Re: [PATCH] Bluetooth: Fix type of len in rfcomm_sock_{bind,getsockopt_old}()

[kernel test robot <lkp@intel.com>]

Hi Andrej,

kernel test robot noticed the following build errors:

[auto build test ERROR on bluetooth-next/master]
[also build test ERROR on bluetooth/master linus/master v6.12-rc1 next-20241004]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Andrej-Shadura/Bluetooth-Fix-type-of-len-in-rfcomm_sock_-bind-getsockopt_old/20241002-221656
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git master
patch link:    https://lore.kernel.org/r/20241002141217.663070-1-andrew.shadura%40collabora.co.uk
patch subject: [PATCH] Bluetooth: Fix type of len in rfcomm_sock_{bind,getsockopt_old}()
config: arm-randconfig-001-20241004 (https://download.01.org/0day-ci/archive/20241004/202410042221.Phncg973-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project fef3566a25ff0e34fb87339ba5e13eca17cec00f)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241004/202410042221.Phncg973-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410042221.Phncg973-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from net/bluetooth/rfcomm/sock.c:32:
   In file included from include/net/bluetooth/bluetooth.h:30:
   In file included from include/net/sock.h:46:
   In file included from include/linux/netdevice.h:38:
   In file included from include/net/net_namespace.h:43:
   In file included from include/linux/skbuff.h:17:
   In file included from include/linux/bvec.h:10:
   In file included from include/linux/highmem.h:8:
   In file included from include/linux/cacheflush.h:5:
   In file included from arch/arm/include/asm/cacheflush.h:10:
   In file included from include/linux/mm.h:2232:
   include/linux/vmstat.h:517:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     517 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
>> net/bluetooth/rfcomm/sock.c:339:8: error: call to '__compiletime_assert_549' declared with 'error' attribute: min(sizeof(sa), addr_len) signedness error
     339 |         len = min(sizeof(sa), addr_len);
         |               ^
   include/linux/minmax.h:129:19: note: expanded from macro 'min'
     129 | #define min(x, y)       __careful_cmp(min, x, y)
         |                         ^
   include/linux/minmax.h:105:2: note: expanded from macro '__careful_cmp'
     105 |         __careful_cmp_once(op, x, y, __UNIQUE_ID(x_), __UNIQUE_ID(y_))
         |         ^
   include/linux/minmax.h:100:2: note: expanded from macro '__careful_cmp_once'
     100 |         BUILD_BUG_ON_MSG(!__types_ok(x,y,ux,uy),        \
         |         ^
   note: (skipping 2 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
   include/linux/compiler_types.h:498:2: note: expanded from macro '_compiletime_assert'
     498 |         __compiletime_assert(condition, msg, prefix, suffix)
         |         ^
   include/linux/compiler_types.h:491:4: note: expanded from macro '__compiletime_assert'
     491 |                         prefix ## suffix();                             \
         |                         ^
   <scratch space>:174:1: note: expanded from here
     174 | __compiletime_assert_549
         | ^
   1 warning and 1 error generated.


vim +339 net/bluetooth/rfcomm/sock.c

   326	
   327	static int rfcomm_sock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
   328	{
   329		struct sockaddr_rc sa;
   330		struct sock *sk = sock->sk;
   331		int err = 0;
   332		size_t len;
   333	
   334		if (!addr || addr_len < offsetofend(struct sockaddr, sa_family) ||
   335		    addr->sa_family != AF_BLUETOOTH)
   336			return -EINVAL;
   337	
   338		memset(&sa, 0, sizeof(sa));
 > 339		len = min(sizeof(sa), addr_len);
   340		memcpy(&sa, addr, len);
   341	
   342		BT_DBG("sk %p %pMR", sk, &sa.rc_bdaddr);
   343	
   344		lock_sock(sk);
   345	
   346		if (sk->sk_state != BT_OPEN) {
   347			err = -EBADFD;
   348			goto done;
   349		}
   350	
   351		if (sk->sk_type != SOCK_STREAM) {
   352			err = -EINVAL;
   353			goto done;
   354		}
   355	
   356		write_lock(&rfcomm_sk_list.lock);
   357	
   358		if (sa.rc_channel &&
   359		    __rfcomm_get_listen_sock_by_addr(sa.rc_channel, &sa.rc_bdaddr)) {
   360			err = -EADDRINUSE;
   361		} else {
   362			/* Save source address */
   363			bacpy(&rfcomm_pi(sk)->src, &sa.rc_bdaddr);
   364			rfcomm_pi(sk)->channel = sa.rc_channel;
   365			sk->sk_state = BT_BOUND;
   366		}
   367	
   368		write_unlock(&rfcomm_sk_list.lock);
   369	
   370	done:
   371		release_sock(sk);
   372		return err;
   373	}
   374	

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