Bug 706761: Don't "reduce" %pipe% file names for permission validation

For regular file names, we try to simplfy relative paths before we use them.

Because the %pipe% device can, effectively, accept command line calls, we
shouldn't be simplifying that string, because the command line syntax can end
up confusing the path simplifying code. That can result in permitting a pipe
command which does not match what was originally permitted.

Special case "%pipe" in the validation code so we always deal with the entire
string.

2 files changed, 64 insertions, 23 deletions

diff --git a/base/gpmisc.c b/base/gpmisc.c
index 5f39ebba7..2fb87f769 100644
--- a/base/gpmisc.c
+++ b/base/gpmisc.c
@@ -1076,16 +1076,29 @@ gp_validate_path_len(const gs_memory_t *mem,
              && !memcmp(path + cdirstrl, dirsepstr, dirsepstrl)) {
           prefix_len = 0;
     }
-    rlen = len+1;
-    bufferfull = (char *)gs_alloc_bytes(mem->thread_safe_memory, rlen + prefix_len, "gp_validate_path");
-    if (bufferfull == NULL)
-        return gs_error_VMerror;
-
-    buffer = bufferfull + prefix_len;
-    if (gp_file_name_reduce(path, (uint)len, buffer, &rlen) != gp_combine_success)
-        return gs_error_invalidfileaccess;
-    buffer[rlen] = 0;
 
+    /* "%pipe%" do not follow the normal rules for path definitions, so we
+       don't "reduce" them to avoid unexpected results
+     */
+    if (len > 5 && memcmp(path, "%pipe", 5) != 0) {
+        bufferfull = buffer = (char *)gs_alloc_bytes(mem->thread_safe_memory, len + 1, "gp_validate_path");
+        if (buffer == NULL)
+            return gs_error_VMerror;
+        memcpy(buffer, path, len);
+        buffer[len] = 0;
+        rlen = len;
+    }
+    else {
+        rlen = len+1;
+        bufferfull = (char *)gs_alloc_bytes(mem->thread_safe_memory, rlen + prefix_len, "gp_validate_path");
+        if (bufferfull == NULL)
+            return gs_error_VMerror;
+
+        buffer = bufferfull + prefix_len;
+        if (gp_file_name_reduce(path, (uint)len, buffer, &rlen) != gp_combine_success)
+            return gs_error_invalidfileaccess;
+        buffer[rlen] = 0;
+    }
     while (1) {
         switch (mode[0])
         {
diff --git a/base/gslibctx.c b/base/gslibctx.c
index eb566ed06..d2a1aa91d 100644
--- a/base/gslibctx.c
+++ b/base/gslibctx.c
@@ -740,14 +740,28 @@ gs_add_control_path_len_flags(const gs_memory_t *mem, gs_path_control_t type, co
             return gs_error_rangecheck;
     }
 
-    rlen = len+1;
-    buffer = (char *)gs_alloc_bytes(core->memory, rlen, "gp_validate_path");
-    if (buffer == NULL)
-        return gs_error_VMerror;
+    /* "%pipe%" do not follow the normal rules for path definitions, so we
+       don't "reduce" them to avoid unexpected results
+     */
+    if (len > 5 && memcmp(path, "%pipe", 5) != 0) {
+        buffer = (char *)gs_alloc_bytes(core->memory, len + 1, "gs_add_control_path_len");
+        if (buffer == NULL)
+            return gs_error_VMerror;
+        memcpy(buffer, path, len);
+        buffer[len] = 0;
+        rlen = len;
+    }
+    else {
+        rlen = len + 1;
 
-    if (gp_file_name_reduce(path, (uint)len, buffer, &rlen) != gp_combine_success)
-        return gs_error_invalidfileaccess;
-    buffer[rlen] = 0;
+        buffer = (char *)gs_alloc_bytes(core->memory, rlen, "gs_add_control_path_len");
+        if (buffer == NULL)
+            return gs_error_VMerror;
+
+        if (gp_file_name_reduce(path, (uint)len, buffer, &rlen) != gp_combine_success)
+            return gs_error_invalidfileaccess;
+        buffer[rlen] = 0;
+    }
 
     n = control->num;
     for (i = 0; i < n; i++)
@@ -833,14 +847,28 @@ gs_remove_control_path_len_flags(const gs_memory_t *mem, gs_path_control_t type,
             return gs_error_rangecheck;
     }
 
-    rlen = len+1;
-    buffer = (char *)gs_alloc_bytes(core->memory, rlen, "gp_validate_path");
-    if (buffer == NULL)
-        return gs_error_VMerror;
+    /* "%pipe%" do not follow the normal rules for path definitions, so we
+       don't "reduce" them to avoid unexpected results
+     */
+    if (len > 5 && memcmp(path, "%pipe", 5) != 0) {
+        buffer = (char *)gs_alloc_bytes(core->memory, len + 1, "gs_remove_control_path_len");
+        if (buffer == NULL)
+            return gs_error_VMerror;
+        memcpy(buffer, path, len);
+        buffer[len] = 0;
+        rlen = len;
+    }
+    else {
+        rlen = len+1;
 
-    if (gp_file_name_reduce(path, (uint)len, buffer, &rlen) != gp_combine_success)
-        return gs_error_invalidfileaccess;
-    buffer[rlen] = 0;
+        buffer = (char *)gs_alloc_bytes(core->memory, rlen, "gs_remove_control_path_len");
+        if (buffer == NULL)
+            return gs_error_VMerror;
+
+        if (gp_file_name_reduce(path, (uint)len, buffer, &rlen) != gp_combine_success)
+            return gs_error_invalidfileaccess;
+        buffer[rlen] = 0;
+    }
 
     n = control->num;
     for (i = 0; i < n; i++) {