Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 277 insertions, 0 deletions

diff --git a/security/sandbox/linux/broker/SandboxBrokerRealpath.cpp b/security/sandbox/linux/broker/SandboxBrokerRealpath.cpp
new file mode 100644
index 0000000000..b129af57fd
--- /dev/null
+++ b/security/sandbox/linux/broker/SandboxBrokerRealpath.cpp
@@ -0,0 +1,277 @@
+/*
+ * Copyright (c) 2003 Constantin S. Svintsoff <kostik@iclub.nsu.ru>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The names of the authors may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * This is originally from:
+ * android-n-mr2-preview-1-303-gccec0f4c1
+ * libc/upstream-freebsd/lib/libc/stdlib/realpath.c
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)realpath.c	8.1 (Berkeley) 2/16/94";
+#endif /* LIBC_SCCS and not lint */
+#include <sys/param.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "base/string_util.h"
+#include "SandboxBroker.h"
+
+// Original copy in, but not usable from here:
+// toolkit/crashreporter/google-breakpad/src/common/linux/linux_libc_support.cc
+static size_t my_strlcat(char* s1, const char* s2, size_t len) {
+  size_t pos1 = 0;
+
+  while (pos1 < len && s1[pos1] != '\0') pos1++;
+
+  if (pos1 == len) return pos1;
+
+  return pos1 + base::strlcpy(s1 + pos1, s2, len - pos1);
+}
+
+namespace mozilla {
+
+/*
+ * Original: realpath
+ * Find the real name of path, by removing all ".", ".." and symlink
+ * components.  Returns (resolved) on success, or (NULL) on failure,
+ * in which case the path which caused trouble is left in (resolved).
+ * Changes:
+ * Resolve relative paths, but don't allow backing out of a symlink
+ * target. Fail with permission error if any dir is writable.
+ */
+char* SandboxBroker::SymlinkPath(const Policy* policy,
+                                 const char* __restrict path,
+                                 char* __restrict resolved, int* perms) {
+  struct stat sb;
+  char *p, *q, *s;
+  size_t left_len, resolved_len, backup_allowed;
+  unsigned symlinks;
+  int m, slen;
+  char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX];
+
+  if (*perms) {
+    *perms = 0;
+  }
+  if (path == NULL) {
+    errno = EINVAL;
+    return (NULL);
+  }
+  if (path[0] == '\0') {
+    errno = ENOENT;
+    return (NULL);
+  }
+  if (resolved == NULL) {
+    resolved = (char*)malloc(PATH_MAX);
+    if (resolved == NULL) return (NULL);
+    m = 1;
+  } else
+    m = 0;
+  symlinks = 0;
+  backup_allowed = PATH_MAX;
+  if (path[0] == '/') {
+    resolved[0] = '/';
+    resolved[1] = '\0';
+    if (path[1] == '\0') return (resolved);
+    resolved_len = 1;
+    left_len = base::strlcpy(left, path + 1, sizeof(left));
+  } else {
+    if (getcwd(resolved, PATH_MAX) == NULL) {
+      if (m)
+        free(resolved);
+      else {
+        resolved[0] = '.';
+        resolved[1] = '\0';
+      }
+      return (NULL);
+    }
+    resolved_len = strlen(resolved);
+    left_len = base::strlcpy(left, path, sizeof(left));
+  }
+  if (left_len >= sizeof(left) || resolved_len >= PATH_MAX) {
+    if (m) free(resolved);
+    errno = ENAMETOOLONG;
+    return (NULL);
+  }
+
+  /*
+   * Iterate over path components in `left'.
+   */
+  while (left_len != 0) {
+    /*
+     * Extract the next path component and adjust `left'
+     * and its length.
