tree: https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git queue-4.4 head: 6a08a9e7fb1525fa296d810d200954f6c18d07a2 commit: 4e3bc622004d182e7038229c8ffc989df2e3e413 [11/14] squashfs: add more sanity checks in id lookup config: arc-allyesconfig (attached as .config) compiler: arceb-elf-gcc (GCC) 9.3.0 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 # https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git/c... git remote add sashal-linux-stable https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git git fetch --no-tags sashal-linux-stable queue-4.4 git checkout 4e3bc622004d182e7038229c8ffc989df2e3e413 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): In file included from arch/arc/include/asm/bug.h:32, from include/linux/bug.h:4, from include/linux/thread_info.h:11, from include/asm-generic/preempt.h:4, from arch/arc/include/generated/asm/preempt.h:1, from include/linux/preempt.h:59, from include/linux/spinlock.h:50, from include/linux/wait.h:8, from include/linux/fs.h:5, from fs/squashfs/id.c:34: include/linux/cpumask.h: In function 'cpumask_check': include/linux/cpumask.h:117:19: warning: comparison of integer expressions of different signedness: 'unsigned int' and 'int' [-Wsign-compare] 117 | WARN_ON_ONCE(cpu >= nr_cpumask_bits); | ^~ include/asm-generic/bug.h:112:27: note: in definition of macro 'WARN_ON_ONCE' 112 | int __ret_warn_once = !!(condition); \ | ^~~~~~~~~ In file included from fs/squashfs/id.c:38: fs/squashfs/squashfs_fs.h: In function 'squashfs_block_size': fs/squashfs/squashfs_fs.h:135:24: warning: operand of ?: changes signedness from 'int' to 'u32' {aka 'unsigned int'} due to unsignedness of other operand [-Wsign-compare] 135 | return (size >> 25) ? -EIO : size; fs/squashfs/id.c: In function 'squashfs_read_id_index_table': 109 | for (n = 0; n < (indexes - 1); n++) { | ^ vim +109 fs/squashfs/id.c 68 69 70 /* 71 * Read uncompressed id lookup table indexes from disk into memory 72 */ 73 __le64 *squashfs_read_id_index_table(struct super_block *sb, 74 u64 id_table_start, u64 next_table, unsigned short no_ids) 75 { 76 unsigned int length = SQUASHFS_ID_BLOCK_BYTES(no_ids); 77 unsigned int indexes = SQUASHFS_ID_BLOCKS(no_ids); 78 int n; 79 __le64 *table; 80 u64 start, end; 81 82 TRACE("In read_id_index_table, length %d\n", length); 83 84 /* Sanity check values */ 85 86 /* there should always be at least one id */ 87 if (no_ids == 0) 88 return ERR_PTR(-EINVAL); 89 90 /* 91 * The computed size of the index table (length bytes) should exactly 92 * match the table start and end points 93 */ 94 if (length != (next_table - id_table_start)) 95 return ERR_PTR(-EINVAL); 96 97 table = squashfs_read_table(sb, id_table_start, length); 98 if (IS_ERR(table)) 99 return table; 100 101 /* 102 * table[0], table[1], ... table[indexes - 1] store the locations 103 * of the compressed id blocks. Each entry should be less than 104 * the next (i.e. table[0] < table[1]), and the difference between them 105 * should be SQUASHFS_METADATA_SIZE or less. table[indexes - 1] 106 * should be less than id_table_start, and again the difference 107 * should be SQUASHFS_METADATA_SIZE or less 108 */ --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org