[kbuild-all] net/sysctl_net.c:146:4: warning: Value stored to 'where' is never read [clang-analyzer-deadcode.DeadStores]

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 6e764bcd1cf72a2846c0e53d3975a09b242c04c9 commit: 31c4d2f160eb7b17cbead24dc6efed06505a3fee net: Ensure net namespace isolation of sysctls date: 4 months ago config: arm-randconfig-c002-20210824 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project d26000e4cc2bc65e207a84fa26cb6e374d60aa12) 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 arm cross compiling tool for clang build # apt-get install binutils-arm-linux-gnueabi # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 31c4d2f160eb7b17cbead24dc6efed06505a3fee # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm clang-analyzer If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; clang-analyzer warnings: (new ones prefixed by >>) Suppressed 1 warnings (1 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 1 warning generated. Suppressed 1 warnings (1 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. drivers/of/property.c:902:19: warning: Access to field 'full_name' results in a dereference of a null pointer [clang-analyzer-core.NullDereference] return kbasename(to_of_node(fwnode)->full_name); ^ include/linux/of.h:161:2: note: expanded from macro 'to_of_node' ({ \ ^ drivers/of/property.c:902:19: note: '?' condition is false return kbasename(to_of_node(fwnode)->full_name); ^ include/linux/of.h:164:3: note: expanded from macro 'to_of_node' is_of_node(__to_of_node_fwnode) ? \ ^ drivers/of/property.c:902:19: note: Access to field 'full_name' results in a dereference of a null pointer return kbasename(to_of_node(fwnode)->full_name); ^ include/linux/of.h:161:2: note: expanded from macro 'to_of_node' ({ \ ^ drivers/of/property.c:908:7: warning: Access to field 'parent' results in a dereference of a null pointer [clang-analyzer-core.NullDereference] if (!to_of_node(fwnode)->parent) ^ include/linux/of.h:161:2: note: expanded from macro 'to_of_node' ({ \ ^ drivers/of/property.c:908:7: note: '?' condition is false if (!to_of_node(fwnode)->parent) ^ include/linux/of.h:164:3: note: expanded from macro 'to_of_node' is_of_node(__to_of_node_fwnode) ? \ ^ drivers/of/property.c:908:7: note: Access to field 'parent' results in a dereference of a null pointer if (!to_of_node(fwnode)->parent) ^ include/linux/of.h:161:2: note: expanded from macro 'to_of_node' ({ \ ^ 1 warning generated. Suppressed 1 warnings (1 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. drivers/base/power/main.c:469:3: warning: Value stored to 'usecs' is never read [clang-analyzer-deadcode.DeadStores] usecs = 1; ^ ~ drivers/base/power/main.c:469:3: note: Value stored to 'usecs' is never read usecs = 1; ^ ~ Suppressed 1 warnings (1 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 1 warning generated. Suppressed 1 warnings (1 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 1 warning generated. Suppressed 1 warnings (1 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. where = "module"; ^ ~~~~~~~~ net/sysctl_net.c:146:4: note: Value stored to 'where' is never read where = "module"; ^ ~~~~~~~~ net/sysctl_net.c:148:4: warning: Value stored to 'where' is never read [clang-analyzer-deadcode.DeadStores] where = "kernel"; ^ ~~~~~~~~ net/sysctl_net.c:148:4: note: Value stored to 'where' is never read where = "kernel"; ^ ~~~~~~~~ Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 1 warning generated. Suppressed 1 warnings (1 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. net/core/net-sysfs.c:1719:2: warning: Value stored to 'txq' is never read [clang-analyzer-deadcode.DeadStores] txq = real_tx; ^ ~~~~~~~ net/core/net-sysfs.c:1719:2: note: Value stored to 'txq' is never read txq = real_tx; ^ ~~~~~~~ Suppressed 3 warnings (3 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 2 warnings generated. Suppressed 2 warnings (2 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 3 warnings generated. Suppressed 3 warnings (3 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 3 warnings generated. Suppressed 3 warnings (3 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 3 warnings generated. Suppressed 3 warnings (3 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 5 warnings generated. net/bluetooth/msft.c:372:2: warning: Value stored to 'rp' is never read [clang-analyzer-deadcode.DeadStores] rp = (struct msft_rp_le_cancel_monitor_advertisement *)skb->data; ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ net/bluetooth/msft.c:372:2: note: Value stored to 'rp' is never read rp = (struct msft_rp_le_cancel_monitor_advertisement *)skb->data; ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ net/bluetooth/msft.c:422:2: warning: Value stored to 'rp' is never read [clang-analyzer-deadcode.DeadStores] rp = (struct msft_rp_le_set_advertisement_filter_enable *)skb->data; vim +/where +146 net/sysctl_net.c 117 118 /* Verify that sysctls for non-init netns are safe by either: 119 * 1) being read-only, or 120 * 2) having a data pointer which points outside of the global kernel/module 121 * data segment, and rather into the heap where a per-net object was 122 * allocated. 123 */ 124 static void ensure_safe_net_sysctl(struct net *net, const char *path, 125 struct ctl_table *table) 126 { 127 struct ctl_table *ent; 128 129 pr_debug("Registering net sysctl (net %p): %s\n", net, path); 130 for (ent = table; ent->procname; ent++) { 131 unsigned long addr; 132 const char *where; 133 134 pr_debug(" procname=%s mode=%o proc_handler=%ps data=%p\n", 135 ent->procname, ent->mode, ent->proc_handler, ent->data); 136 137 /* If it's not writable inside the netns, then it can't hurt. */ 138 if ((ent->mode & 0222) == 0) { 139 pr_debug(" Not writable by anyone\n"); 140 continue; 141 } 142 143 /* Where does data point? */ 144 addr = (unsigned long)ent->data; 145 if (is_module_address(addr)) 147 else if (core_kernel_data(addr)) 148 where = "kernel"; 149 else 150 continue; 151 152 /* If it is writable and points to kernel/module global 153 * data, then it's probably a netns leak. 154 */ 155 WARN(1, "sysctl %s/%s: data points to %s global data: %ps\n", 156 path, ent->procname, where, ent->data); 157 158 /* Make it "safe" by dropping writable perms */ 159 ent->mode &= ~0222; 160 } 161 } 162 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org