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 <jj@chaosbits.net>
Acked-by: Eliot Blennerhassett <linux@audioscience.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

3 files changed, 13 insertions, 3 deletions

diff --git a/sound/pci/asihpi/hpi6000.c b/sound/pci/asihpi/hpi6000.c
index f7e374e..1b9bf93 100644
--- 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
index 22c5fc6..2672f65 100644
--- 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
index dda4f1c..d67f4d3 100644
--- 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;
 }