ALSA: asihpi - Unsafe memory management when allocating control cache

I noticed that sound/pci/asihpi/hpicmn.c::hpi_alloc_control_cache() does not check the return value from kmalloc(), which may fail. If kmalloc() fails we'll dereference a null pointer and things will go bad fast. There are two memory allocations in that function and there's also the problem that the first may succeed and the second may fail and nothing is done about that either which will also go wrong down the line. Signed-off-by: Jesper Juhl <[email protected]> Acked-by: Eliot Blennerhassett <[email protected]> Signed-off-by: Takashi Iwai <[email protected]>
kyagi · Nov 2, 2010 · fd0977d · fd0977d
1 parent f746745
commit fd0977d
Show file tree

Hide file tree

Showing 3 changed files with 13 additions and 3 deletions.
diff --git a/sound/pci/asihpi/hpi6000.c b/sound/pci/asihpi/hpi6000.c
@@ -625,6 +625,8 @@ static short create_adapter_obj(struct hpi_adapter_obj *pao,
 			control_cache_size, (struct hpi_control_cache_info *)
 			&phw->control_cache[0]
 			);
+		if (!phw->p_cache)
+			pao->has_control_cache = 0;
 	} else
 		pao->has_control_cache = 0;
 

diff --git a/sound/pci/asihpi/hpi6205.c b/sound/pci/asihpi/hpi6205.c
@@ -644,6 +644,8 @@ static u16 create_adapter_obj(struct hpi_adapter_obj *pao,
 				interface->control_cache.size_in_bytes,
 				(struct hpi_control_cache_info *)
 				p_control_cache_virtual);
+			if (!phw->p_cache)
+				err = HPI_ERROR_MEMORY_ALLOC;
 		}
 		if (!err) {
 			err = hpios_locked_mem_get_phys_addr(&phw->

diff --git a/sound/pci/asihpi/hpicmn.c b/sound/pci/asihpi/hpicmn.c
@@ -571,14 +571,20 @@ struct hpi_control_cache *hpi_alloc_control_cache(const u32
 {
 	struct hpi_control_cache *p_cache =
 		kmalloc(sizeof(*p_cache), GFP_KERNEL);
+	if (!p_cache)
+		return NULL;
+	p_cache->p_info =
+		kmalloc(sizeof(*p_cache->p_info) * number_of_controls,
+			GFP_KERNEL);
+	if (!p_cache->p_info) {
+		kfree(p_cache);
+		return NULL;
+	}
 	p_cache->cache_size_in_bytes = size_in_bytes;
 	p_cache->control_count = number_of_controls;
 	p_cache->p_cache =
 		(struct hpi_control_cache_single *)pDSP_control_buffer;
 	p_cache->init = 0;
-	p_cache->p_info =
-		kmalloc(sizeof(*p_cache->p_info) * p_cache->control_count,
-		GFP_KERNEL);
 	return p_cache;
 }