[Mesa-dev] [PATCH 02/11] glsl/blob: Return false from grow_to_fit if we've ever failed

[Jason Ekstrand]

Otherwise we could have a failure followed by a smaller write that
succeeds and get a corrupted blob.  If we ever OOM, we should stop.

Cc: mesa-stable at lists.freedesktop.org
---
 src/compiler/glsl/blob.c | 7 ++++++-
 src/compiler/glsl/blob.h | 6 ++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/compiler/glsl/blob.c b/src/compiler/glsl/blob.c
index e837cdf..041a352 100644
--- a/src/compiler/glsl/blob.c
+++ b/src/compiler/glsl/blob.c
@@ -46,6 +46,9 @@ grow_to_fit(struct blob *blob, size_t additional)
    size_t to_allocate;
    uint8_t *new_data;
 
+   if (blob->out_of_memory)
+      return false;
+
    if (blob->size + additional <= blob->allocated)
       return true;
 
@@ -57,8 +60,10 @@ grow_to_fit(struct blob *blob, size_t additional)
    to_allocate = MAX2(to_allocate, blob->allocated + additional);
 
    new_data = realloc(blob->data, to_allocate);
-   if (new_data == NULL)
+   if (new_data == NULL) {
+      blob->out_of_memory = true;
       return false;
+   }
 
    blob->data = new_data;
    blob->allocated = to_allocate;
diff --git a/src/compiler/glsl/blob.h b/src/compiler/glsl/blob.h
index 940c81e..4cbbb01 100644
--- a/src/compiler/glsl/blob.h
+++ b/src/compiler/glsl/blob.h
@@ -55,6 +55,12 @@ struct blob {
 
    /** The number of bytes that have actual data written to them. */
    size_t size;
+
+   /**
+    * True if we've ever failed to realloc or if we go pas the end of a fixed
+    * allocation blob.
+    */
+   bool out_of_memory;
 };
 
 /* When done reading, the caller can ensure that everything was consumed by
-- 
2.5.0.400.gff86faf