Fix bug #81472: Support large device major/minor number

linericyang · nikic · commit 9ad8fadcbbb0 · 2021-09-24T09:57:32.000+02:00
Latest linux kernel use large number (12 bits for major device, 20 bits for minor device). Current code only supports previous standard (5 chars), which means 8 bits for major and 8 bits for minor device. It will fail if device number is out of that range. So this patch increases device number read from /proc/self/maps file. Closes GH-7512.
diff --git a/NEWS b/NEWS
@@ -21,6 +21,10 @@ PHP                                                                        NEWS
   . Fixed bug #61700 (FILTER_FLAG_IPV6/FILTER_FLAG_NO_PRIV|RES_RANGE failing).
     (cmb, Nikita)
 
+- Opcache:
+  . Fixed bug #81472 (Cannot support large linux major/minor device number when
+    read /proc/self/maps). (Lin Yang)
+
 - PCRE:
   . Fixed bug #81424 (PCRE2 10.35 JIT performance regression). (cmb)
 
diff --git a/ext/opcache/ZendAccelerator.c b/ext/opcache/ZendAccelerator.c
@@ -2803,11 +2803,11 @@ static void accel_move_code_to_huge_pages(void)
 	f = fopen("/proc/self/maps", "r");
 	if (f) {
 		long unsigned int  start, end, offset, inode;
-		char perm[5], dev[6], name[MAXPATHLEN];
+		char perm[5], dev[10], name[MAXPATHLEN];
 		int ret;
 
 		while (1) {
-			ret = fscanf(f, "%lx-%lx %4s %lx %5s %ld %s\n", &start, &end, perm, &offset, dev, &inode, name);
+			ret = fscanf(f, "%lx-%lx %4s %lx %9s %ld %s\n", &start, &end, perm, &offset, dev, &inode, name);
 			if (ret == 7) {
 				if (perm[0] == 'r' && perm[1] == '-' && perm[2] == 'x' && name[0] == '/') {
 					long unsigned int  seg_start = ZEND_MM_ALIGNED_SIZE_EX(start, huge_page_size);
