Bug 2066: squid does not do chdir() after chroot()

The earlier workaround applied only fixed 1 of the 3 places performing
chroot().
 This makes chroot and chdir integral parts of setting up Squids running
directory and alters teh chroot() calls to be mainSetCwnd() calls. Which
fixes several potential problems with core dumps from squid -z or -k
executions ending up in unexpected locations, regardless of whether
chroot() and coredump_dir are configured.

 Detected by Coverity Scan. Issue 740335.

diff --git a/src/main.cc b/src/main.cc
index 3f04daa5cf77cc0fb492214efe0c2bc107beee4a..7e2ae37989b15ad40650e4201eac9e1c18dd9200 100644 (file)
--- a/src/main.cc
+++ b/src/main.cc
@@ -951,20 +951,31 @@ setEffectiveUser(void)
     }
 }
 
+/// set the working directory.
 static void
 mainSetCwd(void)
 {
     char pathbuf[MAXPATHLEN];
+    static bool chrooted = false;
 
-    if (Config.coredump_dir) {
-        if (0 == strcmp("none", Config.coredump_dir)) {
-            (void) 0;
-        } else if (chdir(Config.coredump_dir) == 0) {
-            debugs(0, DBG_IMPORTANT, "Set Current Directory to " << Config.coredump_dir);
-            return;
-        } else {
-            debugs(50, DBG_CRITICAL, "chdir: " << Config.coredump_dir << ": " << xstrerror());
-        }
+    if (Config.chroot_dir && !chrooted) {
+        chrooted = true;
+
+        if (chroot(Config.chroot_dir) != 0);
+            fatal("failed to chroot");
+
+        strncpy(pathbuf, "/", sizeof(pathbuf)-1);
+    }
+
+    if (Config.coredump_dir && strcmp("none", Config.coredump_dir) == 0) {
+        strncpy(pathbuf, Config.coredump_dir, sizeof(pathbuf)-1);
+    }
+
+    if (chdir(pathbuf) == 0) {
+        debugs(0, DBG_IMPORTANT, "Set Current Directory to " << Config.coredump_dir);
+        return;
+    } else {
+        debugs(50, DBG_CRITICAL, "chdir: " << pathbuf << ": " << xstrerror());
     }
 
     /* If we don't have coredump_dir or couldn't cd there, report current dir */
@@ -979,10 +990,7 @@ static void
 mainInitialize(void)
 {
     /* chroot if configured to run inside chroot */
-
-    if (Config.chroot_dir && (chroot(Config.chroot_dir) != 0 || chdir("/") != 0)) {
-        fatal("failed to chroot");
-    }
+    mainSetCwd();
 
     if (opt_catch_signals) {
         squid_signal(SIGSEGV, death, SA_NODEFER | SA_RESETHAND);
@@ -1425,11 +1433,8 @@ SquidMain(int argc, char **argv)
     /* send signal to running copy and exit */
     if (opt_send_signal != -1) {
         /* chroot if configured to run inside chroot */
-
+        mainSetCwd();
         if (Config.chroot_dir) {
-            if (chroot(Config.chroot_dir))
-                fatal("failed to chroot");
-
             no_suid();
         } else {
             leave_suid();
@@ -1451,10 +1456,7 @@ SquidMain(int argc, char **argv)
 
     if (opt_create_swap_dirs) {
         /* chroot if configured to run inside chroot */
-
-        if (Config.chroot_dir && chroot(Config.chroot_dir)) {
-            fatal("failed to chroot");
-        }
+        mainSetCwd();
 
         setEffectiveUser();
         debugs(0, DBG_CRITICAL, "Creating missing swap directories");