+     */
+    p = strchr(left, '/');
+    s = p ? p : left + left_len;
+    if (s - left >= (ssize_t)sizeof(next_token)) {
+      if (m) free(resolved);
+      errno = ENAMETOOLONG;
+      return (NULL);
+    }
+    memcpy(next_token, left, s - left);
+    next_token[s - left] = '\0';
+    left_len -= s - left;
+    if (p != NULL) memmove(left, s + 1, left_len + 1);
+    if (resolved[resolved_len - 1] != '/') {
+      if (resolved_len + 1 >= PATH_MAX) {
+        if (m) free(resolved);
+        errno = ENAMETOOLONG;
+        return (NULL);
+      }
+      resolved[resolved_len++] = '/';
+      resolved[resolved_len] = '\0';
+    }
+    if (next_token[0] == '\0') {
+      /* Handle consequential slashes. */
+      continue;
+    } else if (strcmp(next_token, ".") == 0)
+      continue;
+    else if (strcmp(next_token, "..") == 0) {
+      /*
+       * Strip the last path component except when we have
+       * single "/"
+       */
+      if (resolved_len > 1) {
+        if (backup_allowed > 0) {
+          resolved[resolved_len - 1] = '\0';
+          q = strrchr(resolved, '/') + 1;
+          *q = '\0';
+          resolved_len = q - resolved;
+          backup_allowed--;
+        } else {
+          // Backing out past a symlink target.
+          // We don't allow this, because it can eliminate
+          // permissions we accumulated while descending.
+          if (m) free(resolved);
+          errno = EPERM;
+          return (NULL);
+        }
+      }
+      continue;
+    }
+
+    /*
+     * Append the next path component and lstat() it.
+     */
+    resolved_len = my_strlcat(resolved, next_token, PATH_MAX);
+    backup_allowed++;
+    if (resolved_len >= PATH_MAX) {
+      if (m) free(resolved);
+      errno = ENAMETOOLONG;
+      return (NULL);
+    }
+    if (lstat(resolved, &sb) != 0) {
+      if (m) free(resolved);
+      return (NULL);
+    }
+    if (S_ISLNK(sb.st_mode)) {
+      if (symlinks++ > MAXSYMLINKS) {
+        if (m) free(resolved);
+        errno = ELOOP;
+        return (NULL);
+      }
+      /* Our changes start here:
+       * It's a symlink, check for write permissions on the path where
+       * it sits in, in which case we won't resolve and just error out. */
+      int link_path_perms = policy->Lookup(resolved);
+      if (link_path_perms & MAY_WRITE) {
+        if (m) free(resolved);
+        errno = EPERM;
+        return (NULL);
+      } else {
+        /* Accumulate permissions so far */
+        *perms |= link_path_perms;
+      }
+      /* Original symlink lookup code */
+      slen = readlink(resolved, symlink, sizeof(symlink) - 1);
+      if (slen < 0) {
+        if (m) free(resolved);
+        return (NULL);
+      }
+      symlink[slen] = '\0';
+      if (symlink[0] == '/') {
+        resolved[1] = 0;
+        resolved_len = 1;
+      } else if (resolved_len > 1) {
+        /* Strip the last path component. */
+        resolved[resolved_len - 1] = '\0';
+        q = strrchr(resolved, '/') + 1;
+        *q = '\0';
+        resolved_len = q - resolved;
+      }
+
+      /*
+       * If there are any path components left, then
+       * append them to symlink. The result is placed
+       * in `left'.
+       */
+      if (p != NULL) {
+        if (symlink[slen - 1] != '/') {
+          if (slen + 1 >= (ssize_t)sizeof(symlink)) {
+            if (m) free(resolved);
+            errno = ENAMETOOLONG;
+            return (NULL);
+          }
+          symlink[slen] = '/';
+          symlink[slen + 1] = 0;
+        }
+        left_len = my_strlcat(symlink, left, sizeof(symlink));
+        if (left_len >= sizeof(left)) {
+          if (m) free(resolved);
+          errno = ENAMETOOLONG;
+          return (NULL);
+        }
+      }
+      left_len = base::strlcpy(left, symlink, sizeof(left));
+      backup_allowed = 0;
+    } else if (!S_ISDIR(sb.st_mode) && p != NULL) {
+      if (m) free(resolved);
+      errno = ENOTDIR;
+      return (NULL);
+    }
+  }
+
+  /*
+   * Remove trailing slash except when the resolved pathname
+   * is a single "/".
+   */
+  if (resolved_len > 1 && resolved[resolved_len - 1] == '/')
+    resolved[resolved_len - 1] = '\0';
+
+  /* Accumulate permissions. */
+  *perms |= policy->Lookup(resolved);
+
+  return (resolved);
+}
+
+}  // namespace mozilla