0)
   142                          goto alloc_spi;
   143          }
   144          spi = 0;
   145          goto out;
   146  alloc_spi:
   147          xfrm6_tn->spi = spi;
   148          x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC);
   149          if (!x6spi)
   150                  goto out;
   151  
   152          memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
   153          x6spi->spi = spi;
   154          refcount_set(&x6spi->refcnt, 1);
   155  
   156          hlist_add_head_rcu(&x6spi->list_byspi, 
&xfrm6_tn->spi_byspi[index]);
   157  
   158          index = xfrm6_tunnel_spi_hash_byaddr(saddr);
   159          hlist_add_head_rcu(&x6spi->list_byaddr, 
&xfrm6_tn->spi_byaddr[index]);
   160  out:
   161          return spi;
   162  }
   163  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org

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